Datasheet

MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
8 _______________________________________________________________________________________
Pin Description (continued)
PIN
MAX1491
MAX1493
MAX1495
NAME FUNCTION
21 18 SEG7 LCD Segment 7 Driver
22 19 SEG8 LCD Segment 8 Driver
23 20 SEG9 LCD Segment 9 Driver
24 21 SEG10 LCD Segment 10 Driver
25 25 BP3 LCD Backplane 3 Driver
26 26 BP2 LCD Backplane 2 Driver
27 27 BP1 LCD Backplane 1 Driver
28 29 V
NEG
-2.5V Charge-Pump Voltage Output. Connect a 0.1µF capacitor from V
NEG
to GND.
— 22 SEG11 LCD Segment 11 Driver
— 23 SEG12 LCD Segment 12 Driver
— 24 SEG13 LCD Segment 13 Driver
— 28 DPON
Decimal Point Enable Input. Controls the decimal point of the LCD. See the Decimal Point
Control section. Connect to DV
DD
to enable the decimal point.
MAX1493
MAX1495
BINARY-TO-BCD
CONVERTERS
AND
LCD DRIVERS
ADC
INPUT
BUFFERS
-2.5V
AIN+
AIN-
REF+
REF-
+2.5V
AV
DD
DV
DD
2.048V
BANDGAP
REFERENCE
OSCILLATOR/
CLOCK
DPSET1 DPSET2
SEG1
SEG13
BP1
BP2
BP3
RANGE
CONTROL
+2.5V
GND
A = 1.22
TO
CONTROL
CHARGE
PUMP
-2.5V
LOWBATTV
NEG
INTREF
DPON HOLD
PEAK
Figure 1. MAX1493/MAX1495 Functional Diagram