19-2180; Rev 0; 11/01
MAX6951 Evaluation Kit
General Description
The MAX6951 evaluation kit (EV kit) is an assembled and
tested PC board that demonstrates the MAX6951 serially
interfaced eight-digit LED display driver IC. The EV kit is
powered by a user-supplied +4VDC to +6.5VDC power
supply. A configurable +3.3V or user-configurable low-
dropout (LDO) linear regulated power supply provides
power for the entire EV kit. An SPI™-compatible serial
interface is connected to an IBM PC-compatible com-
puter’s parallel port for easy evaluation. The EV kit can
easily be reconfigured for interfacing with a user-sup-
plied microcontroller (standalone operation).
Windows
®
95/98-compatible software provides a user-
friendly interface to demonstrate the various features of
the MAX6951 IC. The program is menu driven and
offers a graphic interface with control buttons. Windows
NT/2000 support is available; contact the factory for
details.
Features
o
Eight-Digit 7-Segment + dp Common-Cathode
Display
o
SPI-Compatible Serial Interface
o
Configurable Built-In LDO Linear Regulated Power
Supply Demonstrates +3.3V or Other Voltages
o
Reconfigurable for Stand-Alone Operation
(with an External Microcontroller)
o
Easy-to-Use Menu-Driven Software
o
Includes Windows 95/98-Compatible Software
o
Assembled and Tested
Evaluates: MAX6951
Ordering Information
PART
MAX6951EVKIT
TEMP. RANGE
0°C to +70°C
IC PACKAGE
16 QSOP
Component List
DESIGNATION
C1
QTY
1
DESCRIPTION
10µF
±20%,
16V X7R ceramic
capacitor (1812)
TDK C4532X7R1C106M
10µF
±10%,
10V tantalum
capacitor (A)
Kemet T494A106K010AS
0.1µF
±10%,
16V X7R ceramic
capacitors (0603)
Murata GRM39X7R104K016AD
47µF, 6.3V low-ESR POSCAP (C)
capacitor
Sanyo 6TPA47M
18pF
±5%,
50V COG ceramic
capacitor (0603)
Murata GRM39COG180J050AD
1µF, 16V X7R ceramic capacitor
(1206)
Murata GRM42-6X7R105K016
Red two-digit 7-segment
common-cathode LED displays
(0.560in)
Fairchild MAN6940
DESIGNATION
D5, D6
J1
J2
R1, R2, R3
R4
R5, R6
U1
U2
U3
None
None
None
None
C7
1
QTY
2
1
1
3
1
2
1
1
1
1
1
1
1
DESCRIPTION
200mA, 25V Schottky diodes
(SOT23)
Fairchild BAT54C
DB25 male right-angle connector
5-pin header
10kΩ
±5%
resistors (0805)
93.1kΩ
±1%
resistor (0805)
Not installed (0805)
MAX6951EEE (16-pin QSOP)
MAX604ESA (8-pin SO)
MAX1841EUB (10-pin µMAX)
MAX6951 PC board
MAX6951 data sheet
MAX6951 EV kit data sheet
3 1/2in software diskette,
MAX6951 EV kit
C2
1
C3, C4
2
C5
1
C6
1
D1–D4
4
Windows is a registered trademark of Microsoft Corp.
SPI is a trademark of Motorola, Inc.
1
________________________________________________________________
Maxim Integrated Products
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.
MAX6951 Evaluation Kit
Evaluates: MAX6951
Component Suppliers
SUPPLIER
Fairchild
Kemet
Murata
Sanyo
TDK
PHONE
888-522-5372
864-963-6300
770-436-1300
619-661-6835
847-803-6100
FAX
972-910-8036
864-963-6322
770-436-3030
619-661-1055
847-390-4405
6) Observe as the program automatically detects the
parallel port address of the MAX6951 EV kit and starts
the main program.
7) Header J2 is provided to monitor the parallel port pins
supplying the CLK_P,
CS_P,
DIN_P (+5V signals),
and loopback signals. The CLK,
CS,
and DIN pads
on the EV kit’s left side are +3.3V level-shifted signals
from the MAX1841 level translator. Both signal loca-
tions can be used for monitoring.
