MAX7360ETL+ - Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

EVALUATION KIT AVAILABLE

General Description

The MAX7360 I2C-interfaced peripheral provides micro-

processors with management of up to 64 key switches,

with an additional eight LED drivers/GPIOs that feature

constant-current, PWM intensity control, and rotary

switch control options.

The key-switch drivers interface with metallic or resis-

tive switches with on-resistances up to 5kI. Key inputs

are monitored statically, not dynamically, to ensure

low-EMI operation. The MAX7360 features autosleep

and autowake modes to further minimize the power

consumption of the device. The autosleep feature puts

the device in a low-power state (1FA typ) after a sleep

timeout period. The autowake feature configures the

MAX7360 to return to normal operating mode from sleep

upon a keypress.

The key controller debounces and maintains a FIFO of

keypress and release events (including autorepeat, if

enabled). An interrupt (INTK) output can be configured

to alert keypresses, as they occur, or at maximum rate.

There are eight open-drain I/O ports, which can be used

to drive LEDs. The maximum constant-current level for

each open-drain port is 20mA. The intensity of the LED

on each open-drain port can be individually adjusted

through a 256-step PWM control. An input port pair

(PORT6, PORT7) can be configured to accept 2-bit gray

code inputs from a rotary switch. In addition, if not used

for key-switch control, up to six column pins can be used

as general-purpose open-drain outputs (GPOs) for LED

drive or logic control.

The MAX7360 is offered in a 40-pin (5mm x 5mm)

thin QFN package with an exposed pad, and a small

36-bump wafer level package (WLP) for cell phones,

pocket PCs, and other portable consumer electronic

applications. The MAX7360 operates over the -40NC to

+85NC extended temperature range.

Applications

Cell Phones

PDAs

Handheld Games

Portable Consumer Electronics

Printers

Instrumentation

Features

S Integrated ESD Protection

±8kV IEC 61000-4-2 Contact Discharge

±15kV IEC 61000-4-2 Air-Gap Discharge

S +14V Tolerant, Open-Drain I/O Ports Capable of

Constant-Current LED Drive

S Rotary Switch-Capable Input Pair (PORT6, PORT7)

S 256-Step PWM Individual LED Intensity Control

S Individual LED Blink Rates and Common LED

Fade In/Out Rates from 256ms to 4096ms

S FIFO Queues Up to 16 Debounced Key Events

S User-Configurable Key Debounce (9ms to 40ms)

S Keyscan Uses Static Matrix Monitoring for Low

EMI Operation

S +1.62V to +3.6V Operation

S Monitors Up to 64 Keys

S Key-Switch Interrupt (INTK) on Each Debounced

Event/FIFO Level, or End of Definable Time Period

S Port Interrupt (INTI) for Input Ports for Special-Key

Functions

S 400kbps, +5.5V Tolerant 2-Wire Serial Interface

with Selectable Bus Timeout

S Four I2C Address Choices

19-4566; Rev 2; 1/13

Simplified Block Diagram

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

Pin Configurations appear at end of data sheet.

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX7360ETL+ -40°C to +85°C 40 TQFN-EP*

MAX7360EWX+ -40°C to +85°C 36 WLP

MAX7360

AD0

PORT7

PORT6

PORT0

COL_(8x)

ROW_(8x)

INTK

INTI

SDA

SCL

ROTARY

SWITCH

+14V

8 x 8

+1.8V

For pricing, delivery, and ordering information, please contact Maxim Direct at

1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.

2 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect device reliability.

VCC to GND ............................................................. -0.3V to +4V

COL0–COL7, ROW0–ROW7 to GND ...................... -0.3V to +4V

SDA, SCL, AD0, INTI, INTK to GND ........................ -0.3V to +6V

PORT0–PORT7 to GND ......................................... -0.3V to +16V

All Other Pins to GND ................................ -0.3V to (VCC + 0.3V)

DC Current on PORT0–PORT7, COL2–COL7 ....................25mA

GND Current .......................................................................80mA

Continuous Power Dissipation (TA = +70NC)

TQFN (derate 22.2mW/NC above +70NC) .................. 1777mW

WLP (derate 21.7mW/NC above +70NC) .................... 1739mW

Operating Temperature Range .......................... -40NC to +85NC

Junction Temperature .....................................................+150NC

Storage Temperature Range ............................ -65NC to +150NC

ESD Protection

Human Body Model (RD = 1.5kI, CS = 100pF)

All Pins .............................................................................Q2kV

IEC 61000-4-2 (RD = 330I, CS = 150pF)

Contact Discharge

ROW0–ROW7, COL0–COL7, PORT0–PORT7 to GND ....Q8kV

Air-Gap Discharge

ROW0–ROW7, COL0–COL7, PORT0–PORT7 to GND ..Q15kV

Lead Temperature (TQFN only; soldering, 10s) ..............+300NC

Soldering Temperature (reflow) .......................................+260NC

ELECTRICAL CHARACTERISTICS

(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 2, 3)

ABSOLUTE MAXIMUM RATINGS

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a single-

layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.

TQFN

Junction-to-Ambient Thermal Resistance (BJA) ......... 45NC/W

Junction-to-Case Thermal Resistance (BJC) ................ 2NC/W

WLP

Junction-to-Ambient Thermal Resistance (BJA) WLP . 46NC/W

PACKAGE THERMAL CHARACTERISTICS (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Operating Supply Voltage VCC 1.62 3.3 3.6 V

External Supply Voltage

PORT0–PORT7 VPORT_ 14 V

Operating Supply Current ICC

All key switches open, oscillator running,

COL2–COL7 configured as key switches,

VPORT_ = VCC

34 50

N keys pressed 34 +

20 x N

Sleep-Mode Supply Current ISL 1.3 3 FA

Key-Switch Source Current IKEY 20 35 FA

Key-Switch Source Voltage VKEY 0.43 0.5 V

Key-Switch Resistance RKEY (Note 4) 5 kI

Startup Time from Shutdown tSTART 2 2.4 ms

Output Low Voltage

COL2–COL7 VOL ISINK = 10mA 0.5 V

Oscillator Frequency (PWM

Clock) fOSC

TA = +25NC, VCC = +2.61V 125 128 131

kHz

TA = TMIN to TMAX, VCC P 3.6V 102 164

Oscillator Frequency Variation DfOSC TA = +25NC-7 +14 %

Key-Scan Frequency fKEY Derived from oscillator clock 64 kHz

3Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 2, 3)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

GPIO SPECIFICATIONS

Input High Voltage

PORT0–PORT7 VIH 0.7 x

VCC V

Input Low Voltage

PORT0–PORT7 VIL 0.3 x

VCC V

Input Leakage Current

PORT0–PORT7 IIN VIN P VCC -0.25 +0.25 FA

VCC < VIN -1 +5

Output Low Voltage

PORT0–PORT7 VOL ISINK < 20mA 0.6 V

Input Capacitance

PORT0–PORT7 20 pF

10mA Port Sinking Current

PORT0–PORT7

VCC = +1.62V to +3.6V, TA = +25NC8.55 11.52

VCC = +3.3V, VOL = +1V 8.67 9.76 10.51

20mA Port Sinking Current

PORT0–PORT7

VCC = +1.62V to +3.6V, TA = +25NC19.40 21.33

VCC = +3.3V, VOL = +1V 19.55 20 20.69

Port Sink Current Variation VCC = +3.3V, VOL = +1V, TA = +25NC,

20mA output mode +Q1.5 +Q2.4 %

Output Logic-Low Voltage

INTI, INTK ISINK = 10mA 0.6 V

PWM Frequency fPWM Derived from oscillator clock 500 Hz

SERIAL-INTERFACE SPECIFICATIONS

Input High Voltage

SDA, SCL, AD0 VIH 0.7 x

VCC V

Input Low Voltage

SDA, SCL, AD0 VIL 0.3 x

VCC V

Input Leakage Current

SDA, SCL, AD0 IIN VIN P VCC -0.25 +0.25 FA

VIN > VCC -0.5 +0.5

Output Low Voltage

SDA VOL ISINK = 6mA 0.6 V

Input Capacitance

SDA, SCL, AD0 CIN 10 pF

I2C TIMING SPECIFICATIONS

SCL Serial-Clock Frequency fSCL Bus timeout disabled 0 400 kHz

Bus Free Time Between a STOP

and START Condition tBUF 1.3 Fs

Hold Time (Repeated) START

Condition tHD, STA 0.6 Fs

Repeated START Condition

Setup Time tSU, STA 0.6 Fs

STOP Condition Setup Time tSU, STO 0.6 Fs

4 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 2, 3)

Note 2: All parameters are tested at TA = +25NC. Specifications over temperature are guaranteed by design.

Note 3: All digital inputs at VCC or GND.

Note 4: Guaranteed by design.

