Rainbow Electronics MAX1495 - Manual (Page 7)

MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
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Pin Description
PIN
MAX1491
MAX1493
MAX1495
NAME FUNCTION
1 30 INTREF
Internal Reference Logic Input. Connect to GND to select external reference mode. Connect
to DV
DD
to select the internal reference mode.
2 31 DV DD
Digital Power Input. Connect DV DD to a 2.7V to 5.25V power supply. Bypass DV DD to GND
with a 0.1µF and a 4.7µF capacitor.
3 32 GND Ground
4 1 AV DD
Analog Power Input. Connect AV DD to a 2.7V to 5.25V power supply. Bypass AV DD to GND
with a 0.1µF and a 4.7µF capacitor.
5 2 AIN+
Positive Analog Input. Positive side of fully differential analog input. Bypass A IN+ to GND with
a 0.1µF or greater capacitor.
6 3 AIN-
Negative Analog Input. Negative side of fully differential analog input. Bypass A
IN-
to GND
with a 0.1µF or greater capacitor.
7 4 REF-
Negative Reference Input. For internal reference operation, connect REF- to GND. For
external reference operation, bypass REF- to GND with a 0.1µF capacitor and set V
REF- from
-2.2V to +2.2V, provided V REF+ > V REF- .
8 5 REF+
Positive Reference Input. For internal reference operation, connect a 4.7µF capacitor from
REF+ to GND. For external reference operation, bypass REF+ to GND with a 0.1µF capacitor
and set V
REF+ from -2.2V to +2.2V, provided V REF+ > V REF- .
9 6 LOWBATT Low Batter y Inp ut. W hen V LOWB ATT < 2.048V ( typ ) , the LO WBATT sym b ol on the LC D tur ns on.
10 7 RANGE
Range Logic Input. RANGE controls the fully differential analog input range. Connect to GND
for the ±2V input range. Connect to DV
DD for the ±200mV input range.
11 8 DPSET1
Decimal Point Logic Input 1. Controls the decimal point of the LCD. See the Decimal Point
Control section.
12 9 DPSET2
Decimal Point Logic Input 2. Controls the decimal point of the LCD. See the Decimal Point
Control section.
13 10 PEAK
Peak Logic Input. Connect to DV DD to display the highest ADC value on the LCD. Connect to
GND to disable the peak function.
14 11 HOLD
Hold Logic Input. Connect to DV DD to hold the current ADC value on the LCD. Connect to
GND to update the LCD at a rate of 2.5Hz and disable the hold function. For the MAX1495,
placing the device into hold mode initiates an enhanced offset calibration. Assert HOLD high
for a minimum of 2s to ensure the completion of enhanced offset calibration.
15 12 SEG1 LCD Segment 1 Driver
16 13 SEG2 LCD Segment 2 Driver
17 14 SEG3 LCD Segment 3 Driver
18 15 SEG4 LCD Segment 4 Driver
19 16 SEG5 LCD Segment 5 Driver
20 17 SEG6 LCD Segment 6 Driver