Note:
When contacting suppliers, please indicate that you are
using the MAX6951.
Quick Start
Required Equipment
Before you begin, the following equipment is needed:
• IBM PC-compatible computer running Windows 95/98
•
•
•
Computer monitor with 800 x 600 minimum screen
resolution
Parallel printer port (25-pin female socket on the
back of the computer)
Standard 25-pin, straight-through, male-to-female
cable (printer extension cable) to connect the com-
puter’s parallel port to the MAX6951 EV kit
DC power supply capable of supplying between
+4V to +6.5V and at least 500mA current
Detailed Description
of Software
Note:
Words in
boldface
are user-selectable features in
the software.
User Interface
The user interface is easy to operate. A mouse or the
Tab key can be used to navigate among various items of
the main display panel. Upon starting the program, the
MAX6951 EV kit display is programmed to initialize in
Normal mode,
display
8-digits
in
No-decode mode,
blinking at a
Slow Rate
with an
8/16
(50% duty cycle)
display intensity, and display the contents of the initial-
ized MAX6951
SRAM Plane P0 and P1
contents. The
MAX6951 EV kit 8-digit LED display should alternate
between HELLO--¯-- and --¯--6951. Figure 1 is the main
panel for the MAX6951 EV kit.
•
Procedure
Do not turn on the power until all connections are
made.
1) Connect a cable from the computer’s parallel port to
the MAX6951 EV kit. Use a straight-through, 25-pin,
female-to-male cable. The EV kit software uses a
loopback connection to confirm that the correct port
has been selected.
2) The MAX6951.EXE software program can be run
from the floppy or hard drive. Use the Windows pro-
gram manager to run the program. If desired, you
may use the INSTALL.EXE program to copy the files
and create icons for them in the Windows 95/98 Start
menu. An uninstall program is included with the soft-
ware. Click on the UNINSTALL icon to remove the EV
kit software from the hard drive.
3) Connect the power-supply positive terminal to the
VIN pad and negative terminal to the GND pad.
4) Turn on the power supply and set it to +4V.
5) Start the MAX6951 program by opening its icon in
the Start menu.
Main Panel Display Controls
The
Display mode
group of radio buttons determines the
mode of operation of the MAX6951 EV kit. Clicking on the
Shutdown
radio button puts the MAX6951 EV kit in shut-
down mode. The display is blank and the EV kit draws the
least amount of current in this mode. Selecting the
Normal
radio button places the MAX6951 EV kit in the
normal mode of operation. Clicking on the
Test
radio but-
ton puts the MAX6951 EV kit in test mode. All eight digits
and all segment LEDs on the MAX6951 EV kit are illumi-
nated with a 50% duty cycle (8/16). To change the blink
rate, click on one of the
Blink Rate
radio buttons. Once
selected, the
Blink Rate
can be adjusted by using the
Up-Down Arrows
on the keyboard. The 7-segment
digits on the computer monitor do not blink. Intensity of
the MAX6951 EV kit LEDs can be adjusted by using the
mouse to move the
Intensity Control
track bar. Once
selected, the
Intensity Control
can be adjusted with
the left-right arrows on the keyboard. The number of
digits displayed is adjusted with the
Digit Scan Limit
button or list box. To set the scan limit to eight digits,
click on the
Eight Digits
button or use the mouse to
scroll the list box to the desired number of digits. Once
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_______________________________________________________________________________________
MAX6951 Evaluation Kit
Evaluates: MAX6951
Figure 1. Main Panel for MAX6951 EV Kit
the
Digit Scan Limit
list box is selected, the number
keys can be used to change values. If one digit is
desired, click on the
One Digit
button.