Note 5: A master device must provide a hold time of at least 300ns for the SDA signal (referred to VIL of the SCL signal) to bridge

the undefined region of SCL’s falling edge.

Note 6: Cb = total capacitance of one bus line in pF. tR and tF measured between +0.3VCC and +0.7VCC.

Note 7: ISINK ≤ 6mA.

Note 8: Input filters on the SDA, SCL, and AD0 inputs suppress noise spikes less than 50ns.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Data Hold Time tHD, DAT (Note 5) 0.9 Fs

Data Setup Time tSU, DAT 100 ns

SCL Clock Low Period tLOW 1.3 Fs

SCL Clock High Period tHIGH 0.7 Fs

Rise Time of Both SDA and SCL

Signals, Receiving tR(Notes 4, 6) 20 +

0.1Cb300 ns

Fall Time of Both SDA and SCL

Signals, Receiving tF(Notes 4, 6) 20 +

0.1Cb300 ns

Fall Time of SDA Signal,

Transmitting tF, TX (Notes 4, 7) 20 +

0.1Cb250 ns

Pulse Width of Spike Suppressed tSP (Notes 4, 8) 50 ns

Capacitive Load for Each Bus

Line Cb(Note 4) 400 pF

5Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Typical Operating Characteristics

(VCC = +2.5V, TA = +25NC, unless otherwise noted.)

GPO OUTPUT LOW VOLTAGE

vs. SINK CURRENT (COL2–COL7)

MAX7360 toc01

SINK CURRENT (mA)

OUTPUT VOLTAGE (mV)

15105

100

150

200

250

TA = +85NC

TA = +25NC

TA = -40NC

VCC = 2.4V

GPO OUTPUT LOW VOLTAGE

vs. SINK CURRENT (COL2–COL7)

MAX7360 toc02

SINK CURRENT (mA)

OUTPUT VOLTAGE (mV)

15105

100

150

200

250

TA = +25°C

TA = -40°C

VCC = 3.0V

TA = +85°C

GPO OUTPUT LOW VOLTAGE

vs. SINK CURRENT (COL2–COL7)

MAX7360 toc03

SINK CURRENT (mA)

OUTPUT VOLTAGE (mV)

15105

100

150

200

250

TA = +25°C

TA = -40°C

VCC = 3.6V

TA = +85°C

KEY-SWITCH SOURCE CURRENT

vs. SUPPLY VOLTAGE

MAX7360 toc05

SUPPLY VOLTAGE (V)

KEY-SWITCH SOURCE CURRENT (A)

2.8

2.42.0

17.7

17.8

17.5

17.6

17.9

18.0

18.1

18.2

18.3

18.4

17.4

1.6 3.63.2

VCOL0 = O

TA = -40NC, +25NC

TA = +25NC

TA = -40NC

TA = -40NC, +85NC

TA = +85NC

SHUTDOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7360 toc06

SUPPLY VOLTAGE (V)

SHUTDOWN SUPPLY CURRENT (A)

2.8

2.42.0

1.0

0.5

1.5

2.0

2.5

3.0

1.6 3.63.2

TA = -40NC

TA = +25NC

TA = +85NC

CONSTANT-CURRENT GPIO OUTPUT

SINK CURRENT vs. OUTPUT VOLTAGE

MAX7360 toc07

OUTPUT VOLTAGE (V)

SINK CURRENT (mA)

1.5 2.01.00.5

0 3.02.5

TA = -40NC

VCC = 2.4V

TA = +25NC

TA = +85NC

CONSTANT-CURRENT GPIO OUTPUT

SINK CURRENT vs. OUTPUT VOLTAGE

MAX7360 toc09

OUTPUT VOLTAGE (V)

SINK CURRENT (mA)

1.5 2.01.00.5

0 3.02.5

TA = -40NC

VCC = 3.6V

TA = +25NC

TA = +85NC

CONSTANT-CURRENT GPIO OUTPUT

SINK CURRENT vs. OUTPUT VOLTAGE

MAX7360 toc08

OUTPUT VOLTAGE (V)

SINK CURRENT (mA)

1.5 2.01.00.5

0 3.02.5

25 VCC = 3.0V

TA = -40NC

TA = +25NC

TA = +85NC

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX7360 toc04

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (A)

2.8

2.4

2.0

1.6 3.6

3.2

TA = +85NC

AUTOSLEEP = OFF

TA = -40NC

TA = +25NC

6 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Pin Description

PIN NAME FUNCTION

TQFN WLP

1 A6 ROW0 Row Input from Key Matrix. Leave ROW0 unconnected or connect to GND if unused.

2 B6 ROW1 Row Input from Key Matrix. Leave ROW1 unconnected or connect to GND if unused.

3 C4 ROW2 Row Input from Key Matrix. Leave ROW2 unconnected or connect to GND if unused.

4 C6 ROW3 Row Input from Key Matrix. Leave ROW3 unconnected or connect to GND if unused.

5, 15, 25,

B4, C5, D2,

E4 GND Ground

6 D6 ROW4 Row Input from Key Matrix. Leave ROW4 unconnected or connect to GND if unused.

7 D5 ROW5 Row Input from Key Matrix. Leave ROW5 unconnected or connect to GND if unused.

8 E6 ROW6 Row Input from Key Matrix. Leave ROW6 unconnected or connect to GND if unused.

9 D4 ROW7 Row Input from Key Matrix. Leave ROW7 unconnected or connect to GND if unused.

10, 20, 27,

30, 40 C2 N.C. No Connection. Not internally connected. Leave unconnected.

11 F6 COL0 Column Output to Key Matrix. Leave COL0 unconnected if unused.

12 E5 COL1 Column Output to Key Matrix. Leave COL1 unconnected if unused.

13 F5 COL2 Column Output to Key Matrix. Leave COL2 unconnected if unused. COL2 can be

configured as a GPO (see Table 9 in the Register Tables section).

14 F4 COL3 Column Output to Key Matrix. Leave COL3 unconnected if unused. COL3 can be

configured as a GPO (see Table 9 in the Register Tables section).

16 F3 COL4 Column Output to Key Matrix. Leave COL4 unconnected if unused. COL4 can be

configured as a GPO (see Table 9 in the Register Tables section).

17 E3 COL5 Column Output to Key Matrix. Leave COL5 unconnected if unused. COL5 can be

configured as a GPO (see Table 9 in the Register Tables section).

18 F2 COL6 Column Output to Key Matrix. Leave COL6 unconnected if unused. COL6 can be

configured as a GPO (see Table 9 in the Register Tables section).

19 F1 COL7 Column Output to Key Matrix. Leave COL7 unconnected if unused. COL7 can be

configured as a GPO (see Table 9 in the Register Tables section).

21 E2 SDA I2C-Compatible, Serial-Data I/O

22 E1 SCL I2C-Compatible, Serial-Clock Input

23 D3 INTK Active-Low Key-Switch Interrupt Output. INTK is open drain and requires a pullup

resistor.

7Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Pin Description (continued)

PIN NAME FUNCTION

TQFN WLP

24 D1 INTI Active-Low GPI Interrupt Output. INTI is open drain and requires a pullup resistor.

26 C1 VCC Positive Supply Voltage. Bypass VCC to GND with a 0.1FF or higher ceramic capacitor.

28 B1 AD0 Address Input. AD0 selects up to four device slave addresses (Table 3).

29 A1 I.C. Internally Connected. Connect to GND for normal operation.

31 B2 PORT0 GPIO Port. Open-drain I/O rated at +14V. PORT0 can be configured as a constant-

current output.

32 A2 PORT1 GPIO Port. Open-drain I/O rated at +14V. PORT1 can be configured as a constant-

current output.

33 B3 PORT2 GPIO Port. Open-drain I/O rated at +14V. PORT2 can be configured as a constant-

current output.

34 A3 PORT3 GPIO Port. Open-drain I/O rated at +14V. PORT3 can be configured as a constant-

current output.

36 A4 PORT4 GPIO Port. Open-drain I/O rated at +14V. PORT4 can be configured as a constant-

current output.

37 C3 PORT5 GPIO Port. Open-drain I/O rated at +14V. PORT5 can be configured as a constant-

current output.

38 A5 PORT6 GPIO Port. Open-drain I/O rated at +14V. PORT6 can be configured as a constant-

current output, or a rotary switch input.

39 B5 PORT7 GPIO Port. Open-drain I/O rated at +14V. PORT7 can be configured as a constant-

current output, or a rotary switch input.

— — EP Exposed Pad (TQFN only). EP is internally connected to GND. Connect EP to a ground

plane to increase thermal performance.

8 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Functional Block Diagram

Detailed Description

The MAX7360 is a microprocessor peripheral low-noise

key-switch controller that monitors up to 64 key switches

with optional autorepeat, and key events that are pre-

sented in a 16-byte FIFO. The MAX7360 also features

eight open-drain GPIOs configured for digital I/O or

constant-current output for LED applications up to +14V.

