MAX3221EEAE+ - Maxim Integrated

AVAILABLE

Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

UCSP is a trademark of Maxim Integrated Products, Inc.

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

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

General Description

The MAX3221E/MAX3223E/MAX3243E are 3V-powered

EIA/TIA-232 and V.28/V.24 communications interfaces

with automatic shutdown/wakeup features, high data-

rate capabilities, and enhanced electrostatic discharge

(ESD) protection. All transmitter outputs and receiver

inputs are protected to ±15kV using IEC 1000-4-2 Air-

Gap Discharge, to ±8kV using IEC 1000-4-2 Contact

Discharge, and to ±15kV using the Human Body Model.

The MAX3221E/MAX3223E/MAX3243E achieve a

1µA supply current with Maxim’s revolutionary

AutoShutdown™ feature. They save power without

changes to the existing BIOS or operating system by enter-

ing low-power shutdown mode when the RS-232 cable is

disconnected, or when the transmitters of the connected

peripherals are off.

The transceivers have a proprietary low-dropout trans-

mitter output stage, delivering true RS-232 performance

from a +3.0V to +5.5V supply with a dual charge pump.

The charge pump requires only four small 0.1µF capaci-

tors for operation from a +3.3V supply. Each device is

guaranteed to run at data rates of 250kbps while main-

taining RS-232 output levels.

The MAX3221E contains just one driver and one receiver,

making it the smallest single-supply RS-232 transceiver.

The MAX3223E has two drivers and two receivers. The

MAX3243E is a complete 3-driver/5-receiver serial port

ideal for notebook or subnotebook computers. It also

includes two noninverting receiver outputs that are always

active, allowing external devices to be monitored without

forward biasing the protection diodes in circuitry that may

be powered down.

The MAX3221E, MAX3223E, and MAX3243E are avail-

able in space-saving TQFN, SSOP, and TSSOP pack-

ages.

Applications

Notebook, Subnotebook, and Palmtop Computers

Cellular Phones

Battery-Powered Equipment

Handheld Equipment

Peripherals

Printers

Next Generation Device Features

oFor Space-Constrained Applications:

MAX3228E/MAX3229E: ±15kV ESD-Protected, +2.5V

to +5.5V RS-232 Transceivers in UCSP™

MAX3222E/MAX3232E/MAX3237E/MAX3241E/

MAX3246E: ±15kV ESD-Protected Down to 10nA,

+3.0V to +5.5V, Up to 1Mbps, True RS-232

Transceivers (MAX3246E Available in a UCSP

Package)

oFor Data Cable Applications:

MAX3380E/MAX3381E: +2.35V to +5.5V, 1µA,

2Tx/2Rx RS-232 Transceivers with ±15kV ESD-

Protected I/O and Logic Pins

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

AutoShutdown and UCSP are trademarks of Maxim Integrated Products, Inc.

†

Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; 5,649,210; and other patents pending.

Pin Configurations appear at end of data sheet.

Typical Operating Circuits appear at end of data sheet.

*Exposed pad.

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

denotes an automotive qualified part.

Ordering Information continued at end of data sheet.

Ordering Information

Selector Guide

PART

NO. OF

DRIVERS/

RECEIVERS

VCC

RANGE

(V)

AutoShutdown

MAX3221E 1/1 +3.0 to +5.5 

MAX3223E 2/2 +3.0 to +5.5 

MAX3243E 3/5 +3.0 to +5.5 

PART TEMP RANGE PIN-PACKAGE

MAX3221ECTE+ 0°C to +70°C 16 TQFN-EP*

MAX3221ECUE+ 0°C to +70°C 16 TSSOP

MAX3221ECAE+ 0°C to +70°C 16 SSOP

MAX3221EEAE+ -40°C to +85°C 16 SSOP

MAX3221EETE+ -40°C to +85°C 16 TQFN-EP*

MAX3221EEUE+ -40°C to +85°C 16 TSSOP

MAX3223ECPP+ 0°C to +70°C 20 PDIP

MAX3223ECAP+ 0°C to +70°C 20 SSOP

MAX3223ECUP+ 0°C to +70°C 20 TSSOP

MAX3223ECTP+ 0°C to +70°C 20 TQFN-EP*

MAX3223EEPP+ -40°C to +85°C 20 PDIP

MAX3223EEAP+ -40°C to +85°C 20 SSOP

MAX3223EEUP+ -40°C to +85°C 20 TSSOP

MAX3223EETP+ -40°C to +85°C 20 TQFN-EP*

MAX3223EEUP/V+ -40°C to +85°C 20 TSSOP

19-1283; Rev 7; 8/11

MAX3221E/

MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.)