The
SRAM Data Planes
group of radio buttons select
which data plane is displayed on the computer monitor
7-segment digits and is updated when a digit value is
changed. Selecting the
Plane P0
radio button displays
the contents of Plane P0 in the MAX6951. The program
keeps track of data written to all registers in the
MAX6951 hardware. Clicking on
Plane P1
displays the
contents of Plane P1 written to hardware. Selecting
Plane P0 and P1
displays the contents of Plane P0 by
default. To clear the MAX6951 SRAM Plane registers
P0 and P1, click on the
Clear Planes
button.
Hexadecimal Decode Mode
The
Digit Hexadecimal Decode
checkboxes and but-
tons select which digits are represented in hexadecimal
decode mode. A
✔
in a
Digit
checkbox indicates that the
digit is in hexadecimal decode mode. A blank Digit
checkbox indicates the digit is in
No-decode mode.
Clicking on the
All Digits
button places all eight digits in
hexadecimal decode mode or clicking on
None
places
all digits in no-decode mode.
When a digit is in
Hexadecimal Decode mode,
the digit’s
list box
up-down arrows
are used to select a value on
the numbered keypad once the digit’s list box has been
selected. To activate a digit’s
decimal point,
click on the
digit’s decimal point
with the mouse or click again to
deactivate the decimal point.
For digits in
no-decode mode,
use the mouse to click on
the desired segment of the digit’s 7-segment display.
Note that the digit’s list box
up-down arrows
are dis-
abled. To activate a
digit’s decimal point,
click on the
digit’s decimal point
with the mouse or click again to
deactivate the decimal point. The left-side list box of each
3
_______________________________________________________________________________________
MAX6951 Evaluation Kit
Evaluates: MAX6951
Figure 2. SPI Utility Showing the Settings to Communicate with the MAX6951 EV Kit
digit displays the no-decode hex value written to the
MAX6951 hardware.
Digit 0 (left side) through digit 7 (right side) display the
contents of the selected MAX6951 SRAM data plane,
P0 or P1.
updates the main panel. Pressing the
Clear Planes
button clears SRAM Planes P0 and P1.
General-Purpose SPI Utility
There are two methods for communicating with the
MAX6951 (Figure 2): through the Main Panel display or
through the general-purpose
SPI utility.
The utility config-
ures the SPI parameters such as clock polarity (CPOL),
clock phase (CPHA), and chip select (CS) polarity. The
fields where pin numbers are required apply to the pins
of the parallel port connector. When using the SPI utility,
the Main Panel display no longer keeps track of changes
sent to hardware. The SPI utility is preconfigured for the
proper setting of CPOL, CPHA, and CS.
The utility only handles the data in byte (8-bit) format.
Data that is longer than a byte must be handled as mul-
Pulldown Menus and Saving Data
All available functions except for changing a digit’s
value can be changed using the
pulldown menu.
Hot
keys (Alt
+ underlined letter)
provide an alternative to
using the mouse to configure the MAX6951 EV kit.
Pressing on the
Save Data
button saves all the current
registers and SRAM (P0 and P1) data to the program’s
directory. Pressing on the
Restore Data
button
retrieves the saved register and SRAM (P0 and P1)
data and sends it to the MAX6951 EV kit hardware and
4
_______________________________________________________________________________________
MAX6951 Evaluation Kit
tiple bytes. Thus, for the MAX6951 EV kit, 16-bit words
must be broken into two 8-bit bytes. Set the
bits
list box
to 16 so the clock sends 16 pulses on the CLK pin. The
command byte is entered first and then the data byte.
To write data to the MAX6951 EV kit hardware, enter
the data into the field: Data bytes to be written. The
data bytes must be hexadecimal and prefixed by 0x.
Separate each byte with a comma. Press the
Send
Now
button to write the data to the MAX6951 EV kit. For
example, to set the MAX6951 EV kit’s display intensity
to 2/16, enter the command word 0x02 and data word
0x01, as: 0x02,0x01 and click the
Send Now
button.
of the MAX6951 IC.