The MAX7360 features an automatic sleep mode and

automatic wakeup that further reduce supply current

consumption. The MAX7360 can be configured to enter

sleep mode after a programmable time following a key

event. The FIFO content is maintained and can be read

in sleep mode. The MAX7360 does not enter autosleep

when a key is held down. The autowake feature takes

the MAX7360 out of sleep mode following a keypress

event. Enable/disable autosleep and autowake through

the configuration register (Table 8).

To prevent overloading the microprocessor with too

many interrupts, interrupt requests are issued on a

programmable number of FIFO entries, and/or after a

set period of time (Table 10). The key-switch status is

checked by reading the key-switch FIFO. A 1-byte read

access returns both the next key event in the FIFO (if

there is one) and the FIFO status. INTK functions as an

open-drain general-purpose output (GPO) capable of

driving an LED if key-switch interrupts are not required.

Up to six of the key-switch outputs function as open-

drain GPOs capable of driving additional LEDs when

the application requires fewer keys to be scanned. For

each key-switch output used as a GPO, the number of

monitored key switches reduces by eight.

Initial Power-Up

On power-up, all control registers are set to power-up

values and the MAX7360 is in sleep mode (Table 1).

128kHz

OSCILLATOR

POR

BUS

TIMEOUT

I2C

INTERFACE

CONTROL

REGISTERS

FIFO

KEY

SCAN

CURRENT

SOURCE

COLUMN

DRIVES

OPEN-

DRAIN

ROW

DRIVES

COLUMN ENABLE

GPO ENABLE

ROW ENABLE

CURRENT DETECT

COL0

COL1

COL2*

COL3*

COL4*

COL5*

COL6*

COL7*

PWM

GPIO

LOGIC

PORT GPIO

AND

CONSTANT-

CURRENT

LED DRIVE

LED ENABLE

GPIO ENABLE

GPIO INPUT

PORT0

PORT1

PORT2

PORT3

PORT4

PORT5

PORT6

PORT7

ROW0

ROW1

ROW2

ROW3

ROW4

ROW5

ROW6

ROW7

INTI

INTK

SDA

SCL

AD0

*GPO

MAX7360

ROTARY

9Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 1. Register Address Map and Power-Up Condition

ADDRESS

CODE

(hex)

READ/

WRITE

POWER-UP

VALUE (hex)

FUNCTION DESCRIPTION

0x00 Read only 0x3F Keys FIFO Read FIFO key-scan data out

0x01 R/W0x0A Configuration Power-down, key-release enable, autowakeup, and I2C time-

out enable

0x02 R/W0xFF Debounce Key debounce time settling and GPO enable

0x03 R/W0x00 Interrupt Key-switch interrupt INTK frequency setting

0x04 R/W0xFE GPO COL2–COL7 and INTK GPO control

0x05 R/W0x00 Key repeat Delay and frequency for key repeat

0x06 R/W0x07 Sleep Idle time to autosleep

0x40 R/W0x00 GPIO global con-

figuration Rotary switch, GPIO standby, GPIO reset, fade

0x41 R/W0x00 GPIO control PORT0–PORT7 input/output control

0x42 R/W0x00 GPIO debounce PORT0–PORT7 debounce time setting

0x43 R/W0xC0 GPIO constant-

current setting PORT0–PORT7 constant-current output setting

0x44 R/W0x00 GPIO output mode PORT0–PORT7 output mode control

0x45 R/W0x00 Common PWM Common PWM duty-cycle setting

0x46 R/W0x00 Rotary switch con-

figuration Rotary switch interrupt frequency and debounce time setting

0x48 Read only 0x00 I2C timeout flag I2C timeout since last POR

0x49 Read only 0xFF GPIO input register PORT0–PORT7 input values

0x4A Read only 0x00 Rotary switch count Switch cycles since last read

0x50 R/W0x00 PORT0 PWM PORT0 individual duty-cycle setting

0x51 R/W0x00 PORT1 PWM PORT1 individual duty-cycle setting

0x52 R/W0x00 PORT2 PWM PORT2 individual duty-cycle setting

0x53 R/W0x00 PORT3 PWM PORT3 individual duty-cycle setting

0x54 R/W0x00 PORT4 PWM PORT4 individual duty-cycle setting

0x55 R/W0x00 PORT5 PWM PORT5 individual duty-cycle setting

0x56 R/W0x00 PORT6 PWM PORT6 individual duty-cycle setting

0x57 R/W0x00 PORT7 PWM PORT7 individual duty-cycle setting

0x58 R/W0x00 PORT0 configuration PORT0 interrupt, PWM mode control and blink period setting

0x59 R/W0x00 PORT1 configuration PORT1 interrupt, PWM mode control and blink period setting

0x5A R/W0x00 PORT2 configuration PORT2 interrupt, PWM mode control and blink period setting

0x5B R/W0x00 PORT3 configuration PORT3 interrupt, PWM mode control and blink period setting

0x5C R/W0x00 PORT4 configuration PORT4 interrupt, PWM mode control and blink period setting

0x5D R/W0x00 PORT5 configuration PORT5 interrupt, PWM mode control and blink period setting

0x5E R/W0x00 PORT6 configuration PORT6 interrupt, PWM mode control and blink period setting

0x5F R/W0x00 PORT7 configuration PORT7 interrupt, PWM mode control and blink period setting

10 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Key-Scan Controller

Key inputs are scanned statically, not dynamically,

to ensure low-EMI operation. As inputs only toggle in

response to switch changes, the key matrix can be

routed closer to sensitive circuit nodes.

The key-scan controller debounces and maintains a FIFO

of keypress and release events (including autorepeated

keypresses, if autorepeat is enabled). Table 2 shows the

key-switch order. The user-programmable key-switch

debounce time, and autosleep timer, is derived from the

64kHz clock, which in turn is derived from the 128kHz

oscillator. Time delay for autorepeat and key-switch

interrupt is based on the key-switch debounce time.

Keys FIFO Register (0x00)

The keys FIFO register contains the information pertaining

to the status of the keys FIFO, as well as the key events

that have been debounced (see Table 7 in the Register

Tables section). Bits D0–D5 denote which of the 64 keys

have been debounced and the keys are numbered as in

Table 2.

D7 indicates if there is more data in the FIFO, except

when D5:D0 indicate key 63 or key 62. When D5:D0

indicate key 63 or key 62, the host should read one more

time to determine whether there is more data in the FIFO.

Use key 62 and key 63 for rarely used keys. D6 indicates

if it is a keypress or release event, except when D5:D0

indicate key 63 or key 62.

Reading the key-scan FIFO clears the interrupt INTK

depending on the setting of bit D5 in the configuration

Configuration Register (0x01)

The configuration register controls the I2C bus timeout

feature, enables key-release detection, enables autowake,

and determines how INTK is deasserted. Write to bit D7

to put the MAX7360 into sleep mode or operating mode.

Autosleep and autowake, when enabled, also change the

status of D7 (see Table 8 in the Register Tables section).

Debounce Register (0x02)

The debounce register sets the time for each debounce

cycle, as well as setting whether the GPO ports are

enabled or disabled. Bits D0–D4 set the debounce time

in increments of 1ms starting at 9ms and ending at 40ms

(see Table 9 in the Register Tables section). Bits D5, D6,

and D7 set which of the GPO ports is enabled. Note the

GPO ports are enabled only in the combinations shown

in Table 9, from all disabled to all enabled.

Key-Switch Interrupt Register (0x03)

The interrupt register contains information related to the

settings of the interrupt request function, as well as the

status of the INTK output, which can also be configured

as a GPO. If bits D0–D7 are set to 0x00, the INTK output

is configured as a GPO that is controlled by bit D1 in the

port register. There are two types of interrupts, the FIFO-

based interrupt and time-based interrupt. Set bits D0–D4

to assert interrupts at the end of the selected number of

debounce cycles following a key event (see Table 10 in

the Register Tables section). This number ranges from

1–31 debounce cycles. Setting bits D7, D6, and D5 set

the FIFO-based interrupt when there are 2–14 key events

stored in the FIFO. Both interrupts can be configured

simultaneously and INTK asserts depending on which

condition is met first. INTK deasserts depending on the

status of bit D5 in the configuration register.

Ports Register (0x04)

The ports register sets the values of PORT2–PORT7 and

the INTK port, when configured, as open-drain GPOs.

Table 2. Key-Switch Mapping

*These columns can be configured as GPOs.

