General Description
The MAX6946 evaluation (EV) kit is an assembled and
tested PCB that demonstrates the capabilities of the
MAX6946 constant-current LED driver and digital I/O
expander. The EV kit includes three RGB LEDs and one
white LED that can be controlled simultaneously by the
MAX6946. The MAX6947 can also be evaluated on the
EV kit board by replacing the MAX6946 IC.
The MAX6946 evaluation system (EV system) includes
a MAX6946 EV kit and a Maxim interface board
(CMAXQUSB). The CMAXQUSB board connects to a
PC’s USB port and allows the transfer of I2C commands
to the MAX6946 EV kit.
The CMAXQUSB board allows a PC to use its USB port to
emulate an I2C 2-wire interface. Windows®
98SE/2000/XP-compatible software (which can be
downloaded from www.maxim-ic.com/evkitsoftware) pro-
vides a user-friendly interface to exercise the fea-
tures of the MAX6946. The program is menu driven and
offers a graphical user interface (GUI) with control buttons
and a status display. Order the MAX6946EVCMAXQU+
for a complete PC-based evaluation kit of the MAX6946.
Order the MAX6946EVKIT+ if you already have a
CMAXQUSB interface board or an I2C-compatible 2-wire
interface system.
Features
♦Proven PCB Layout
♦Windows 98SE/2000/XP-Compatible Evaluation
Software
♦Three RGB LEDs and One White LED
♦Access to I2C Interface Signals
♦Header for Accessing to the MAX6946 10 I/O Ports
♦Fully Assembled and Tested
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
________________________________________________________________
Maxim Integrated Products
1
19-0752; Rev 0; 2/07
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Ordering Information
PART T EM P
R A N G E*
IC
PACKAGE
2 - W IR E
SER IA L
I N T ER F A C E
T YPE
MAX6946EVKIT+ 0°C to
+70°C 16 TQFN-EP
User-
supplied I2C
interface
M A X6 9 4 6 EVC M A XQ U + 0°C to
+70°C 16 TQFN-EP
CMAXQUSB
interface
board
Component List
PART QTY DESCRIPTION
MAX6946EVKIT+ 1 MAX6946 EV kit
CMAXQUSB+ 1 Maxim interface board
Windows is a registered trademark of Microsoft Corp.
+
Denotes a lead-free and RoHS-compliant EV kit/system.
*
PCB temperature rating only.
MAX6946EVCMAXQU EV System
DESIGNATION QTY DESCRIPTION
C1 1
0.1µF ±10%, 6.3V X5R ceramic
capacitor (0402)
TDK C1005X5R0J104K
C2 0 Not installed, ceramic capacitor
(0603)
C3 1
10µF ±10%, 10V X5R ceramic
capacitor (0805)
TDK C2012X5R1A106K
MAX6946 Evaluation Kit
DESIGNATION QTY DESCRIPTION
C4 0 Not installed, ceramic capacitor
(0805)
D1, D2, D3 3 RGB LEDs (2.4mm x 3.2mm)
Optek OVSARGB3R8
D4 1 White LED (PLCC-2)
Optek OVS9WBCR9
J1 1 2 x 10 right-angle female receptacle
J2 1 2 x 10-pin header
JU1 1 2-pin header
JU2 0 Not installed, 3-pin header
R1 1 4.7kΩ ±5% resistor (0402)
R2–R11 0 Not installed, resistors (0402)
R12, R13 0 Not installed, resistors (0603)
MAX6946 Evaluation Kit
Component Suppliers
SUPPLIER PHONE WEBSITE
Optek 972-323-2200 www.optekinc.com
TDK 847-803-6100 www.component.tdk.com
Note: Indicate you are using the MAX6946/MAX6947 when
contacting these manufacturers.
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
2 _______________________________________________________________________________________
Quick Start
Recommended Equipment
• The Maxim MAX6946EVCMAXQU evaluation system:
MAX6946 EV kit
Maxim interface board (CMAXQUSB)
USB cable (included with CMAXQUSB)
• One 5.5V to 7.0V, 300mA power supply
• One user-supplied Windows 98SE/2000/XP PC with
an unused USB port
Note: In the following section(s), software-related items
are identified by bolding. Text in bold refers to items
directly from the EV kit software. Text in bold and
underline refers to items from the Windows
98SE/2000/XP operating system.