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 +6V

V+ to GND (Note 1) ..................................................-0.3V to +7V

V- to GND (Note 1) ...................................................+0.3V to -7V

V+ + |V-|(Note 1) .................................................................+13V

Input Voltages

T_IN, EN, FORCEON, FORCEOFF to GND ............-0.3V to +6V

R_IN to GND ......................................................................±25V

Output Voltages

T_OUT to GND................................................................±13.2V

R_OUT, R2OUTB, INVALID to GND.........-0.3V to (VCC + 0.3V)

Short-Circuit Duration

T_OUT to GND .........................................................Continuous

Continuous Power Dissipation (TA= +70°C)

16-Pin SSOP (derate 7.14mW/°C above +70°C) ...........571mW

16-Pin TSSOP (derate 9.4mW/°C above +70°C) ........754.7mW

16-Pin TQFN (derate 20.8mW/°C above +70°C) ......1666.7mW

20-Pin Plastic DIP (derate 11.11mW/°C above +70°C)....889mW

20-Pin SSOP (derate 8.00mW/°C above +70°C) ...........640mW

20-Pin TSSOP (derate 10.9mW/°C above +70°C) .........879mW

20-Pin TQFN (derate 21.3mW/°C above +70°C) ......1702.1mW

28-Pin SSOP (derate 9.52mW/°C above +70°C)............762mW

28-Pin TSSOP (derate 12.8mW/°C above +70°C) .......1026mW

32-Pin TQFN (derate 37mW/°C above +70°C) ............2963mW

Operating Temperature Ranges

MAX32_ _EC_ _ ....................................................0°C to +70°C

MAX32_ _EE_ _..................................................-40°C to +85°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+300°C

Soldering Temperature (reflow) .......................................+260°C

Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.

VCC = 5.0V

RECEIVER OUTPUTS

AutoShutdown (FORCEON = GND, FORCEOFF = VCC)

LOGIC INPUTS

DC CHARACTERISTICS (VCC = 3.3V or 5.0V, TA= +25°C)

R_OUT receivers disabledOutput Leakage Current ±0.05 ±10 µA

Negative threshold

Positive threshold

Figure 5a

VCC = 3.3V

T_IN, EN, FORCEON,

FORCEOFF

CONDITIONS

IOUT = -1.0mA

IOUT = 1.6mA

Figure 5a

IOUT = -1.0mA

IOUT = 1.6mA

T_IN, EN, FORCEON, FORCEOFF

FORCEON = FORCEOFF = VCC,

no load

FORCEOFF = GND, all R_IN = GND

FORCEON = GND,

FORCEOFF = VCC, all R_IN open

VCC - 0.6 V

INVALID Output Voltage High

-0.3 0.3 V

Receiver Input Threshold to

INVALID Output Low

0.4 V

INVALID Output Voltage Low

-2.7 V

Receiver Input Threshold to

INVALID Output High

2.7

0.3 1 mA

Supply Current,

AutoShutdown Disabled

1.0 10 µASupply Current, Shutdown

Supply Current, AutoShutdown

2.0

PARAMETER MIN TYP MAX UNITS

Input Logic Threshold Low 0.8 V

1.0 10 µA

Input Logic Threshold High 2.4 V

Output Voltage Low 0.4 V

Output Voltage High VCC - 0.6 VCC - 0.1 V

SYMBOL

Transmitter Input Hysteresis 0.5 V

T_IN, EN, FORCEON, FORCEOFF

Input Leakage Current ±0.01 ±1 µA

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

ELECTRICAL CHARACTERISTICS (continued)

(VCC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER MIN TYP MAX UNITS

±25

Output Short-Circuit Current ±60 mA

Output Resistance 300 10M Ω

Output Leakage Current µA

Input Threshold Low 0.6 1.2 V

±5 ±5.4Output Voltage Swing V

CONDITIONS

VCC = V+ = V- = 0, TOUT = ±2V

VOUT = ±12V, VCC = 0 or 3V to

5.5V, transmitters disabled

All transmitter outputs loaded with

3kΩto ground

Receiver Positive or Negative

Threshold to INVALID High 1µsVCC = 5V, Figure 5b

Input Hysteresis 0.5 V

Input Threshold High V

Input Resistance 35 7kΩ

0.8 1.5

1.8 2.4

1.5 2.4

TA= +25°C

±5.0Transmitter Output Voltage V

T1IN = T2IN = GND, T3IN = VCC,

T3OUT loaded with 3kΩto GND,

T1OUT and T2OUT loaded with

2.5mA each

tINVH

SYMBOL

VCC = 3.3V

VCC = 5.0V

VCC = 3.3V

VCC = 5.0V

±15IEC 1000-4-2 Air-Gap Discharge

Receiver Positive or Negative

Threshold to INVALID Low 30 µsVCC = 5V, Figure 5btINVL

Input Voltage Range -25 25 V

Receiver or Transmitter Edge to

Transmitters Enabled 100 µsVCC = 5V, Figure 5btWU

Input Voltage Range -25 25 V

±8IEC 1000-4-2 Contact Discharge

R_IN, T_OUT

±15Human Body Model

RECEIVER INPUTS

TRANSMITTER OUTPUTS

MOUSE DRIVEABILITY (MAX3243E)

ESD PROTECTION

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

Typical Operating Characteristics

(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA = +25°C, unless otherwise noted.)

-6

-5

-4

-3

-2

-1

0 1000 2000 3000 4000 5000

MAX3221E/MAX3223E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3221E-01

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

VOUT+

T1 TRANSMITTING AT 250kbps

T2 (MAX3223E) TRANSMITTING AT 15.6kbps

VOUT-

0 1000 2000 3000 4000 5000

MAX3221E/MAX3223E

SLEW RATE vs. LOAD CAPACITANCE

MAX3221-TOC2

LOAD CAPACITANCE (pF)

SLEW RATE (V/µs)

-SLEW

+SLEW

FOR DATA RATES UP TO 250kbps

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

TIMING CHARACTERISTICS—MAX3221E/MAX3223E/MAX3243E

(VCC = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.)