PIN COL0 COL1 COL2* COL3* COL4* COL5* COL6* COL7*

ROW0 KEY 0 KEY 8 KEY 16 KEY 24 KEY 32 KEY 40 KEY 48 KEY 56

ROW1 KEY 1 KEY 9 KEY 17 KEY 25 KEY 33 KEY 41 KEY 49 KEY 57

ROW2 KEY 2 KEY 10 KEY 18 KEY 26 KEY 34 KEY 42 KEY 50 KEY 58

ROW3 KEY 3 KEY 11 KEY 19 KEY 27 KEY 35 KEY 43 KEY 51 KEY 59

ROW4 KEY 4 KEY 12 KEY 20 KEY 28 KEY 36 KEY 44 KEY 52 KEY 60

ROW5 KEY 5 KEY 13 KEY 21 KEY 29 KEY 37 KEY 45 KEY 53 KEY 61

ROW6 KEY 6 KEY 14 KEY 22 KEY 30 KEY 38 KEY 46 KEY 54 KEY 62

ROW7 KEY 7 KEY 15 KEY 23 KEY 31 KEY 39 KEY 47 KEY 55 KEY 63

11Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

The settings in this register are ignored for ports not con-

figured as GPOs, and a read from this register returns

the values stored in the register (see Table 11 in the

Autorepeat Register (0x05)

The MAX7360 autorepeat feature notifies the host that at

least one key has been pressed for a continuous period.

The autorepeat register enables or disables this feature,

sets the time delay after the last key event before the key

repeat code (0x7E) is entered into the FIFO, and sets the

frequency at which the key-repeat code is entered into

the FIFO thereafter. Bit D7 specifies whether the auto-

repeat function is enabled with 0 denoting autorepeat

disabled, and 1 denoting autorepeat enabled. Bits D0–

D3 specify the autorepeat delay in terms of debounce

cycles ranging from 8–128 debounce cycles (see Table

12 in the Register Tables section). Bits D4, D5, and D6

specify the autorepeat rate or frequency ranging from

4–32 debounce cycles.

When autorepeat is enabled, holding the key pressed

results in a key-repeat event that is denoted by 0x7E. The

key being pressed does not show up again in the FIFO.

Only one autorepeat code is entered into the FIFO,

regardless of the number of keys pressed. The auto-

repeat code continues to be entered in the FIFO at the

frequency set by bits D[4:6] until another key event is

recorded. Following the key-release event, if any keys

are still pressed, the MAX7360 restarts the autorepeat

sequence.

Autosleep Register (0x06)

Autosleep puts the MAX7360 in sleep mode to draw

minimal current. When enabled, the MAX7360 enters

sleep mode if no keys are pressed for the autosleep time

(see Table 13 in the Register Tables section).

Key-Switch Sleep Mode

In sleep mode, the MAX7360 draws minimal current.

Switch-matrix current sources are turned off and pulled

up to VCC. When autosleep is enabled, key-switch

inactivity for a period longer than the autosleep time

puts the part into sleep mode (FIFO data is maintained).

Writing a 1 to D7 in the configuration register, or a key-

press, can take the MAX7360 out of sleep mode. Bit D7

in the configuration register gives the sleep-mode status

and can be read any time. The FIFO data is maintained

while in sleep mode.

Autowake

Keypresses initiate autowake and the MAX7360 goes

into operating mode. Keypresses that autowake the

MAX7360 are not lost. When a key is pressed while the

MAX7360 is in sleep mode, all analog circuitry, including

switch-matrix current sources, turn on in 2ms. The initial

key needs to be pressed for 2ms plus the debounce time

to be stored in the FIFO. Write a 0 to D1 in the configura-

tion register (0x01) to disable autowakeup.

GPIOs

The MAX7360 has eight GPIO ports with LED control

functions. The ports can be used as logic inputs, logic

outputs, or constant-current PWM LED drivers. In addi-

tion, PORT7 and PORT6 can function as a rotary switch

input pair. When in PWM mode, the ports are set up

to start their PWM cycle in 45N phase increments. This

prevents large current spikes on the LED supply voltage

when driving multiple LEDs.

GPIO Global Configuration Register (0x40)

The GPIO global configuration register controls the main

settings for the eight GPIOs (see Table 14 in the Register

Tables section).

Bit D7 enables PORT[7:6] as inputs for a rotary switch.

Bit D5 enables interrupt generation for I2C timeouts. D4

is the main enable/shutdown bit for the GPIOs. D3 func-

tions as a software reset for the GPIO registers (0x40 to

0x5F). Bits D[2:0] set the fade in/out time for the GPIOs

configured as constant-current sinks.

GPIO Control Register (0x41)

The GPIO control register configures each port as either

an input or an output (see Table 15 in the Register Tables

section). All GPIOs allow individual configurations, and

power up as inputs. Enabling rotary switch mode auto-

matically sets D7 and D6 as inputs. The ports consume

additional current if their inputs are left undriven.

GPIO Debounce Configuration Register (0x42)

The GPIO debounce configuration register sets the

amount of time a GPIO must be held for the MAX7360

to register a logic transition (see Table 16 in the Register

Tables section). The GPIO debounce setting is inde-

pendent of the key-switch debounce setting. Five bits

(D[4:0]) set 32 possible debounce times from 9ms up

to 40ms.

12 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

GPIO Constant-Current Setting Register (0x43)

The GPIO constant-current setting register sets the global

constant-current amount (see Table 17 in the Register

Tables section). Bits D1 and D0 set the global current

values from 5mA up to 20mA.

GPIO Output Mode Register (0x44)

The GPIO output mode register sets an output as either

a constant-current or non-constant-current output for

PORT[7:0] (see Table 18 in the Register Tables section).

Outputs are configured as constant-current outputs by

default to prevent accidental loading of an LED across

an unregulated output. The constant-current circuits

automatically turn off when not in use to reduce current

consumption.

Common PWM Register (0x45)

The common PWM register stores the common constant-

current output PWM duty cycle (see Table 19 in the

translate over to a PWM duty cycle in the same manner

as the individual PWM registers (0x50 to 0x57). Ports can

use their own individual PWM value, or the common PWM

value. Write to this register to change the duty cycle of

several ports at once.

Rotary Switch Configuration Register (0x46)

The rotary switch configuration register stores rotary

switch settings for PORT7 and PORT6 (see Table 20 in

the Register Tables section). D7 determines whether

switch counts or a time delay will trigger an interrupt

if enabled. D[6:4] set the count or time amount to wait

before sending an interrupt. Bits D[3:0] set the debounce

cycle time for the rotary switch inputs. Debounce time

ranges from 0 to 15ms.

I2C Timeout Flag Register (0x48) (Read Only)

The I2C timeout flag register contains a single bit (D0),

which indicates if an I2C timeout has occurred (see Table

21 in the Register Tables section). Read this register to

clear an I2C timeout initiated interrupt.

GPIO Input Register (0x49) (Read Only)

The GPIO input register contains the input data for all of

the GPIOs (see Table 22 in the Register Tables section).

Ports configured as outputs are read as high. There is

one debounce period delay prior to detecting a transition

on the input port. This prevents a false interrupt from

occurring when changing a port from an output to an

input. The GPIO input register reports the state of all

input ports regardless of any interrupt mask settings.

Ports configured as an input have a 2FA internal pullup

to VCC for PORT[5:0] and a 10FA internal pullup to VCC

for PORT[7:6].

Rotary Switch Count Register (0x4A) (Read Only)

The MAX7360 keeps a count of the rotary switch rotations

in two’s compliment format (see Table 23 in the Register

Tables section). The register values wrap around as the

count value switches from a positive to a negative value

and back again. The count resets to zero after an I2C

read to this register.

PORT0–PORT7 Individual PWM Ratio Registers

(0x50 to 0x57)

Each port has an individual PWM ratio register (0x50 to

0x57, see Table 24 in the Register Tables section). Use

values 0x00 to 0xFE in these registers to configure the

number of cycles out of 256 the output sinks current

(LED is on), from 0 cycles to 254 cycles. Use 0xFF to

have an output continuously sink current (always on).

For applications requiring multiple ports to have the

same intensity, program a particular port’s configuration

(0x45). New PWM settings take place at the beginning of

a PWM cycle, to allow changes from common intensity to

individual intensity with no interruption in the PWM cycle.

PORT0–PORT7 Configuration Registers

(0x58 to 0x5F)

Registers 0x58 to 0x5F set individual configurations for

each port (see Table 25 in the Register Tables section).

Bits D7 and D6 determine the interrupt settings for the

inputs. Interrupts can assert upon detection of a logic

transition, a rising edge, or not at all. D5 sets the port’s

PWM setting to either the common or individual PWM

setting. Bits D[4:2] enable and set the ports’ individual

blink period from 0 to 4096ms. Bits D1 and D0 set a

port’s blink duty cycle.

Fading

Set the fade cycle time in the GPIO global configuration

Table 14 in the Register Tables section). Fade in increases

an LED’s PWM intensity in 16 even steps from zero to its

stored value. Fade out decreases an LED’s PWM intensity in

16 even steps from its current value to zero. Fading occurs

automatically in any of the following scenarios:

1) Change the common PWM register value from any

value to zero to cause all ports using the common

PWM register settings to fade out. No ports using

individual PWM settings are affected.