Procedure
The MAX6946 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below to verify
board operation. Do not enable the power supply until
all connections are made.
1) Visit the Maxim Integrated Products website
(www.maxim-ic.com/evkitsoftware) to download the
most current version of the EV kit software
MAX6946Rxx.ZIP. Save the EV kit software to a tem-
porary folder and uncompress the ZIP file.
2) Install the MAX6946 EV kit software on your PC by
running the INSTALL.EXE program. The program
files are copied and icons are created for them in
the Windows Start | Programs menu.
3) Place a shunt on the 3.3V setting of jumper JU1 on
the CMAXQUSB interface board.
4) Verify that the two switches on SW1, located on the
CMAXQUSB board, are set to the ON position.
5) Verify that a shunt is installed across jumper JU1 on
the EV kit board.
6) Connect the MAX6946 EV kit’s 20-pin female con-
nector (J1) to the CMAXQUSB’s 20-pin male con-
nector (P3).
7) Connect the 5.5V power supply between the
MAX6946 EV kit’s VLED and GND pads.
8) Enable the power supply.
9) Connect the USB cable from the PC to the
CMAXQUSB board. A Building Driver Database
window should pop up in addition to a New
Hardware Found message if this is the first time the
EV kit board is connected to the PC. If you do not
see a window that is similar to the one described
above after 30 seconds, try removing the USB
cable from the CMAXQUSB and reconnect it.
Administrator privileges are required to install the
USB device driver on Windows 2000 and XP. Refer
to the document TROUBLESHOOTING_USB.PDF
included with the software if you have any problems
during this step.
10) Follow the directions of the Add New Hardware
Wizard to install the USB device driver. Choose the
Search for the best driver for your device option.
Specify the location of the device driver to be
C:\Program Files\MAX6946 (default installation
directory) using the Browse button.
11) Start the MAX6946 EV kit software by opening its icon
in the Start | Programs menu. The application win-
dow shown in Figure 1 appears, and the software
connects to the CMAXQUSB after a few seconds.
12) Select the Run Enable: drop box located in the
Global Settings group box and select Run Mode.
13) Select the Constant-Current Sink radio button in
the P0-P9 Configuration group box to illuminate all
of the LEDs on the EV kit.
DESIGNATION QTY DESCRIPTION
SW1 1 Momentary pushbutton switch
U1 1
Maxim: MAX6946ATE+ (16-pin
TQFN 3mm x 3mm)
Top Mark: AES
See jumper
table for
jumper settings
11 Shunts (J2, JU1)
— 1 PC Board: MAX6946 Evaluation Kit
MAX6946 Evaluation Kit
FILE DESCRIPTION
INSTALL.EXE Installs the EV kit files on
your computer
MAX6946.EXE Executes the application
program
UNINST.INI Uninstalls the EV kit
software
Ftd2xx.INF USB device driver file
TROUBLESHOOTING_USB.PDF USB troubleshooting guide
MAX6946EVKIT Files
Component List (continued)
Detailed Description of
Hardware
MAX6946 EV System
The MAX6946 EV system (MAX6946EVCMAXQU) is a
complete 10-port, constant-current LED driver and I/O
expander system, consisting of a MAX6946 EV kit and
the Maxim interface board (CMAXQUSB).
CMAXQUSB
The CMAXQUSB is a Maxim interface board that pro-
vides an I2C interface bus to demonstrate various
Maxim devices. Maxim reserves the right to change the
implementation of this module at any time with no
advance notice.
MAX6946 EV Kit
The MAX6946 EV kit board provides a proven layout for
evaluating the MAX6946 constant-current LED dri-
ver/10-port I/O expander IC and can be obtained sepa-
rately without the CMAXQUSB. The 10 I/O ports can be
configured as logic inputs, open-drain logic outputs,
constant-current sink outputs, or any combination of the
above. The EV kit includes three RGB LEDs (D1, D2,
and D3) and one white LED (D4). These LEDs can be
enabled and the current through each LED can be con-
trolled using the MAX6946 EV kit software (see the
Detailed Description of Software
section).
The MAX6946 EV kit includes PCB pads (R2–R11) on the
bottom side of the PCB that can be used to add pullup
resistors at each of the MAX6946’s P0–P9 ports to oper-
ate the EV kit in logic input/output mode.