Note 2: C1–C4 = 0.1µF, tested at 3.3V ±10%. C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%.

Note 3: Transmitter skew is measured at the transmitter zero cross points.

tPLH

RL= 3kΩ, CL= 1000pF,

one transmitter switching

tPHL

SYMBOL

⏐tPHL - tPLH ⏐

Receiver Output Disable Time ns

CONDITIONS

µs

0.15

Receiver Propagation Delay

CL= 150pF to

1000pF

kbps

UNITSMIN TYP MAXPARAMETER

(Note 3)

ns50Receiver Skew

ns100Transmitter Skew

VCC = 3.3V,

RL= 3kΩto 7kΩ,

TA= +25°C,

measured from +3V

to -3V or

-3V to +3V, one

transmitter switching

V/µsTransition-Region Slew Rate 630

CL= 150pF

250

0.15

Maximum Data Rate

nsNormal operationReceiver Output Enable Time

200Normal operation

200

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Typical Operating Characteristics (continued)

(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)

-6

-5

-4

-3

-2

-1

MAX3243E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224E-04

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

2000 30001000 4000 5000

1 TRANSMITTER AT 250kbps

2 TRANSMITTERS AT 15.6kbps

VOUT+

VOUT-

0 1000 2000 3000 4000 5000

MAX3243E

SLEW RATE vs. LOAD CAPACITANCE

MAX3243E-05

LOAD CAPACITANCE (pF)

SLEW RATE (V/µs)

0 20001000 3000 4000 5000

MAX3243E

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3243E-06

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

250kbps

120kbps

20kbps

T1 TRANSMITTING AT 250kbps

T2 (MAX3223E) TRANSMITTING AT 15.6kbps

0 20001000 3000 4000 5000

MAX3221E/MAX3223E

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224E-03

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

250kbps

120kbps

20kbps

T1 TRANSMITTING AT 250kbps

T2 (MAX3223E) TRANSMITTING AT 15.6kbps

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Pin Description

MAX3221E MAX3223E MAX3243E

TQFN-

SSOP/

TSSOP

TQFN-

DIP/

SSOP/

TSSOP

SO/

SSOP/

TSSOP

TQFN-

NAME FUNCTION

14 1 19 1 — 22 EN

Receiver Enable Control. Drive low for normal

operation. Drive high to force the receiver outputs

(R_OUT) into a high-impedance state.

16 2 1 2 28 28 C1+

Positive terminal of the voltage doubler Charge-Pump

Capacitor

15 3 20 3 27 27 V+ +5.5V generated by the charge pump

1 4 2 4 24 23 C1-

Negative terminal of the voltage doubler Charge-Pump

Capacitor

2 5 3 5 1 29 C2+ Positive terminal of inverting Charge-Pump Capacitor

3 6 4 6 2 30 C2- Negative terminal of inverting Charge-Pump Capacitor

4 7 5 7 3 31 V- -5.5V generated by the charge pump

5 8 7, 14 9, 16 4-8 1-5 R_IN RS-232 Receiver Inputs

6 9 8, 13 10, 15 15-19

13, 14,

15, 17,

R_OUT TTL/CMOS Receiver Outputs

7 10 9 11 21 — INVALID

Output of the Valid Signal Detector. INVALID is enabled

high if a valid RS-232 level is present on any receiver

input.

8 11 10, 11 12, 13 12, 13,

10, 11,

12 T_IN TTL/CMOS Transmitter Inputs

9 12 12 14 23 — FORCEON

Drive high to override automatic circuitry keeping

transmitters and charge pump on (FORCEOFF must be

high) (Table 1).

10 13 6, 15 8, 17 9, 10,

11 6, 7, 8 T_OUT RS-232 Transmitter Outputs

— — — — 20 19 R2OUTB

TTL/CMOS Noninverting Complementary Receiver

Output. Always active.

11 14 16 18 25 24 GND Ground

12 15 17 19 26 26 VCC +3.0V to +5.5V Supply Voltage

13 16 18 20 22 —

FORCEOF

Force-Off Input, active low. Drive low to shut down

transmitters, receivers (MAX3243E, except R2OUTB),

and on-board charge pump. This overrides all

automatic circuitry and FORCEON (Table 1).

— — — — — 21 SHDN Shutdown Control, Active Low

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

_______________Detailed Description

Dual Charge-Pump Voltage Converter

The MAX3221E/MAX3223E/MAX3243E’s internal power

supply consists of a regulated dual charge pump that

provides output voltages of +5.5V (doubling charge

pump) and -5.5V (inverting charge pump), over the

+3.0V to +5.5V VCC range. The charge pumps operate

in discontinuous mode: if the output voltages are less

than 5.5V, the charge pumps are enabled; if the output

voltages exceed 5.5V, the charge pumps are disabled.

Each charge pump requires a flying capacitor (C1, C2)

and a reservoir capacitor (C3, C4) to generate the V+

and V- supplies.

RS-232 Transmitters

The transmitters are inverting level translators that con-

vert CMOS-logic levels to 5.0V EIA/TIA-232 levels. They

guarantee a 250kbps data rate with worst-case loads

of 3kΩin parallel with 1000pF, providing compatibility

with PC-to-PC communication software such as

LapLink™. Transmitters can be paralleled to drive mul-

tiple receivers. The MAX3243E has been specifically

designed to drive serial mice. Figure 1 shows a com-

plete system connection. When FORCEOFF is driven to

ground, or the AutoShutdown circuitry senses invalid

voltage levels on all receiver inputs, the transmitters are

disabled and the outputs are forced into a high-imped-

ance state. When powered off or shut down, the output

can be driven up to ±12V. The transmitter inputs do not

have pull-up resistors.

