Rainbow Electronics MAX1499 - Manual (Page 23)

MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
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Default values: 0000h
In addition to automatic offset calibration, the
MAX1497/MAX1499 offer a user-defined custom offset
16-bit read/write register. The final result of the ADC
conversion is the input after autocalibration minus the value in the custom offset. The custom offset value
is stored in this register. D15 is the MSB. The data is
represented in two’s complement format.
ADC Custom Offset-Calibration Register (Read/Write)
MSB LSB
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
ADC Result Register 1 (Read Only)
MSB
LSB
(MAX1497)
LSB
(MAX1499)
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Default values: 0000h
ADC result register 1 is a 16-bit read-only register. This
register stores the 16 MSBs of the ADC result. The data
is represented in two’s complement format. For the MAX1499, the data is 16-bit and D15 is the
MSB. For the MAX1497, the data is 12-bit, D15 is the
MSB, and D4 is the LSB.
Default values: 0000h
The LED data register is a 16-bit read/write register.
This register updates from ADC result register 1 or from
the serial interface by selecting the SPI/ADC bit in the
control register. The data is represented in two’s com-
plement format. For the MAX1499, the data is 16-bit and D15 is the
MSB. For the MAX1497, the data is 12-bit, D15 is the
MSB, and D4 is the LSB, followed by 4 trailing sub-bits.
LED Data Register (Read/Write)
MSB
LSB
(MAX1497)
LSB
(MAX1499)
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
ADC Result Register 2 (Read Only)
MSB LSB
D3 D2 D1 D0 0 0 0 0
Default values: 00h
ADC result register 2 is an 8-bit read-only register. This
register stores the 4 LSBs of the ADC result. Use this result with the result in ADC result-register 1 to
form a 20-bit two’s complement conversion result.