The MAX6951 IC is configured to oscillate nominally at
4MHz by external capacitor C6 and resistor R4. The EV
kit can be reconfigured for evaluating other frequencies
by applying an external TTL/CMOS-compatible clock to
the EXT_OSC pad and reconfiguring jumper JU7. The
MAX6951’s peak segment current is set to 20mA by
OPTIONAL USER EXTERNAL
REGULATED PS
+4V TO +6.5V
(+2.7V TO +5.5V)
POWER SUPPLY
Evaluates: MAX6951
Detailed Description
of Hardware
The MAX6951 EV kit demonstrates the MAX6951 8-digit
7-segment + dp common-cathode LED display driver
IC. The EV kit also features a MAX604 +3.3V LDO linear
regulator providing up to 500mA for the MAX6951 and
LEDs. The user can reconfigure JU6 to provide a volt-
age from +2.7V up to +5.5V to power the circuit. The
EV kit’s input requires a +4VDC to +6.5VDC power sup-
ply capable of supplying at least 500mA for a +3.3V
evaluation. The EV kit’s LDO linear regulator input volt-
age must be higher than the circuit voltage.
Additionally, an externally regulated +2.7V up to +5.5V
power supply can be used to power the EV kit,
EXT_VCC after reconfiguring jumper JU1.
The EV kit connects to an IBM-compatible PC computer
parallel port, which permits easy evaluation of the EV
kit. The EV kit’s SPI-compatible serial interface is con-
nected to a MAX1841 (U3) level translator. The transla-
tor level-shifts the computer’s parallel port logic +5V
signals to the EV kit’s logic +3.3V or circuit voltage level
chosen by the user. By reconfiguring the appropriate
jumper (JU1), the translator can function with voltages
down to +2.7V. The level translator’s parallel port side
is powered by parallel ports D5 to D7 data pins, diodes
D5/D6, and capacitor C7, which provide approximately
+5V to the translator DV
CC
input. The LDO linear regu-
lator supplies power to the translator’s output side. A
five-pin header (J2) is provided for monitoring the +5V
CLK_P,
CS_P,
DIN_P nonlevel-translated, and LOOP-
BACK signals coming from the parallel port cable.
The EV kit can be easily reconfigured for stand-alone
operation and can be connected to an external micro-
controller for evaluation. Pullup resistors R1, R2, and R3
are provided on the EV kit for the MAX6951’s CLK,
CS,
and DIN pins. PC board pads are provided for interfac-
ing or monitoring the CLK,
CS,
and DIN +3.3V or circuit
voltage level chosen by the user, level-translated pins
MAX604
LDO
MAX6951
EV KIT
(*)
5V
PC PARALLEL
PORT CABLE
5V PC
SIGNALS
5V
MAX6951
3.3V
MAX1841
EIGHT 7-SEGMENT DIGITS
+3.3V SIDE
* +3.3V OR USER-SETTABLE VOLTAGE
+5V SIDE
Figure 3. MAX6951 EV Kit Level-Translation Functional
Diagram
resistor R4.
The parallel port signals are level translated and
buffered from the EV kit by the MAX1841 level transla-
tor. However, the two sides are not galvanically isolat-
ed. Figure 3 shows the parallel port and level-transla-
tion interface for the MAX6951 EV kit.
Jumper Selection
MAX6951 EV Kit’s Power Source
The MAX6951 EV kit can be easily powered by a sepa-
rate externally regulated power supply. The 2-pin
jumper JU1 selects the power source for the EV kit cir-
cuit. The external power source must be in the +2.7V to
+5.5V range and must be capable of supplying at least
500mA current. The output of the EV kit’s built-in LDO
power regulator must be isolated from the external
power supply. Table 1 lists the jumper options.
Stand-Alone Configuration
The MAX6951 EV kit features several jumpers to recon-
figure the EV kit for stand-alone operation or PC/soft-
ware control. The 2-pin jumpers, JU2 to JU5, select the
evaluation mode for the EV kit. Table 2 lists the jumpers
to cut open or short for the desired evaluation mode.
Note:
All jumpers must be configured for only one
mode at a time and the proper voltage selected for
stand-alone mode.To select other output voltages
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