Pin Description (continued)

MAX3221E MAX3223E MAX3243E

TQFN-

SSOP/

TSSOP

TQFN-

DIP/

SSOP/

TSSOP

SO/

SSOP/

TSSOP

TQFN-

EP NAME

FUNCTION

— — — — — 19, 20 R_OUTB

Noninverting Complementary Receiver Outputs.

Always active.

— — — — —

9, 16,

25, 32 N.C. No Connection. Not internally connected.

— — — — — — EP

Exposed Paddle (TQFN package only). Solder the exposed

paddle to the ground plane or leave unconnected.

MAX3243E

I/O

CHIP

WITH

UART

CPU

RS-232

POWER-

MANAGEMENT

UNIT OR

KEYBOARD

CONTROLLER

FORCEOFF

FORCEON

INVALID

Figure 1. Interface Under Control of PMU

LapLink is a trademark of Traveling Software.

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

RS-232 Receivers

The MAX3221E/MAX3223E/MAX3243E’s receivers con-

vert RS-232 signals to CMOS-logic output levels. All

receivers have inverting three-state outputs and can be

active or inactive. In shutdown (FORCEOFF = low) or in

AutoShutdown, the MAX3221E/MAX3223E’s receivers

are active (Table 1). Drive EN high to place the receiv-

er(s) in a high-impedance state. The MAX3243E’s

receivers are high-impedance when the part is in shut-

down (FORCEOFF = low).

The MAX3243E features an extra, always-active com-

plementary output (R2OUTB). R2OUTB monitors

receiver activity while the other receivers are high-

impedance. This allows Ring Indicator to be monitored

without forward biasing other devices connected to the

receiver outputs. This is ideal for systems where VCC

drops to 0 in shutdown to accommodate peripherals

such as UARTs (Figure 2).

The MAX3221E/MAX3223E/MAX3243E feature an

INVALID output that is enabled low when no valid RS-232

signal levels have been detected on all receiver inputs.

INVALID is functional in any mode (Figures 3 and 5).

AutoShutdown

The MAX3221E/MAX3223E/MAX3243E achieve a 1µA

supply current with Maxim’s new AutoShutdown fea-

ture, which operates when FORCEON is low and

FORCEOFF is high. When these devices sense no valid

signal levels on all receiver inputs for 30µs, the on-

board charge pump and drivers are shut off, reducing

supply current to 1µA. This occurs if the RS-232 cable

is disconnected or the connected peripheral transmit-

ters are turned off. The device turns on again when a

valid level is applied to any RS-232 receiver input. As a

result, the system saves power without changes to the

existing BIOS or operating system.

Table 2 and Figure 3c summarize the MAX3221E/

MAX3223E/MAX3243E operating modes. FORCEON

and FORCEOFF override AutoShutdown. When neither

control is asserted, the IC selects between these states

automatically, based on receiver input levels. Figures

3a, 3b, and 5a depict valid and invalid RS-232 receiver

levels. Figure 5 shows the input levels and timing dia-

gram for AutoShutdown operation.

MAX3243E

T1OUT

R2OUTB

5kΩ

UART

VCC

T1IN

THREE-STATED

LOGIC

TRANSITION

DETECTOR

R2IN

PROTECTION

DIODE

R2OUT

FORCEOFF = GND

VCC

µP

RS-232

UART

SHDN = GND

VCC

GND

5kΩ

a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE

RECEIVER OUTPUT IN SHUTDOWN.

b) NEW MAX3243E: IN SHUTDOWN, R2OUTB IS USED TO MONITOR EXTERNAL

DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT PATH

THROUGH THE UART'S PROTECTION DIODE.

GND

PROTECTION

DIODE

Figure 2. The MAX3243E detects RS-232 activity when the

UART and interface are shut down.

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Table 1. Output Control Truth Table

+0.3V

-0.3V

INVALID

TO MAX32_ _E

POWER SUPPLY

AND TRANSMITTERS

R_IN

* TRANSMITTERS ARE DISABLED, REDUCING SUPPLY CURRENT TO 1µA IF

ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30µs.

30µs

COUNTER

Figure 3a. MAX32_ _E Entering 1µA Supply Mode via

AutoShutdown

+2.7V

-2.7V

INVALID

TO MAX32_ _E

POWER SUPPLY

R_IN

*TRANSMITTERS ARE ENABLED IF:

ANY RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.

ANY RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30µs.

30µs

COUNTER

Figure 3b. MAX32_ _E with Transmitters Enabled Using

AutoShutdown

X = Don’t Care

A mouse or other system with AutoShutdown may need

time to wake up. Figure 4 shows a circuit that forces

the transmitters on for 100ms, allowing enough time for

the other system to realize that the MAX3221E/

MAX3223E/ MAX3243E are awake. If the other system

transmits valid RS-232 signals within that time, the RS-

232 ports on both systems remain enabled.

When shut down, the device’s charge pumps are off,

V+ is pulled to VCC, V- is pulled to ground, and the

transmitter outputs are high impedance. The time

required to exit shutdown is typically 100µs (Figure 5b).