Power Supplies
The MAX6946 EV kit requires a 2.25V to 3.6V power
supply connected to the VDD and GND PC pads for
normal operation. The EV kit can also use the
CMAXQUSB interface board’s 3.3V power source by
installing a shunt across jumper JU1 on the MAX6946
EV kit and configuring the CMAXQUSB interface board
VDD. Set jumper JU1 in the CMAXQUSB to 3.3V. See
Table 1 for EV kit jumper JU1 configuration. Note:
Insure that all of the data sheet absolute maximum
specifications are not violated when operating the
MAX6946 EV kit.
The EV kit also requires a 5.5V to 7V voltage source
connected to the VLED and GND pads to power the
LEDs when operating the EV kit in input/current-sink
mode. Use voltages from 2.25V to 7V to provide a
pullup voltage during logic output/input operation.
RST
Input
The EV kit features a pushbutton switch, SW1, that con-
nects the MAX6946 RST pin to ground. Push and hold
the pushbutton switch to connect the RST pin to
ground. Refer to the
RST Input
section in the MAX6946/
MAX6947 IC data sheet to use this RST feature.
I/O Ports
The MAX6946 EV kit includes three RGB LEDs (D1, D2,
and D3) and one white LED (D4) connected to the 10 I/O
ports through shunts installed on header J2. The LEDs
are enabled by configuring the respective port on the
MAX6946 to constant-current static output, constant-cur-
rent PWM output, or low-logic output mode. For logic
operation at each port, remove the shunts on header J2,
install 10kΩpullup resistors on PC pads R2–R11, and
configure the ports for logic outputs or inputs.
I2C Clock and Data Inputs
The MAX6946 EV kit features a 2 x 10 right-angle header
receptacle (J1) to interface with the CMAXQUSB inter-
face board. Pin J1-7 connects to the MAX6946 clock pin
(SCL) and pin J1-3 connects to the data pin (SDA) for
I2C-compatibale communications. Slide both SW1 dip
switches on the CMAXQUSB interface board to the ON
position to connect pullup resistors to the SCL and SDA
signal lines for proper I2C communication.
The clock and data input pins can also be accessed at
the SCL and SDA EV kit PCB pads, respectively. An
external I2C-compatible controller can be connected to
the SCL, SDA, and GND PCB pads to communicate
with the MAX6946 IC. If the external device does not
have pullup resistors on the clock and data lines, 2.4kΩ
(typ) pullup surface-mount resistors (0603 size) must
be installed on R12 and R13 PCB pads for proper I2C
communication. The GND PCB pad must also be con-
nected to the external I2C controller.
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
_______________________________________________________________________________________ 3
Table 1. Voltage Source Selection
(Jumper JU1)
SHUNT
POSITION EV KIT FUNCTION
Installed*
Power supplied from the CMAXQUSB.
Note: Verify that the CMAXQUSB JU1 voltage
is configured to 3.3V.
Not installed User-supplied power source required at the
EV kit VDD and GND pads.
*
Default configuration.
Evaluate: MAX6946/MAX6947
Evaluating the MAX6947
The MAX6946 EV kit PCB can also be used to evaluate
the MAX6947 10-port expander. Remove the MAX6946
IC (U1) and replace it with the MAX6947 IC. The
MAX6947 is pin and function compatible with the
MAX6946, with the exception of pin 12. When evaluat-
ing the MAX6947, the OSC PC pad on the EV kit can be
used to access the AD0 pin. Refer to the
MAX6946/MAX6947 IC data sheet for a complete
description of part-to-part differences. Install a 3-pin
0.1in header at JU2 on the EV kit board and use a
shunt to configure the MAX6947 address. See Table 2
for jumper JU2 configuration.
Detailed Description of
Software
Note: Words in boldface are user-selectable features in
the software.
Graphical User Interface
The user interface (shown in Figure 1) is simple to oper-
ate. Use the computer mouse buttons or press the Tab
key to navigate through the GUI controls. The correct
I2C write operation is generated to update the internal
registers of the MAX6946 when any of these controls
are used.
The software divides EV kit functions into group boxes.
The Interface group box indicates the Device
Address,I2C Bus Speed, EV kit Status, and the last
operation Command Sent and Data Sent indicators.
