19-0843; Rev 0; 7/07
MAX5128 Evaluation Kit/Evaluation System
General Description
The MAX5128 evaluation kit (EV kit) is a fully assembled
and tested surface-mount printed-circuit board (PCB)
that evaluates the MAX5128 22kΩ, linear-taper digital
potentiometer. The EV kit provides both a mechanical
pushbutton-controlled interface and a microprocessor-
controlled interface.
The MAX5128 evaluation system (EV system) consists
of the MAX5128 EV kit and the Maxim CMAXQUSB+
command module. The EV kit includes Windows
®
98SE/2000/XP-compatible software that provides a pro-
fessional user interface for exercising the MAX5128’s
features. The program is menu driven and offers a
graphical user interface (GUI) complete with control
buttons and a track bar.
Order the complete EV system (MAX5128EVCMAXQU+)
for comprehensive evaluation of the MAX5128 using a
PC. Order just the EV kit (MAX5128EVKIT+) if the
CMAXQUSB+ module has already been purchased
with a previous Maxim EV system.
Features
♦
Powered and Controlled from Standard USB
Interface (MAX5128EVCMAXQU+)
♦
2.7V to 5.25V Single-Supply Operation
♦
Windows 98SE/2000/XP-Compatible Evaluation
Software
♦
Easy-to-Use Menu-Driven Software
♦
Supports Pushbutton Inputs or CPU-Generated
Inputs
♦
Fully Assembled and Tested
Evaluate: MAX5128
Ordering Information
PART
MAX5128EVKIT+
MAX5128EVCMAXQU+
TEMP RANGE
0°C to +70°C*
0°C to +70°C*
IC PACKAGE
8 µDFN (2mm x 2mm)
8 µDFN (2mm x 2mm)
COMMAND MODULE
Not included
CMAXQUSB+
+Denotes
a lead-free and RoHS-compliant EV kit/EV system.
*This
limited temperature range applies to the EV kit PCB only. The MAX5128 IC temperature range is -40°C to +85°C.
Note:
The Maxim CMAXQUSB+ command module is required when using the MAX5128 EV kit software.
Component List
DESIGNATION
QTY
DESCRIPTION
0.1µF ±20%, 16V X7R ceramic
capacitor (0603)
Taiyo Yuden EMK107BJ104MA
Murata GRM188R71C104K
Not installed, capacitors (0603)
Dual-row, 2 x 10 right-angle
receptacle
2-pin header
3-pin headers
100k
Ω
±5% resistors (0603)
4.7k
Ω
±5% resistor (0603)
—
—
4
1
U3
1
DESIGNATION
SW1, SW2
U1
QTY
2
1
DESCRIPTION
Momentary pushbutton switches
MAX5128ELA+
(8-pin µDFN, 2mm x 2mm)
Dual CMOS switch debouncer
MAX6817EUT+T
(6-pin SOT23, 3mm x 3mm)
Dual CMOS inverter
Fairchild NC7WZ04P6X (6-pin SC70,
2mm x 2mm) (Top Mark: Z)
Shunts
PCB: MAX5128 Evaluation Kit+
C1
1
C2, C3
J1
JU1
JU2, JU3, JU4
R1, R2
R3
0
1
1
3
2
1
U2
1
Windows is a registered trademark of Microsoft Corp.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX5128 Evaluation Kit/Evaluation System
Evaluate: MAX5128
Component Suppliers
SUPPLIER
Murata Mfg. Co., Ltd.
Taiyo Yuden
PHONE
770-436-1300
800-348-2496
WEBSITE
www.murata.com
www.t-yuden.com
3) Ensure that jumper JU1 (VDD select) of the
CMAXQUSB+ is set for 5V operation.
4) For PC control, verify that shunts are installed in the
following positions:
JU1
JU2
JU3
Installed
Installed across pins 1-2
Installed across pins 1-2
Note:
Indicate that you are using the MAX5128 when contact-
ing these component suppliers.
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
•
MAX5128 EV system:
MAX5128 EV kit
CMAXQUSB+ command module (USB cable
included)
•
User-supplied Windows 98SE/2000/XP-compatible
PC with a spare USB port
•
DC power supply, 5V at 100mA (optional)
•
Digital multimeter (DMM)
Note:
In the following sections, software-related items
are identified by bolding. Text in
bold
refers to items
directly from the EV kit software. Text in
bold and
underlined
refers to items from the Windows
98SE/2000/XP operating system.
JU4
Installed across pins 2-3
5) Connect the ohmmeter across the H and W pads.
6) Carefully connect the boards by aligning the 20-pin
connector (J1) of the MAX5128 EV kit with the 20-
pin header (P3) on the CMAXQUSB+ command
module. Gently press them together.
7) Connect the USB cable from the PC to the EV kit
board. A
Building Driver Database
window pops
up in addition to a
New Hardware Found
message
when installing the USB driver for the first time. If
you do not see a window that is similar to the one
described above after 30s, remove the USB cable
from the board and reconnect it. Administrator privi-
leges are required to install the USB device driver
on Windows 98SE, 2000, and XP. Refer to the
TROUBLESHOOTING_USB.PDF document includ-
ed with the software if you have any problems dur-
ing this step.
8) 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\MAX5128
(default installation
directory) using the
Browse
button.
9) Start the EV kit software by opening its icon in the
Start | Programs
menu. The EV kit software main
window appears, as shown in Figure 1.
10) Wait until the program automatically detects the
MAX5128.
11) The MAX5128 EV kit is ready for evaluation.
Procedure
The MAX5128 EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on the power supply until all
connections are completed.