Software-Controlled Shutdown

If direct software control is desired, INVALID can be

used to indicate DTR or Ring Indicator signal. Connect

FORCEOFF and FORCEON together to disable Auto-

Shutdown so the line acts like a SHDN input.

±15kV ESD Protection

As with all Maxim devices, ESD-protection structures are

incorporated on all pins to protect against electrostatic

discharges encountered during handling and assembly.

The driver outputs and receiver inputs of the

MAX3221E/MAX3223E/MAX3243E have extra protection

against static electricity. Maxim’s engineers have devel-

oped state-of-the-art structures to protect these pins

against ESD of ±15kV without damage. The ESD struc-

tures withstand high ESD in all states: normal operation,

shutdown, and powered down. After an ESD event,

Maxim’s E versions keep working without latchup,

whereas competing RS-232 products can latch and

must be powered down to remove latchup. See Table 4.

FORCEON

Active

R2OUTB

(MAX3243E)

Active

High-Z

R_OUT

(MAX3221E/

MAX3223E)

Active

High-Z

FORCEOFF

Active

High-Z

Active

T_OUT

High-Z

Active

High-Z

Active

R_OUT

(MAX3243E)

High-Z

Active

High-Z

0Yes

Normal Operation

(AutoShutdown) Yes

0 X

Normal Operation

(Forced On) X

Shutdown

(Forced Off) X

(MAX3221E/

MAX3223E)

VALID

RECEIVER

LEVEL

0 X

OPERATION

STATUS

0ActiveHigh-Z1High-Z Active

Shutdown

(AutoShutdown) No1

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

ESD protection can be tested in various ways; the trans-

mitter outputs and receiver inputs of this product family

are characterized for protection to the following limits:

1) ±15kV using the Human Body Model

2) ±8kV using the Contact Discharge Method specified

in IEC1000-4-2

3) ±15kV using IEC1000-4-2’s Air-Gap Method

EESSDD TTeesstt CCoonnddiittiioonnss

ESD performance depends on a variety of conditions.

Contact Maxim for a reliability report that documents

test setup, test methodology, and test results.

HHuummaann BBooddyy MMooddeell

Figure 6a shows the Human Body Model, and Figure

6b shows the current waveform it generates when dis-

charged into a low impedance. This model consists of a

100pF capacitor charged to the ESD voltage of interest,

which is then discharged into the test device through a

1.5kΩresistor.

IEC1000-4-2

The IEC1000-4-2 standard covers ESD testing and per-

formance of finished equipment; it does not specifically

refer to integrated circuits. The MAX3221E/ MAX3223E/

MAX3243E help you design equipment that meets

V-

VCC

V+

VCC

tINVL

tWU

INVALID

REGION

RECEIVER

INPUT

VOLTAGE

(V)

INVALID

OUTPUT

(V)

tINVH

TRANSMITTERS ENABLED, INVALID HIGH

RECEIVER INPUT LEVELS

AUTOSHUTDOWN, TRANSMITTERS DISABLED,

1µA SUPPLY CURRENT, INVALID LOW

TRANSMITTERS ENABLED, INVALID HIGH

-2.7V

-0.3V

+2.7V

+0.3V

INDETERMINATE

Figure 5. AutoShutdown Trip Levels

FORCEON

MASTER SHDN LINE

0.1µF1MΩ

FORCEOFF

MAX3221E

MAX3223E

MAX3243E

POWER-

MANAGEMENT

UNIT

Figure 4. AutoShutdown with Initial Turn-On to Wake Up a

Mouse or Another System

FORCEOFF POWER DOWN

INVALID

FORCEON

INVALID IS AN INTERNALLY GENERATED SIGNAL

THAT IS USED BY THE AUTOSHUTDOWN LOGIC

AND APPEARS AS AN OUTPUT OF THE DEVICE.

POWER DOWN IS ONLY AN INTERNAL SIGNAL.

IT CONTROLS THE OPERATIONAL STATUS OF

THE TRANSMITTERS AND THE POWER SUPPLIES.

Figure 3c. MAX32_ _E AutoShutdown Logic

Table 2. INVALID Truth Table

LowNo

HighYes

INVALID OUTPUT

RS-232 SIGNAL PRESENT

AT ANY RECEIVER INPUT

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Level 4 (the highest level) of IEC1000-4-2, without the

need for additional ESD-protection components.

The major difference between tests done using the

Human Body Model and IEC1000-4-2 is higher peak

current in IEC1000-4-2, because series resistance is

lower in the IEC1000-4-2 model. Hence, the ESD with-

stand voltage measured to IEC1000-4-2 is generally

lower than that measured using the Human Body

Model. Figure 7a shows the IEEE1000-4-2 model and

Figure 7b shows the current waveform for the ±8kV

IEC1000-4-2 Level 4 ESD contact-discharge test.

The air-gap test involves approaching the device with a

charged probe. The contact-discharge method connects

the probe to the device before the probe is energized.

Machine Model

The Machine Model for ESD tests all pins using a 200pF

storage capacitor and zero discharge resistance. Its

objective is to emulate the stress caused by contact that

occurs with handling and assembly during manufactur-

ing. Of course, all pins require this protection during

manufacturing, not just RS-232 inputs and outputs.

Therefore, after PC board assembly, the Machine Model

is less relevant to I/O ports.