This data is used to confirm proper device operation.
The Global Settings box allows the user to program
the configuration register, configure the global settings
for the 10 ports, and read the ports. The tabs on the
GUI are used to configure individual or groups of ports.
The MAX6946 EV kit software features additional func-
tions to simplify operation. Automatic Diagnostics
continually probe the interface board and the MAX6946
EV kit to make sure that all communications are main-
tained and that all devices are working. These functions
will create some activity on the I2C bus. The Silence
I2C Activity checkbox reduces I2C bus activity so trig-
gering of an oscilloscope while communicating to the
MAX6946 EV kit is made easy. The Factory Reset but-
ton programs the EV kit to the MAX6946 initial power-
up conditions.
MAX6946 Evaluation Kit/Evaluation System
4 _______________________________________________________________________________________
Table 2. MAX6947 Slave Address
Selection (Jumper JU2)
SHUNT
POSITION AD0 PIN MAX6947 SLAVE
ADDRESS
1-2 Connected to VDD 0x40
2-3 Connected to GND 0x48
Software Connection to CMAXQUSB
The MAX6946 EV kit software automatically searches
for the CMAXQUSB interface board and MAX6946 EV
kit during startup. The Status indicator shows if the
interface board and the MAX6946 EV kit are opera-
tional. If the interface board is not found, verify that the
command module and the USB cable are connected
properly, power is applied to the EV kit, and select the
YES button on the retry-connection message box.
The nonfunctional GUI can be viewed by selecting the
NO button on the retry-connection message box when
attempting to start the software without the CMAXQUSB
interface board being connected. Restart the software
with the interface board and EV kit properly connected
for normal operation.
Interface
The MAX6946 EV kit software automatically searches
for the MAX6946 during startup. If the software finds
the MAX6946, the Status indicator shows that the
MAX6946 is operational. If the MAX6946 is not found,
the Status indicator shows that the MAX6946 was not
found and the Device Address is set to “??”. Select the
Auto Detect option from the Device Address combo
box to search for the device address.
Use the I2C Bus Speed combo box to set the serial
bus speed to 400kHz or 100kHz.
Global Settings
The Global Settings group box includes controls to
configure the Global Current Sink from 2.5mA to
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
_______________________________________________________________________________________ 5
Figure 1. MAX6946 EV Kit Software Graphical User Interface (GUI)
Evaluate: MAX6946/MAX6947
20mA and the Hold-Off Delay, Ramp-Down Time, and
Ramp-Up Time from 0 to 4s. The other configuration
register bits can be programmed by configuring the
OSC/AD0, RSTPOR, PWM Staggered, Reset Run,
and Run Enable GUI controls. The Read P7-P0 and
Read P9-P8 buttons can be used to read the logical
state of the MAX6946 P7–P0 and P9 to P8 pins, repec-
tively. Refer to the MAX6946/MAX6947 IC data sheet
for a detailed description of each of these functions.
Note: During Read P7-P0 and Read P9-P8 operations,
the software automatically changes the r/w bit in the
address from 0 to 1 for proper I2C read operation.
Configuring the I/O Ports
The GUI tabs allow the user to configure the 10 I/O
ports individually or in groups. Once a port(s) tab has
been selected, the P_ Configuration group box allows
the user to configure the port as a Low-Logic Output,
High-Logic Output/ Logic Input, Static Constant-
Current Sink, constant-current PWM output (PWM
Duty Cycle slide bar), or disable the LED(s) (LED Off).
Individual port Sink Current can be configured to half
or full of the global current setting (Global Current
Sink). Configuring the I/O ports to Low-Logic Output
turns on the LEDs without regulating the LED current at
the respective port. Use the mouse or keyboard
left/right arrows to move the PWM Duty Cycle slide bar
from left to right to dim or brighten the LED(s). Refer to
the MAX6946/MAX6947 IC data sheet for a detailed
description of each of these registers. For true logic
input or output configuration of each port, remove the
shunts on header J2, install pullup resistors on PC pads
R2–R11, and use the software to configure the ports for
logic outputs or inputs. Refer to the
I/O Ports
section in
the MAX6946/MAX6947 IC data sheet for further
details.
