MAX6951EVKIT MAXIM [Maxim Integrated Products], MAX6951EVKIT Datasheet - Page 5

• Manufacturer Part Number: MAX6951EVKIT
• Description: MAX6951 Evaluation Kit
• Manufacturer: MAXIM [Maxim Integrated Products]

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.
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
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
_______________________________________________________________________________________
Detailed Description
CC
input. The LDO linear regu-
of Hardware
MAX6951 Evaluation Kit
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
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.
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.
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
Figure 3. MAX6951 EV Kit Level-Translation Functional
Diagram
MAX6951
EV KIT
* +3.3V OR USER-SETTABLE VOLTAGE
POWER SUPPLY
+4V TO +6.5V
MAX604
LDO
EIGHT 7-SEGMENT DIGITS
OPTIONAL USER EXTERNAL
MAX6951
( * )
+3.3V SIDE
(+2.7V TO +5.5V)
REGULATED PS
MAX6951 EV Kit’s Power Source
3.3V
Stand-Alone Configuration
MAX1841
Jumper Selection
5V
+5V SIDE
5V
PC PARALLEL
PORT CABLE
5V PC
SIGNALS
5