___________Applications Information

Capacitor Selection

The capacitor type used for C1–C4 is not critical for

proper operation; either polarized or nonpolarized

capacitors may be used. The charge pump requires

0.1µF capacitors for 3.3V operation. For other supply

voltages, refer to Table 3 for required capacitor values.

Do not use values smaller than those listed in Table 3.

Increasing the capacitor values (e.g., by a factor of 2)

reduces ripple on the transmitter outputs and slightly

reduces power consumption. C2, C3, and C4 can be

increased without changing C1’s value. However, do

not increase C1 without also increasing the values of

C2, C3, and C4 to maintain the proper ratios (C1 to

the other capacitors).

CHARGE-CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

100pF

RC 1MΩRD 1500Ω

HIGH-

VOLTAGE

SOURCE

DEVICE

UNDER

TEST

CHARGE CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

STORAGE

CAPACITOR

150pF

RC 50MΩ to 100MΩRD 330Ω

HIGH-

VOLTAGE

SOURCE

DEVICE

UNDER

TEST

Figure 7a. IEC1000-4-2 ESD Test Model

tr = 0.7ns to 1ns

30ns

60ns

100%

90%

10%

IPEAK

Figure 7b. IEC1000-4-2 ESD Generator Current Waveform

Figure 6a. Human Body ESD Test Models

IP 100%

90%

36.8%

tRL TIME

tDL

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING

(NOT DRAWN TO SCALE)

10%

AMPERES

Figure 6b. Human Body Model Current Waveform

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

When using the minimum required capacitor values,

make sure the capacitor value does not degrade exces-

sively with temperature. If in doubt, use capacitors with a

larger nominal value. The capacitor’s equivalent series

resistance (ESR) usually rises at low temperatures and

influences the amount of ripple on V+ and V-.

Power-Supply Decoupling

In most circumstances, a 0.1µF VCC bypass capacitor is

adequate. In applications that are sensitive to power-

supply noise, use a capacitor of the same value as the

charge-pump capacitor C1. Connect bypass capacitors

as close to the IC as possible.

Transmitter Outputs

when Exiting Shutdown

Figure 8 shows two transmitter outputs when exiting

shut down mode. As they become active, the two trans-

mitter outputs are shown going to opposite RS-232 lev-

els (one transmitter output is high, the other is low).

Each transmitter is loaded with 3kΩin parallel with

1000pF. The transmitter outputs display no ringing or

undesirable transients as they come out of shutdown,

and are enabled only when the magnitude of V-

exceeds approximately -3V.

High Data Rates

The MAX3221E/MAX3223E/MAX3243E maintain the RS-

232 ±5.0V minimum transmitter output voltage even at

high data rates. Figure 9 shows a transmitter loopback

test circuit. Figure 10 shows a loopback test result at

120kbps, and Figure 11 shows the same test at 250kbps.

For Figure 10, all three transmitters were driven simulta-

neously at 120kbps into RS-232 loads in parallel with

1000pF. For Figure 11, a single transmitter was driven at

250kbps, and all three transmitters were loaded with an

RS-232 receiver in parallel with 1000pF.

Mouse Driveability (MAX3243E)

The MAX3243E has been specifically designed to power

serial mice while operating from low-voltage power sup-

plies. It has been tested with leading mouse brands such

as Logitech and Microsoft. When tested, the MAX3243E

successfully drove all serial mice and met their respective

current and voltage requirements. The MAX3243E’s regu-

lated dual charge pump ensures the transmitters will sup-

ply at least ±5V during worst-case conditions. Figure 12a

shows the transmitter outputs under increasing load cur-

rent. The AutoShutdown feature does not work with a

mouse, so FORCEOFF and FORCEON should be con-

nected to VCC. Figure 12b (on the following page) shows

a mouse driver test circuit. To achieve mouse driveability

with 1µA supply current when the port is inactive, use

parts with the AutoShutdown Plus™ feature (such as the

MAX3244E and MAX3245E).

0.330.0474.5 to 5.5

0.10.13.15 to 3.6

0.220.223.0 to 3.6

C2, C3, C4

(µF)

C1, CBYPASS

(µF)

VCC

(V)

Table 3. Required Capacitor Values

10.223.0 to 5.5

40µs/div

T2OUT

FORCEON =

FORCEOFF

T1OUT

5V/div

2V/div

VCC = 3.3V

C1–C4 = 0.1µF

Figure 8. Transmitter Outputs Exiting Shutdown or Powering Up

AutoShutdown Plus is a trademark of Maxim Integrated Products, Inc.

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Figure 9. Loopback Test Circuit

MAX3221E

MAX3223E

MAX3243E

5kΩ

R_ IN

R_ OUT

EN (MAX3221E/3E)

C2-

C2+

C1-

C1+

V-

V+

VCC

0.1µF

VCC

FORCEOFF

T_ OUT

T_ IN

GND

VCC

1000pF

2µs/div

T1IN

T1OUT

R1OUT

5V/div

VCC = 3.3V

Figure 10. Loopback Test Result at 120kbps

Table 4. ±15kV ESD-Protected, 3.0V to 5.5V Powered RS-232 Transceivers from Maxim

PART

SUPPLY

VOLTAGE

RANGE

(V)

NO.

