Manual
MAX1492/MAX1494
3.5- and 4.5-Digit, Single-Chip ADCs
with LCD Drivers
24 ______________________________________________________________________________________
Default values: 7CF0h (for MAX1492, +1999)
4E1Fh (for MAX1494, +19,999)
The overrange register is a 16-bit read/write register
(D15 is the MSB). When the conversion result exceeds
the value in the overrange register, the OVER bit in the
status register latches to 1. The LCD shows a 1 fol-
lowed by 4 dashes for the MAX1494 or a 1 followed by
3 dashes for the MAX1492 (see Table 4).
The data is represented in two’s complement format.
SEG_SEL SPI/ADC HOLD PEAK DISPLAYS VALUES FROM
1 X X X LCD Segment Registers
0 1 X X LCD Display Register (User Written)
0 0 1 X LCD Display Register
0 0 0 1 Peak Register
0 0 0 0 ADC Result Register
Table 6. LCD Priority Table
X = Don’t care.
Underrange Register (Read/Write):
Overrange Register (Read/Write):
MSB
LSB
D15
D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1
D0
Default values: 8300h (for MAX1492, -2000)
B1E0h (for MAX1494, -20,000)
The underrange data register is 16-bit read/write regis-
ter (D15 is the MSB). When the conversion result falls
below the value in the underrange register, the UNDR
bit in the status register sets to 1. The LCD shows a -1
followed by 4 dashes for the MAX1494 or a -1 followed
by 3 dashes for the MAX1492 (see Table 4).
The data is represented in two’s complement format.
MSB
LSB
D15
D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1
D0
Default values: 0000h
The LCD segment-display register 1 is a 16-bit
read/write register. When the SEG-SEL bit (in the con-
trol register) is set to 1, the MAX1492/MAX1494 provide
direct access to individual LCD segments. The bits in
the LCD segment-display register determine if a seg-
ment is on or off. Write a 0 to this register to turn on a
segment and a 1 to turn off a segment.
MSB
LSB
A2
G2 D2
F2 E2
DP2 ANN B1 C1 A1 G1 D1
F1 E1
DP1
0
LCD Segment-Display Register 1 (Read/Write):