1) Visit the Maxim website (www.maxim-ic.com/evkit-
software) to download the latest version of the EV kit
software, 5128Rxx.ZIP. Save the EV kit software to a
temporary folder and uncompress the ZIP file.
2) Install the EV kit software on your computer by run-
ning the INSTALL.EXE program inside the temporary
folder. The program files are copied and icons are
created in the Windows
Start | Programs
menu.
2
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MAX5128 Evaluation Kit/Evaluation System
Detailed Description of Software
Each button of the GUI (Figure 1) corresponds to a
command used to set the wiper position or to program
the device.
Warning:
Do not remove the shunts of JU2 or JU3 from
their default positions while running the software (see
Table 1).
The software calculates the difference between the new
number entered and the old value and generates the
necessary up/down pulses to position the wiper to the
desired value.
Evaluate: MAX5128
Nonvolatile Programming
To program the nonvolatile memory, write the desired
value utilizing the GUI’s
Wiper Control
and press the
Write NV Register
button. This action will write the cur-
rent wiper position to the nonvolatile register of the
device. The 7-bit nonvolatile memory will retain the
value written to it even after power-down.
Resetting the MAX5128
The
Factory Reset
button programs the volatile and
nonvolatile memory to the midscale factory setting.
The software forces the wiper to the extreme of the
resistor string and generates 64 up/down pulses to
position the wiper to midscale.
Detailed Description of Hardware
The MAX5128 EV kit supports both mechanical push-
buttons and digital inputs to control the potentiometer’s
wiper position and is configured by setting jumpers
JU2 and JU3. By default, the MAX5128 IC’s logic inputs
(UP and DN) are controlled through the provided soft-
ware. Install shunts across pins 2-3 for both JU2 and
JU3 to control the device’s logic inputs through the
pushbutton switches (SW1 and SW2). See Table 1 for
the EV kit’s various jumper settings.
Table 1. Jumper Settings
JUMPER
SHUNT
POSITION
Installed*
Not installed
1-2*
JU2, JU3
2-3
1-2
JU4
2-3*
EV kit uses the CMAXQUSB+
command module's power source
DESCRIPTION
Low terminal L shunts to ground
Low terminal L floating
Wiper position software controlled
Wiper position pushbutton
controlled (SW1, SW2)
EV kit requires external power
supply across VCC pad
Figure 1. MAX5128 EV Kit Software Main Window
JU1
Wiper Control
The
track bar
in the
Wiper Control
group box allows
the user to change the wiper position between the high-
terminal (H) and low-terminal (L) end points. Use the
computer mouse, arrow keys, or page-up/page-down
keys to move the
track bar
between the 128 position
points. The wiper position can also be changed by
entering a numerical position (0 to 127) in the
Volatile
edit fields. The top
Volatile
field shows the wiper posi-
tion with respect to the
H
end point, while the bottom
Volatile
field shows the wiper position with respect to
the
L
end point.
*Default
position.
_______________________________________________________________________________________
3
MAX5128 Evaluation Kit/Evaluation System
Evaluate: MAX5128
Power Input
The MAX5128 EV kit requires a 2.7V to 5.25V power sup-
ply across the VCC and GND pads for normal operation.
The EV kit can either be powered through the CMAX-
QUSB+ command module’s power source or by an
external power supply. The EV kit’s default setting has
JU4 installed across pins 2-3 to utilize the CMAXQUSB+
command module’s power source (USB powered).
Configure the command module’s VDD select voltage to
3.3V or 5V (jumper JU1) when using the CMAXQUSB+
to power the MAX5128 EV kit. Install the EV kit’s JU4
jumper across pins 1-2 to use an external power supply.
2-3. The debouncer (U2) is provided to eliminate the
“contact bounce” that SW1 and SW2 may exhibit.
Toggle the SW1 pushbutton to increment the wiper
position. Toggle the SW2 pushbutton to decrement the
wiper position. Use the following procedure to program
the nonvolatile memory:
1) Force UP high (hold SW1).
2) Force DN high (hold SW2).
3) Transition input UP from high to low (release SW1)
and then release SW2.
Refer to the
Digital Interface
section of the MAX5128 IC
data sheet for a more detailed description.
Jumper JU1 can also be used to connect the MAX5128
L pin to the circuit ground, providing a ground refer-
ence during evaluation.
Digital Interface
Wiper positioning can be controlled through the
momentary pushbutton switches (SW1 and SW2) by
installing the jumpers of both JU2 and JU3 across pins
VCC
SW1
1
4
1
IN1
5
VCC
OUT1
VCC
5
VCC
A1
Y1
1
2
3
JU2
R1
100kΩ
VCC
UP
7
C2
OPEN
UP
V
CC
1
C1
0.1μF
6
1
6
U1
U2
MAX6817
SW2
1
4
3
IN2
GND
2
OUT2
4
3
A2
U3
NC7WZ04P6X
1
2
3
JU3
R2
100kΩ
MAX5128
DN
6
C3
OPEN
DN
N.C.
8
GND
5
H
W
L
2
3
4
JU1
H
W
L
Y2
GND
2
4
VCC
J1
J1-2
J1-4
J1-6
J1-8
J1-10
J1-12
J1-14
J1-16
J1-18
J1-20
J1-1
J1-3
J1-5
J1-7
J1-9
J1-11
J1-13
J1-15
J1-17
J1-19
UP
DN
R3
4.7kΩ
VCC
32
JU4
1
VCC
GND
Figure 2. MAX5128 EV Kit Schematic
4
_______________________________________________________________________________________
MAX5128 Evaluation Kit/Evaluation System
Evaluate: MAX5128
Figure 3. MAX5128 EV Kit Component Placement Guide—
Component Side
Figure 4. MAX5128 EV Kit PCB Layout—Component Side
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