Tx/Rx

GUARANTEED

DATA RATE

(kbps)

SUPPLY

CURRENT

(µA)

MAX3241E +3.0 to +5.5 3/5 250300

MAX3243E +3.0 to +5.5 3/5 2501

MAX3244E +3.0 to +5.5 3/5 2501

MAX3245E +3.0 to +5.5 3/5 1Mbps1

MAX3232E +3.0 to +5.5 2/2 250300

MAX3222E +3.0 to +5.5 2/2 250300

MAX3223E +3.0 to +5.5 2/2 2501

MAX3224E +3.0 to +5.5 2/2 2501

MAX3225E +3.0 to +5.5 2/2 1Mbps1

MAX3221E +3.0 to +5.5 1/1 2501

MAX3227E +3.0 to +5.5 1/1 1Mbps1

MAX3226E +3.0 to +5.5 1/1 2501

Auto-

Shutdown

Plus

—

Yes

—

Yes

—

Yes

Auto-

Shutdown

—

Yes

—

Yes

—

Yes

—

HUMAN

BODY

MODEL

(kV)

±15

IEC 1000-4-2

CONTACT

DISCHARGE

(kV)

±8

IEC 1000-4-2

AIR-GAP

DISCHARGE

(kV)

±15

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Figure 11. Loopback Test Result at 250kbps

2µs/div

T1IN

T1OUT

R1OUT

5V/div

VCC = 3.3V

Compatible with ACT and

HCT CMOS, and with TTL.

Incompatible with AC, HC,

or CD4000 CMOS.

3.35

SYSTEM

POWER-

SUPPLY

VOLTAGE

(V)

Compatible with all TTL and

CMOS-logic families.

Compatible with all CMOS

families.

3.33.3

COMPATIBILITY

VCC SUPPLY

VOLTAGE

(V)

Table 5. Logic Family Compatibility with

Various Supply Voltages

Figure 12a. Transmitter Output Voltage vs. Load Current per

Transmitter

-6

-5

-4

-3

-2

-1

012345678910

MAX2343E-FIG15

LOAD CURRENT PER TRANSMITTER (mA)

TRANSMITTER OUTPUT VOLTAGE (V)

VOUT+

VOUT-

VOUT+

VOUT-

VCC

VCC = 3.0V

___________________Chip Information

PROCESS: BiCMOS

Ordering Information (continued)

Interconnection with 3V and 5V Logic

The MAX3221E/MAX3223E/MAX3243E can directly

interface with various 5V logic families, including ACT

and xHCT CMOS. See Table 5 for more information on

possible combinations of interconnections.

*Exposed pad.

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

PART TEMP RANGE PIN-PACKAGE

MAX3243ECWI+ 0°C to +70°C 28 Wide SO

MAX3243ECAI+ 0°C to +70°C 28 SSOP

MAX3243ECUI+ 0°C to +70°C 28 TSSOP

MAX3243EEWI+ -40°C to +85°C 28 Wide SO

MAX3243EEAI+ -40°C to +85°C 28 SSOP

MAX3243EEUI+ -40°C to +85°C 28 TSSOP

MAX3243ECTJ+ 0°C to +70°C 32 TQFN-EP*

MAX3243EETJ+ -40°C to +85°C 32 TQFN-EP*

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

COMPUTER SERIAL PORT

-V

GND

SERIAL

MOUSE

MAX3243E

FORCEOFF

R5OUT

R4OUT

R3OUT

R2OUT

R1OUT

R2OUTB

LOGIC

OUTPUTS

5kΩ

R5IN 8

R4IN 7

R3IN 6

R2IN 5

R1IN 4

RS-232

INPUTS

GND

LOGIC

INPUTS

T3IN

T2IN

T1IN

C2-

C2+

C1-

C1+

T3OUT 11

T2OUT 10

T1OUT 9

V-

V+

VCC

0.1µF

0.1µF 26

0.1µF

FORCEON

INVALID

TO POWER-

MANAGEMENT

UNIT

+3.3V

Figure 12b. Mouse Driver Test Circuit

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Typical Operating Circuits

MAX3223E**

FORCEON

R2OUT10

R1OUT15

FORCEOFF 20

INVALID 11

R2IN 9

GND

RS-232

OUTPUTS

TTL/CMOS

INPUTS T2IN

T1IN

C2-

C2+

C1-

C1+

R1IN 16

T2OUT 8

T1OUT 17

V- 7

V+ 3

VCC

0.1µF

0.1µF 19

0.1µF

CBYPASS

+3.3V

RS-232

INPUTS

TO POWER-

MANAGEMENT

UNIT

TTL/CMOS

OUTPUTS 5kΩ

5kΩ

MAX3243E

FORCEOFF

R5OUT

R4OUT

R3OUT

R2OUT

R1OUT

R2OUTB

LOGIC

OUTPUTS

5kΩ

R5IN 8

R4IN 7

R3IN 6

R2IN 5

R1IN 4

RS-232

INPUTS

GND

RS-232

OUTPUTS

LOGIC

INPUTS

T3IN

T2IN

T1IN

C2-

C2+

C1-

C1+

T3OUT 11

T2OUT 10

T1OUT 9

V- 3

V+ 27

VCC

CBYPASS

VCC

0.1µF

0.1µF 26

0.1µF

FORCEON

INVALID

TO POWER-

MANAGEMENT UNIT

+3.3V

MAX3221E*

FORCEON

R1OUT9

FORCEOFF 16

INVALID 10

GND

T1IN

C2-

C2+

C1-

C1+

R1IN 8

T1OUT 13

V- 7

V+ 3

VCC

0.1µF

0.1µF 15

0.1µF

CBYPASS

+3.3V

TO POWER-

MANAGEMENT

UNIT

5kΩ

*MAX3221E PIN OUT REFERS TO SSOP/TSSOP PACKAGES.