2) Change the common PWM register value to any

value from zero to cause all ports using the common

PWM register settings to fade in. No ports using indi-

vidual PWM settings are affected.

3) Put the part out of shutdown to cause all ports to fade

in. Changing an individual PWM intensity during fade

13Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

in automatically cancels that port’s fade and immedi-

ately output at its newly programmed intensity.

4) Put the part into shutdown to cause all ports to fade

out. Changing an individual PWM intensity during

fade out automatically cancels that port’s fade and

immediately turns off.

Blink

Each port has its own blink control settings through reg-

isters 0x58 to 0x5F (see Table 25 in the Register Tables

section). The blink period ranges from 0 (blink disabled)

to 4.096s. Settable blink duty cycles range from 6.25%

to 50%. All blink periods start at the same PWM cycle for

synchronized blinking between multiple ports.

GPIO Port Interrupts (INTI)

Three possible sources generate INTI: I2C timeout,

GPIOs configured as inputs, and the rotary switch

(registers 0x48, 0x49, and 0x4A). Read the respective

data/status registers for each type of interrupt to clear

INTI. Set register 0x46 for rotary switch-based interrupts.

Set registers 0x58 to 0x5F for individual GPI-based inter-

rupts. If multiple sources generate the interrupt, all the

related status registers must be read to clear INTI.

Rotary Switch

The MAX7360 can accept a 2-bit rotary switch inputs on

PORT6 and PORT7. Rotation of the switch in a clockwise

direction increments the count. Enable rotary switch

mode from the GPIO global configuration register (0x40).

Several settings for PORT6 and PORT7 occur during

rotary switch mode:

1) Each port has a 10FA pullup to VCC.

2) Register 0x46 sets the debounce time.

3) A debounced rising edge on PORT6 while PORT7 is

high decreases the count.

4) A debounced rising edge on PORT6 while PORT7 is

low increases the count.

For more details, see Figure 1.

Serial Interface

Figure 2 shows the 2-wire serial interface timing details.

Serial Addressing

The MAX7360 operates as a slave that sends and

receives data through an I2C-compatible 2-wire inter-

face. The interface uses a serial-data line (SDA) and

a serial-clock line (SCL) to achieve bidirectional com-

munication between master(s) and slave(s). A master

(typically a microcontroller) initiates all data transfers to

and from the MAX7360 and generates the SCL clock that

synchronizes the data transfer.

The MAX7360’s SDA line operates as both an input and

an open-drain output. A pullup resistor, typically 4.7kI,

Figure 2. 2-Wire Serial Interface Timing Details

Figure 1. Rotary Switch Input Signal Timing

SDA

SCL

tHD, STA

tLOW

tHIGH

tRtF

tSU, DAT tSU, STA

tSU, STO

tBUF

tHD, STA

tHD, DAT

START

CONDITION

STOP

CONDITION

START

CONDITION

REPEATED

START CONDITION

tF, TX

PORT7

PORT6

PORT7

PORT6

INCREMENT

DECREMENT

ROTARY SWITCH

DEBOUNCE

14 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

is required on SDA. The MAX7360’s SCL line operates

only as an input. A pullup resistor is required on SCL if

there are multiple masters on the 2-wire interface, or if

the master in a single-master system has an open-drain

SCL output.

Each transmission consists of a START (S) condition

(Figure 3) sent by a master, followed by the MAX7360

7-bit slave address plus R/W bit, a register address byte,

one or more data bytes, and finally, a STOP (P) condition.

START and STOP Conditions

Both SCL and SDA remain high when the interface is not

busy. A master signals the beginning of a transmission

with a START condition by transitioning SDA from high

to low while SCL is high. When the master has finished

communicating with the slave, it issues a STOP condition

by transitioning SDA from low to high while SCL is high.

The bus is then free for another transmission.

Bit Transfer

One data bit is transferred during each clock pulse

(Figure 4). The data on SDA must remain stable while

SCL is high.

Acknowledge

The acknowledge bit is a clocked 9th bit (Figure 5), which

the recipient uses to handshake receipt of each byte of

data. Thus, each byte transferred effectively requires

9 bits. The master generates the 9th clock pulse, and

the recipient pulls down SDA during the acknowledge

clock pulse; therefore, the SDA line is stable low during

the high period of the clock pulse. When the master is

transmitting to the MAX7360, the MAX7360 generates

the acknowledge bit because the MAX7360 is the recipi-

ent. When the MAX7360 is transmitting to the master,

the master generates the acknowledge bit because the

master is the recipient.

Figure 3. START and STOP Conditions

Figure 4. Bit Transfer

Table 3. 2-Wire Interface Address Map

PIN AD0 DEVICE ADDRESS

A7 A6 A5 A4 A3 A2 A1 A0

GND 0 1 1 1 0 0 0 R/W

VCC 0111010R/W

SDA 0 1 1 1 1 0 0 R/W

SCL 0 1 1 1 1 1 0 R/W

SDA

SCL

START

CONDITION

STOP

CONDITION

S P

SDA

SCL

DATA LINE STABLE;

DATA VALID

CHANGE OF DATA

ALLOWED

15Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Figure 5. Acknowledge

Figure 6. Slave Address

Slave Addresses

The MAX7360 has a 7-bit long slave address (Figure

6). The bit following a 7-bit slave address is the R/W bit,

which is low for a write command and high for a read

command.

The first 4 bits (MSBs) of the MAX7360 slave address

are always 0111. Slave address bits A3, A2, and A1

correspond, by the matrix in Table 3, to the states of the

device address input AD0, and A0 corresponds to the

R/W bit. The AD0 input can be connected to any of four

signals (GND, VCC, SDA, or SCL), giving four possible

slave address pairs and allowing up to four MAX7360

devices to share the bus. Because SDA and SCL are

dynamic signals, care must be taken to ensure that AD0

transitions no sooner than the signals on SDA and SCL.

The MAX7360 monitors the bus continuously, waiting for a

START condition, followed by its slave address. When the

MAX7360 recognizes its slave address, it acknowledges

and is then ready for continued communication.

Bus Timeout

The MAX7360 features a 20ms minimum bus timeout

on the 2-wire serial interface, largely to prevent the

MAX7360 from holding the SDA I/O low during a read

transaction should the SCL lock up for any reason before

a serial transaction is completed. Bus timeout operates

by causing the MAX7360 to internally terminate a serial

Figure 7. Command Byte Received

Figure 8. Command and Single Data Byte Received

SCL

SDA

TRANSMITTER

CLOCK PULSE FOR

ACKNOWLEDGE

START

CONDITION

SDA

RECEIVER

1 2 8 9

SDA

SCL

0 1 1 A3 A2 A11

MSB LSB

ACKR/W

S A A P0SLAVE ADDRESS COMMAND BYTE

D7 D6 D5 D4 D3 D2 D1 D0

COMMAND BYTE IS STORED ON RECEIPT OF

ACKNOWLEDGE CONDITION

ACKNOWLEDGE FROM MAX7360

R/W

S A A A P0SLAVE ADDRESS COMMAND BYTE DATA BYTE

1 BYTE

AUTOINCREMENT

COMMAND BYTE ADDRESS

D7 D6 D5 D4 D3 D2 D1 D0 D1 D0D3 D2D5 D4D7 D6

ACKNOWLEDGE FROM MAX7360 ACKNOWLEDGE FROM MAX7360

ACKNOWLEDGE FROM MAX7360

R/W

16 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

transaction, either read or write, if SCL low exceeds

20ms. After a bus timeout, the MAX7360 waits for a valid

START condition before responding to a consecutive

transmission. This feature can be enabled or disabled

under user control by writing to the configuration register

(Table 8 in the Register Tables section).

Message Format for Writing

the Key-Scan Controller

A write to the MAX7360 comprises the transmission of the

slave address with the R/W bit set to zero, followed by at

least 1 byte of information. The first byte of information

is the command byte. The command byte determines

which register of the MAX7360 is to be written by the next

byte, if received. If a STOP condition is detected after the

command byte is received, the MAX7360 takes no further

action (Figure 7) beyond storing the command byte.

Any bytes received after the command byte are data bytes.

The first data byte goes into the internal register of the

MAX7360 selected by the command byte (Figure 8).

If multiple data bytes are transmitted before a STOP condi-

tion is detected, these bytes are generally stored in subse-

quent MAX7360 internal registers, because the command

byte address generally autoincrements (Table 4).