Simple I2C Commands
There are two methods for communicating with the
MAX6946; through the normal user-interface panel
(Figure 1) or by using low-level I2C commands avail-
able through the 2-wire interface diagnostics (Figure
2) item from the main program’s Options menu. A win-
dow is displayed that allows I2C operations, such as
read byte and write byte. To stop normal user-interface
execution so that it does not override the manually set
values, turn off the update timer by unchecking the
Automatic Diagnostics checkbox in the MAX6946
main program.
The I2C dialog boxes accept numeric data in binary,
decimal, or hexadecimal. Hexadecimal numbers must
be prefixed by $ or 0x. Binary numbers must be exactly
eight digits of 0s and 1s. See Figure 2 for an example
using the 2-wire interface diagnostics tool.
Note: When using low-level I2C commands, the GUI
interface is no longer synchronized and will not reflect
the IC register settings.
General Troubleshooting
Problem: software reports it cannot find the board.
• Is the CMAXQUSB interface board power LED
(LED1) lit?
• Is the USB communications cable connected?
• Has windows plug-and-play detected the board?
Bring up Control Panel|System|Device Manager,
and look at what device nodes are indicated for
USB. If there is an “unknown device” node attached
to the USB, delete it—this forces plug-and-play to try
again.
Problem: Unable to find DUT (device-under-test).
• Is power connected to the MAX6946 EV kit?
• Are the SCL and SDA signals pulled up to VDD
through appropriate resistors (2.4kΩtyp)? The
CMAXQUSB interface board dip-switch SW1
enables the on-board resistors. There must be
pullup resistors somewhere on the I2C bus.
• If using jumper wires to connect to the I2C bus,
could the SCL and SDA signals be swapped? Could
the GND ground return be missing?
MAX6946 Evaluation Kit/Evaluation System
6 _______________________________________________________________________________________
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
_______________________________________________________________________________________ 7
Figure 2. 2-Wire Interface Utility. The above example shows a simple SMBusWriteByte operation using the included 2-wire interface
diagnostics tool. In this example, the software is writing 0x02 data to register address 0x0A (write to ports P0–P9) of the device with
a device address of 0x40. The above data sequence sets the MAX6946 10 ports to constant-current static sink output.
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
8 _______________________________________________________________________________________
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
SCL
SDA
VBUS
J1
J1-1
J1-3
J1-5
J1-7
J1-9
J1-11
J1-13
J1-15
J1-17
J1-19
J1-2
J1-4
J1-6
J1-8
J1-10
J1-12
J1-14
J1-16
J1-18
J1-20
N.C.
VDD
JU2
OPEN
1
2
3
OSC
GND
VLED
R11
OPEN
VLED
R10
OPEN
VLED
R9
OPEN
VLED
R8
OPEN
VLED
R7
OPEN
VLED
R6
OPEN
VLED
R4
OPEN
VLED
R5
OPEN
C4
OPEN
C3
10μF
VLED
VLED
GND
2
3
B
D1 GR
41
2
3
B
D2 GR
41
2
3
B
D3 GR
41
D4
J2
J2-20
J2-18
J2-16
J2-14
J2-12
J2-10
J2-8
J2-6
J2-4
J2-2 J2-1
J2-7
J2-3
J2-5
J2-13
J2-9
J2-11
J2-19
J2-15
J2-17
8
7
6
5
9
10
11
12
13
14
15
16
1234
VLEDVLED
R3
OPEN
R2
OPEN
C2
OPEN
JU1
VBUS
VDD
VDD
GND
VBUS
R13
OPEN
SDA
SDA
GND
SCL
VBUS
R12
OPEN
SCL
C1
0.1μF
VDD
SW1
R1
4.7kΩ
VDD
P6
P5
GND
P4
P3P2P1P0
SDA
SCL
VDD
RST
OSC P9 P8 P7
MAX6946
U1
Figure3. MAX6946 EV Kit Schematic
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
_______________________________________________________________________________________ 9
Figure 4. MAX6946 EV Kit Component Placement Guide—
Component Side
Figure 5. MAX6946 EV Kit PCB Layout—Component Side
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.
10
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Evaluate: MAX6946/MAX6947
MAX6946 Evaluation Kit/Evaluation System
Boblet
Figure 6. MAX6946 EV Kit PCB Layout—Solder Side Figure 7. MAX6946 EV Kit Component Placement Guide—
Solder Side