**MAX3223E PIN OUT REFERS TO DIP/SSOP/TSSOP PACKAGES.

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Pin Configurations

FORCEOFF

VCC

GND

T1OUT

C1-

V+

C1+

R1IN

R1OUT

FORCEON

T1IN

T2OUT

V-

C2-

C2+

T2IN

INVALID

R2OUT

R2IN

DIP/SSOP/TSSOP

MAX3223E

*CONNECT EP TO GND OR LEAVE UNCONNECTED

C1+

V+

VCC

GND

C1-

FORCEON

FORCEOFF

INVALID

R2OUTB

R1OUT

R2OUT

R3OUT

R4OUT

R5OUT

C2+

C2-

V-

R1IN

R2IN

R3IN

R4IN

R5IN

T1OUT

T2OUT

T3OUT

T3IN

T2IN

T1IN

SO/SSOP/TSSOP

MAX3243E

TOP VIEW

C1+

V+

C1-

C2+

C2-

V-

R1IN

FORCEOFF

VCC

GND

T1OUT

FORCEON

T1IN

INVALID

R1OUT

MAX3221E

SSOP/TSSOP

TQFN-EP

N.C.

V-

C2-

C2+

C1+

V+

VCC

N.C.

T3IN

T2IN

T1IN

R5OUT

R4OUT

R3OUT

16 N.C.

17181920212223

R2OUT

R1OUT

R2OUTB

R1OUTB

SHDN

C1-

8765432

T3OUT

T2OUT

T1OUT

R5IN

R4IN

R3IN

R2IN

MAX3243E

R1IN

GND

TOP VIEW

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Pin Configurations (continued)

C2+

V-

C1-

GND

FORCEON

VCC

12 11 9

V+

C1+

T1IN

INVALID

R1OUT

R1IN

MAX3221E*

C2- T1OUT

FORCEOFF

TQFN

*CONNECT EP TO GND OR LEAVE UNCONNECTED

TOP VIEW

MAX3223E*

TQFN

C1-

C2-

V-

C1+

R1IN

FORCEON

T1IN

T1OUT

FORCEOFF

15 14 12 11

V+

*CONNECT EP TO GND OR LEAVE UNCONNECTED

INVALID

R2OUT

R2IN

T2OUT

C2+ R1OUT

VCC

16 10 T2IN

GND

Package Information

For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or

“-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing per-

tains to the package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND

PATTERN NO.

16 TQFN-EP T1655+2 21-0140 90-0072

16 SSOP A16+2 21-0056 90-0106

16 TSSOP U16+1 21-0066 90-0117

20 TQFN-EP T2055+5 21-0140 90-0010

20 SSOP A20+2 21-0056 90-0094

20 TSSOP U20+2 21-0066 90-0116

20 PDIP P20+3 21-0043 —

28 Wide SO W28+6 21-0042 90-0109

28 SSOP A28+1 21-0056 90-0095

28 TSSOP U28+2 21-0066 90-0171

32 TQFN-EP T3277+2 21-0144 90-0125

Maxim Integrated

MAX3221E/MAX3223E/MAX3243E

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

7 8/11 Added MAX3223EEUP/V+ automotive qualified part and updated Ordering

Information to show lead-free versions 1, 2, 14, 17, 18

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

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

Maxim 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.

MAX3221E/MAX3223E/MAX3243E

±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,

RS-232 Transceivers with AutoShutdown

Mouser Electronics

Authorized Distributor

Click to View Pricing, Inventory, Delivery & Lifecycle Information:

Maxim Integrated:

MAX3221ECAE+ MAX3221ECTE+ MAX3221EEAE+ MAX3223ECAP+ MAX3223ECUP+ MAX3223EEAP+

MAX3223EEPP+ MAX3223EETP+ MAX3223EEUP+ MAX3243ECAI+ MAX3243ECUI+ MAX3243EEAI+

MAX3243EEUI+ MAX3221EEAE+G071 MAX3223EEAP+G071 MAX3243EEAI+G071 MAX3221EEAE+TG071

MAX3223EEAP+TG071 MAX3243EEAI+TG071 MAX3223EEAP-T MAX3221ECAE+T MAX3221ECTE+T

MAX3221ECUE+ MAX3221ECUE+T MAX3221EEAE MAX3221EEAE+T MAX3221EEAE-T MAX3221EETE+

MAX3221EETE+T MAX3221EEUE+ MAX3221EEUE+T MAX3223ECAP+T MAX3223ECPP+ MAX3223ECTP+

MAX3223ECTP+T MAX3223ECUP+T MAX3223EEAP MAX3223EEAP+T MAX3223EETP+T MAX3223EEUP+T

MAX3243ECAI+T MAX3243ECUI+T MAX3243ECWI+ MAX3243ECWI+T MAX3243EEAI+T MAX3243EEUI+T

MAX3243EEWI+ MAX3243EEWI+T MAX3221EEAE/GG8-T MAX3202EEWS+T MAX3243EETJ+