Message Format for Reading

the Key-Scan Controller

The MAX7360 is read using the internally stored com-

mand byte as an address pointer, the same way the

stored command byte is used as an address pointer

for a write. The pointer generally autoincrements after

each data byte is read using the same rules as for a

write (Table 4). Thus, a read is initiated by first config-

uring the MAX7360’s command byte by performing a

write (Figure 7). The master can now read n consecutive

bytes from the MAX7360, with the first data byte being

read from the register addressed by the initialized com-

mand byte. When performing read-after-write verifica-

tion, remember to reset the command byte’s address,

because the stored command byte address is generally

autoincremented after the write (Figure 9, Table 4).

Operation with Multiple Masters

When the MAX7360 is operated on a 2-wire interface

with multiple masters, a master reading the MAX7360

uses a repeated start between the write that sets the

MAX7360’s address pointer, and the read(s) that takes

the data from the location(s). This is because it is pos-

sible for master 2 to take over the bus after master 1 has

set up the MAX7360’s address pointer, but before mas-

ter 1 has read the data. If master 2 subsequently resets

the MAX7360’s address pointer, master 1’s read can be

from an unexpected location.

Command Address Autoincrementing

Address autoincrementing allows the MAX7360 to be

configured with fewer transmissions by minimizing the

number of times the command address needs to be

sent. The command address stored in the MAX7360

generally increments after each data byte is written or

read (Table 4). Autoincrement only works when doing a

multiburst read or write.

Applications Information

Reset from I2C

After a catastrophic event such as ESD discharge or

microcontroller reset, use bit D7 of the configuration

state (the key-switch register values and FIFO remain

unaffected). Use bit D4 of the GPIO global configura-

tion register (0x40) as a software reset for the GPIOs.

Figure 9. N Data Bytes Received

Table 4. Autoincrement Rules

FUNCTION

ADDRESS

CODE (hex)

AUTOINCREMENT

ADDRESS (hex)

Keys FIFO 0x00 0x00

Autoshutdown 0x06 0x00

All other key switch 0x01 to 0x05 Addr + 0x01

All other GPIO 0x40 to 0x5F Addr + 0x01

S A A A P0SLAVE ADDRESS COMMAND BYTE DATA BYTE

N BYTES

AUTOINCREMENT

COMMAND BYTE ADDRESS

D7 D6 D5 D4 D3 D2 D1 D0 D1 D0D3 D2D5 D4D7 D6

ACKNOWLEDGE FROM MAX7360 ACKNOWLEDGE FROM MAX7360

ACKNOWLEDGE FROM MAX7360

R/W

17Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Figure 10. Ghost-Key Phenomenon Figure 11. Valid Three-Key Combinations

Ghost-Key Elimination

Ghost keys are a phenomenon inherent with key-switch

matrices. When three switches located at the corners

of a matrix rectangle are pressed simultaneously, the

switch that is located at the last corner of the rectangle

(the ghost key) also appears to be pressed. This occurs

because the potentials at the two sides of the ghost-key

switch are identical due to the other three connections—

the switch is electrically shorted by the combination of

the other three switches (Figure 10). Because the key

appears to be pressed electrically, it is impossible to

detect which of the four keys is the ghost key.

The MAX7360 employs a proprietary scheme that detects

any three-key combination that generates a fourth ghost

key, and does not report the third key that causes a

ghost-key event. This means that although ghost keys

are never reported, many combinations of three keys

are effectively ignored when pressed at the same time.

Applications requiring three-key combinations (such

as <Ctrl><Alt><Del>) must ensure that the three keys

are not wired in positions that define the vertices of a

rectangle (Figure 11). There is no limit on the number of

keys that can be pressed simultaneously as long as the

keys do not generate ghost-key events and FIFO is not full.

Low-EMI Operation

The MAX7360 uses two techniques to minimize EMI

radiating from the key-switch wiring. First, the voltage

across the switch matrix never exceeds +0.55V if not

in sleep mode, independent of supply voltage VCC.

This reduces the voltage swing at any node when a

switch is pressed to +0.55V maximum. Second, the keys

are not dynamically scanned, which would cause the

key-switch wiring to continuously radiate interference.

Instead, the keys are monitored for current draw (only

occurs when pressed), and debounce circuitry only

operates when one or more keys are actually pressed.

Switch On-Resistance

The MAX7360 is designed to be insensitive to resistance,

either in the key switches, or the switch routing to and

from the appropriate COL_ and ROW_ up to 4kI (max).

These controllers are therefore compatible with low-cost

membrane and conductive carbon switches.

Hot Insertion

The INTI, INTK, SCL, and AD0 inputs and SDA remain

high impedance with up to +3.6V asserted on them

when the MAX7360 powers down (VCC = 0). I/O ports

(PORT0–PORT7) remain high impedance with up to

+14V asserted on them when not powered. Use the

MAX7360 in hot-swap applications.

Staggered PWM

The LED’s on-time in each PWM cycle are phase

delayed 45N into eight evenly spaced start positions.

Optimize phasing when using fewer than eight ports as

constant-current outputs by allocating the ports with the

most appropriate start positions. For example, if using

four constant-current outputs, choose PORT0, PORT2,

PORT4, and PORT6 because their PWM start positions

are evenly spaced. In general, choose the ports that

spread the PWM start positions as evenly as possible.

This optimally spreads out the current demand from the

ports’ load supply.

INTK/INTI

There are two interrupt outputs, INTK and INTI. Each

interrupt operates independently from the other. See

the Key-Switch Interrupt Register (0x03) and the GPIO

Port Interrupts (INTI) sections for additional information

regarding these two interrupts.

Power-Supply Considerations

The MAX7360 operates with a +1.62V to +3.6V power-

supply voltage. Bypass the power supply to GND with a

0.1FF or higher ceramic capacitor as close as possible

to the device.

REGULAR KEYPRESS

EVENT

GHOST-KEY

EVENT

KEY-SWITCH MATRIX

KEY-SWITCH MATRIX KEY-SWITCH MATRIX

EXAMPLES OF VALID THREE-KEY COMBINATIONS

18 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

ESD Protection

All of the MAX7360 pins meet the 2kV Human Body

Model ESD tolerances. Key-switch inputs and GPIOs

meet IEC 61000-4-2 ESD protection. The IEC test

stresses consist of 10 consecutive ESD discharges per

polarity, at the maximum specified level and below (per

IEC 61000-4-2). Test criteria include:

1) The powered device does not latch up during the

ESD discharge event.

2) The device subsequently passes the final test used

for prescreening.

Tables 5 and 6 are from the IEC 61000-4-2: Edition 1.1

1999-05: Electromagnetic compatibility (EMC) Testing

and measurement techniques—Electrostatic discharge

immunity test.

Table 6. ESD Waveform Parameters

Table 5. ESD Test Levels

X = Open level. The level has to be specified in the dedicated

equipment specification. If higher voltages than those shown

are specified, special test equipment could be needed.

LEVEL

INDICATED

VOLTGE

(kV)

FIRST PEAK OF

CURRENT

DISCHARGE ±10%

(A)

RISE TIME (tr) WITH

DISCHARGE SWITCH

(ns)

CURRENT (±30%)

AT 30ns

(A)

CURRENT

(±30%) AT 60ns

(A)

1 2 7.5 0.7 to 1 4 2

2 4 15 0.7 to 1 8 4

3 6 22.5 0.7 to 1 12 6

4 8 30 0.7 to 1 16 8

1A—CONTACT

DISCHARGE 1B—AIR-GAP DISCHARGE

LEVEL TEST

VOLTAGE (kV) LEVEL TEST VOLTAGE

(kV)

1 2 1 2

2 4 2 4

3 6 3 8

4 8 4 10

X Special X Special

19Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 7. Keys FIFO Register Format (0x00)

SPECIAL FUNCTION KEYS FIFO REGISTER DATA

D7 D6 D5 D4 D3 D2 D1 D0

The key number indicated by D5:D0 is a key

event. D7 is always for a key press of key 62

and key 63. When D7 is 0, the key read is the

last data in the FIFO. When D7 is 1, there is

more data in the FIFO. When D6 is 1, key data

read from FIFO is a key release. When D6 is 0,

key data read from FIFO is a key press.

FIFO

empty

flag

Key

release

flag

X X X X X X

FIFO is empty. 0 0 1 1 1 1 1 1

FIFO is overflow. Continue to read data in FIFO 0 1 1 1 1 1 1 1

Key 63 is pressed. Read one more time to

determine whether there is more data in FIFO. 1 0 1 1 1 1 1 1

Key 63 is released. Read one more time to

determine whether there is more data in FIFO. 1 1 1 1 1 1 1 1

Key repeat. Indicates the last data in FIFO. 0 0 1 1 1 1 1 0

Key repeat. Indicates more data in FIFO. 0 1 1 1 1 1 1 0

Key 62 is pressed. Read one more time to

determine whether there is more data in FIFO. 1 0 1 1 1 1 1 0

Key 62 is released. Read one more time to

determine whether there is more data in FIFO. 1 1 1 1 1 1 1 0

20 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 8. Configuration Register Format (0x01)

Table 9. Debounce Register Format (0x02)

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 Sleep

(when 0x40

D4 = 1)

Key-switch operating mode. Key switches always remain active

when constant-current PWM is enabled (bit 4 of register 0x40 is

high) regardless of autosleep, autowakeup, or an I2C write to this bit.

(when 0x40

D4 = 0)

Key-switch sleep

mode. The entire

chip is shut down.

When constant-current PWM is disabled

(bit 4 of register 0x40 is low), I2C write,

autosleep, and autowakeup all can change

this bit. This bit can be read back by I2C

any time for current status.

(when 0x40

D4 = 0)

Key-switch operating

mode

D6 Reserved 0 — 0

D5 Interrupt

0INTK cleared when FIFO is empty

1INTK cleared after host read. In this mode, I2C should read the

FIFO until interrupt condition is removed or further INT may be lost.

D4 Reserved 0 — 0

D3 Key-release

enable

0Disable key releases 1

1Enable key releases

D2 Reserved 0 — 0

D1 Autowakeup

enable

0Disable keypress wakeup 1

1Enable keypress wakeup

D0 Timeout

disable

0I2C timeout enabled 0

1I2C timeout disabled

D7 D6 D5 D4 D3 D2 D1 D0

PORTS ENABLE DEBOUNCE TIME

Debounce time is 9ms X X X 0 0 0 0 0

Debounce time is 10ms X X X 0 0 0 0 1

Debounce time is 11ms X X X 0 0 0 1 0

Debounce time is 12ms X X X 0 0 0 1 1

Debounce time is 37ms X X X 1 1 1 0 0

Debounce time is 38ms X X X 1 1 1 0 1

Debounce time is 39ms X X X 1 1 1 1 0

Debounce time is 40ms X X X 1 1 1 1 1

GPO ports disabled (full key-scan functionality) 0 0 0 X X X X X

GPO port 7 enabled 0 0 1 X X X X X

GPO ports 7 and 6 enabled 0 1 0 X X X X X

21Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 10. Key-Switch Interrupt Register Format (0x03)

Table 9. Debounce Register Format (0x02) (continued)

D7 D6 D5 D4 D3 D2 D1 D0

PORTS ENABLE DEBOUNCE TIME

GPO ports 7, 6, and 5 enabled 0 1 1 X X X X X

GPO ports 7, 6, 5, and 4 enabled 1 0 0 X X X X X

GPO ports 7, 6, 5, 4, and 3 enabled 1 0 1 X X X X X

GPO ports 7, 6, 5, 4, 3, and 2 enabled 1 1 X X X X X X

Power-up default setting 1 1 1 1 1 1 1 1

D7 D6 D5 D4 D3 D2 D1 D0

FIFO-BASED INTK TIME-BASED INTK

INTK used as GPO 00000000

FIFO-based INTK disabled 000 Not all zero

INTK asserts every debounce cycle 00000001

INTK asserts every 2 debounce cycles 00000010

INTK asserts every 29 debounce cycles 00011101

INTK asserts every 30 debounce cycles 00011110

INTK asserts every 31 debounce cycles 00011111

Time-based INTK disabled Not all zero 00000

INTK asserts when FIFO has 4 key events 00100000

INTK asserts when FIFO has 6 key events 01000000

INTK asserts when FIFO has 8 key events 01100000

INTK asserts when FIFO has 14 key events 1110000 0

Both time-based and FIFO-based interrupts

active Not all zero Not all zero

Power-up default setting 00000000

22 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 11. Ports Register Format (0x04)

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 PORT 7 Control 0Clear port 7 low 1

1Set port 7 high (high impedance)

D6 PORT 6 Control 0Clear port 6 low 1

1Set port 6 high (high impedance)

D5 PORT 5 Control 0Clear port 5 low 1

1Set port 5 high (high impedance)

D4 PORT 4 Control 0Clear port 4 low 1

1Set port 4 high (high impedance)

D3 PORT 3 Control 0Clear port 3 low 1

1Set port 3 high (high impedance)

D2 PORT 2 Control 0Clear port 2 low 1

1Set port 2 high (high impedance)

D1 INTK Port Control 0Clear port INTK low 1

1Set port INTK high (high impedance)

D0 Reserved 0 — 0

23Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 12. Autorepeat Register Format (0x05)

D7 D6 D5 D4 D3 D2 D1 D0

ENABLE AUTOREPEAT RATE AUTOREPEAT DELAY

Autorepeat is disabled 0 X X X X X X X

Autorepeat is enabled 1AUTOREPEAT RATE AUTOREPEAT DELAY

Key-switch autorepeat delay is 8 debounce

cycles 1 X X X 0 0 0 0

Key-switch autorepeat delay is 16 debounce

cycles 1 X X X 0 0 0 1

Key-switch autorepeat delay is 24 debounce

cycles 1 X X X 0 0 1 0

Key-switch autorepeat delay is 112 debounce

cycles 1 X X X 1 1 0 1

Key-switch autorepeat delay is 120 debounce

cycles 1 X X X 1 1 1 0

Key-switch autorepeat delay is 128 debounce

cycles 1 X X X 1 1 1 1

Key-switch autorepeat frequency is 4

debounce cycles 1 0 0 0 X X X X

Key-switch autorepeat frequency is 8

debounce cycles 1 0 0 1 X X X X

Key-switch autorepeat frequency is 12

debounce cycles 1 0 1 0 X X X X

Key-switch autorepeat frequency is 32

debounce cycles 1 1 1 1 X X X X

Power-up default setting 00 0 0 0 0 0 0

24 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 13. Autosleep Register Format (0x06)

Table 14. GPIO Global Configuration Register (0x40)

AUTOSLEEP REGISTER RESERVED AUTOSHUTDOWN TIME

D7 D6 D5 D4 D3 D2 D1 D0

No Autosleep 00000000

Autosleep for (ms)

8192 0 0 0 0 0 0 0 1

4096 0 0 0 0 0 0 1 0

2048 0 0 0 0 0 0 1 1

1024 0 0 0 0 0 1 0 0

512 00000101

256 00000110

256 00000111

Power-up default settings 00000111

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 PORT6/PORT7

rotary switch

0PORT6/PORT7 operate as GPIOs 0

1PORT6/PORT7 operate as a rotary switch input

D6 Reserved 0 — 0

D5 I2C timeout

interrupt enable

0 Disabled

1INTI is asserted when I2C bus times out. INTI is deasserted when a

read is performed on the I2C timeout flag register (0x48).

D4 GPIO enable

PWM, constant-current circuits, and GPIs are shut down. GPO

values depend on their setting. Register 0x41 to 0x5F values are

stored and cannot be changed. The entire part is shut down if the

key switches are in sleep mode (D7 of register 0x01). 0

1Normal GPIO operation. PWM, constant-current circuits, and GPIOs

are enabled regardless of key-switch sleep mode state (see Table 8).

D3 GPIO reset

0Normal operation

Return all GPIO registers (registers 0x40 to 0x5F) to their POR

value. This bit is momentary and resets itself to 0 after the write

cycle.

D[2:0] Fade in/out time

000 No fading

000

XXX

PWM intensity ramps up (down) between the common PWM value

and 0% duty cycle in 16 steps over the following time period:

D[2:0] = 001 = 256ms

D[2:0] = 010 = 512ms

D[2:0] = 011 = 1024ms

D[2:0] = 100 = 2048ms

D[2:0] = 101 = 4096ms

D[2:0] = 110/111 = Undefined

25Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 15. GPIO Control Register (0x41)

Table 16. GPIO Debounce Configuration Register (0x42)

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 PORT7 0 Port is an input 0

1 Port is an output

D6 PORT6 0 Port is an input 0

1 Port is an output

D5 PORT5 0 Port is an input 0

1 Port is an output

D4 PORT4 0 Port is an input 0

1 Port is an output

D3 PORT3 0 Port is an input 0

1 Port is an output

D2 PORT2 0 Port is an input 0

1 Port is an output

D1 PORT1 0 Port is an input 0

1 Port is an output

D0 PORT0 0 Port is an input 0

1 Port is an output

D7 D6 D5 D4 D3 D2 D1 D0

RESERVED DEBOUNCE TIME

Power-up default setting

debounce time is 9ms 00000000

Debounce time is 10ms 00000001

Debounce time is 11ms 00000010

Debounce time is 12ms 00000011

Debounce time is 37ms 00011100

Debounce time is 38ms 00011101

Debounce time is 39ms 00011110

Debounce time is 40ms 00011111

26 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 17. GPIO Constant-Current Setting Register (0x43)

Table 18. GPIO Output Mode Register (0x44)

Table 19. Common PWM Register (0x45)

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D[7:6] Reserved 11 Set always as 11 11

D[5:2] Reserved 0000 — 0000

D[1:0] Constant-

current setting

00 Constant current is 5mA

01 Constant current is 6.67mA

10 Constant current is 10mA

11 Constant current is 20mA

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 PORT7 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D6 PORT6 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D5 PORT5 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D4 PORT4 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D3 PORT3 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D2 PORT2 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D1 PORT1 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D0 PORT0 0 Port is a constant-current open-drain output 0

1 Port is a non-constant-current open-drain output

D7 D6 D5 D4 D3 D2 D1 D0

COMMON PWM

Power-up default setting (common PWM

ratio is 0/256) 0 0 0 0 0 0 0 0

Common PWM ratio is 1/256 0 0 0 0 0 0 0 1

Common PWM ratio is 2/256 0 0 0 0 0 0 1 0

Common PWM ratio is 3/256 0 0 0 0 0 0 1 1

27Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 19. Common PWM Register (0x45) (continued)

Table 20. Rotary Switch Configuration Register (0x46)

D7 D6 D5 D4 D3 D2 D1 D0

INT

TYPE COUNTS/CYCLES DEBOUNCE CYCLE TIME

No debounce time X X X X 0 0 0 0

Debounce time is 1ms X X X X 0 0 0 1

Debounce time is 2ms X X X X 0 0 1 0

Debounce time is 3ms X X X X 0 0 1 1

Debounce time is 15ms X X X X 1 1 1 1

No interrupt generated by rotary switch X 0 0 0 X X X X

INTI asserted when rotary switch count = ±10 0 0 1 X X X X

INTI asserted when rotary switch count = ±20 0 1 0 X X X X

INTI asserted when rotary switch count = ±30 0 1 1 X X X X

INTI asserted when rotary switch count = ±70 1 1 1 X X X X

INTI asserted 25ms after first debounced event 1 0 0 1 X X X X

INTI asserted 50ms after first debounced event 1 0 1 0 X X X X

INTI asserted 75ms after first debounced event 1 0 1 1 X X X X

INTI asserted 175ms after first debounced event 1 1 1 1 X X X X

Power-up default setting 0 0 0 0 0 0 0 0

D7 D6 D5 D4 D3 D2 D1 D0

COMMON PWM

Common PWM ratio is 252/256 1 1 1 1 1 1 0 0

Common PWM ratio is 253/256 1 1 1 1 1 1 0 1

Common PWM ratio is 254/256 1 1 1 1 1 1 1 0

Common PWM ratio is 256/256

(100% duty cycle) 1 1 1 1 1 1 1 1

28 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 21. I2C Timeout Flag Register (0x48) (Read Only)

Table 22. GPIO Input Register (0x49) (Read Only)

Table 23. Rotary Switch Count Register (0x4A) (Read Only)

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D[7:1] Reserved 0000000 — 0000000

D0 I2C timeout flag

0No I2C timeout has occurred since last read or POR

I2C timeout has occurred since last read or POR. This bit is reset to

zero when a read is performed on this register. I2C timeouts must

be enabled for this function to work (see Table 8).

D7 D6 D5 D4 D3 D2 D1 D0

CYCLE COUNT

Cycle count in two’s complement (see the

Rotary Switch Configuration Register (0x46)

section)

X X X X X X X X

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 PORT7 0Port is input low 1

1Port is input high

D6 PORT6 0Port is input low 1

1Port is input high

D5 PORT5 0Port is input low 1

1Port is input high

D4 PORT4 0Port is input low 1

1Port is input high

D3 PORT3 0Port is input low 1

1Port is input high

D2 PORT2 0Port is input low 1

1Port is input high

D1 PORT1 0Port is input low 1

1Port is input high

D0 PORT0 0Port is input low 1

1Port is input high

29Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Table 24. PORT0–PORT7 Individual PWM Ratio Registers (0x50 to 0x57)

Table 25. PORT0–PORT7 Configuration Registers (0x58 to 0x5F)

D7 D6 D5 D4 D3 D2 D1 D0

PORT PWM

Power-up default setting (port PWM ratio is

0/256) 00000000

PORT PWM ratio is 1/256 00000001

PORT PWM ratio is 2/256 00000010

PORT PWM ratio is 3/256 00000011

PORT PWM ratio is 252/256 11111100

PORT PWM ratio is 253/256 11111101

PORT PWM ratio is 254/256 11111110

PORT PWM ratio is 256/256 (100% duty cycle) 11111111

BIT DESCRIPTION VALUE FUNCTION DEFAULT

VALUE

D7 Interrupt mask

0Interrupt is not masked

1Interrupt is masked. PORT7 interrupt mask is ignored when the

device is configured for rotary switch input.

D6 Edge/level

detect

0Rising edge-triggered

interrupts Interrupts only occur when the GPIO port

is configured as an input 0

1Rising or falling edge-

triggered interrupts

D5 Common PWM 0Port uses individual PWM intensity register to set the PWM ratio 0

1Port uses common PWM intensity register to set the PWM ratio

D[4:2] Blink period

000 Port does not blink

000

001 Port blink period is 256ms

010 Port blink period is 512ms

011 Port blink period is 1024ms

100 Port blink period is 2048ms

101 Port blink period is 4096ms

110/111 Undefined

D[1:0] Blink-on time

00 LED is on for 50% of the blink period

01 LED is on for 25% of the blink period

10 LED is on for 12.5% of the blink period

11 LED is on for 6.25% of the blink period

30 Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Pin Configurations

MAX7360

TQFN

TOP VIEW

ROW1

ROW3

GND

ROW4

ROW5

ROW0

N.C.

GND

INTI

AD0

I.C.

N.C.

INTK

SCL

1 2

PORT3

4 5 6 7

27282930 26

EP*

24 23 22

GND

PORT4

COL6

COL5

COL4

GND

ROW2

VCC

PORT5 COL3

PORT6

PORT7

N.C.

COL2

COL1

COL0

*EP = EXPOSED PAD, CONNECT EP TO GROUND.

PORT2

COL7

PORT1

20 N.C.

ROW6

ROW7

N.C. SDA

8 9 10

PORT0

MAX7360

TQFN

TOP VIEW

ROW1

ROW3

GND

ROW4

ROW5

ROW0

N.C.

GND

INTI

AD0

I.C.

N.C.

INTK

SCL

1 2

PORT3

4 5 6 7

27282930 26

EP*

24 23 22

GND

PORT4

COL6

COL5

COL4

GND

ROW2

VCC

PORT5 COL3

PORT6

PORT7

N.C.

COL2

COL1

COL0

*EP = EXPOSED PAD, CONNECT EP TO GROUND.

PORT2

COL7

PORT1

20 N.C.

ROW6

ROW7

N.C. SDA

8 9 10

PORT0

31Maxim Integrated

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Package Information

For the latest package outline information and land patterns (foot-

prints), go to www.maximintegrated.com/packages. Note that

a “+”, “#”, “-” in the package code indicates RoHS status only.

Package drawings may show a different suffix character, but the

drawing pertains to the package regardless of RoHS status.

Chip Information

PROCESS: BiCMOS

Typical Application Circuit

PACKAGE TYPE PACKAGE CODE DOCUMENT NO.

40 TQFN-EP T4055+1 21-0140

36 WLP W362A2+1 21-0301

PORT6

PORT7

PORT5

PORT4

PORT3

PORT2

PORT1

PORT0

MAX7360

ROW7

ROW6

ROW5

ROW4

ROW3

ROW2

ROW1

ROW0

SDA

SCL

INTI

INTK

AD0

COL0

COL1

COL2

COL3

COL4

COL5

COL6

COL7

GND

VCC

SCL

SDA

INTI

INTK

+1.8V

GND

µC

VCC

+14V

+3.3V

+14V

+3.3V

KEY 0

KEY 1

KEY 2

KEY 3

KEY 4

KEY 5

KEY 6

KEY 7

KEY 8

KEY 9

KEY 10

KEY 11

KEY 12

KEY 13

KEY 14

KEY 15

KEY 16

KEY 17

KEY 18

KEY 19

KEY 20

KEY 21

KEY 22

KEY 23

KEY 24

KEY 25

KEY 26

KEY 27

KEY 28

KEY 29

KEY 30

KEY 31

KEY 32

KEY 33

KEY 34

KEY 35

KEY 36

KEY 37

KEY 38

KEY 39

KEY 40

KEY 41

KEY 42

KEY 43

KEY 44

KEY 45

KEY 46

KEY 47

I2C-Interfaced Key-Switch Controller and LED

Driver/GPIOs with Integrated ESD Protection

MAX7360

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent

licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and

max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

32 Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 4/09 Initial release —

1 8/10 Updated Absolute Maximum Ratings and Notes 7 and 8 (now Notes 6 and 7) in

Electrical Characteristics 2, 3, 4

2 1/13 Added the Package Thermal Characteristics section; updated the DfOSC min and

max values in the Electrical Characteristics 2

Mouser Electronics

Authorized Distributor

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