Datasheet

MAX11120–MAX11128
1Msps, Low-Power, Serial 12-/10-/8-Bit,
4-/8-/16-Channel ADCs
24Maxim Integrated
Averaging Mode
In averaging mode, the device performs the specified
number of conversions and returns the average for each
requested result in the FIFO. The averaging mode works
with internal clock only.
Scan Modes and Unipolar/Bipolar Setting
When the Unipolar or Bipolar registers are configured
as pseudo-differential or fully differential, the analog
input pairs are repeated in this automated mode. For
example, if N is set to 15 to scan all 16 channels and
all analog input pairs are configured for fully-differential
conversion, the ADC converts the channels twice. In this
case, the user may avoid dual conversions on input pairs
by implementing Manual mode or using Custom_Int or
Custom_Ext scan modes.
Register Descriptions
The MAX11120–MAX11128 communicate between the
internal registers and the external circuitry through the
SPI-/QSPI-compatible serial interface. Table 1 details the
register access and control. Table 2 through Table 14
detail the various functions and configurations.
For ADC mode control, set bit 15 of the register code
identification to zero. The ADC Mode Control register
determines when and under what scan condition the
ADC operates.
To set the ADC data configuration, set the bit 15 of the
register code identification to one.
Table 1. Register Access and Control
Table 2. ADC Mode Control Register
REGISTER NAME
REGISTER IDENTIFICATION CODE DIN ≡ DATA INPUTS
BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT [10:0]
ADC Mode Control 0 DIN DIN DIN DIN DIN
ADC Configuration 1 0 0 0 0 DIN
Unipolar 1 0 0 0 1 DIN
Bipolar 1 0 0 1 0 DIN
RANGE 1 0 0 1 1 DIN
Custom Scan0 1 0 1 0 0 DIN
Custom Scan1 1 0 1 0 1 DIN
SampleSet 1 0 1 1 0 DIN
Reserved. Do not use. 1 1 1 1 1 DIN
BIT NAME BIT
DEFAULT
STATE
FUNCTION
REG_CNTL 15 0 Set to 0 to select the ADC Mode Control register
SCAN[3:0] 14:11 0001 ADC Scan Control register (Table 3)
CHSEL[3:0] 10:7 0000
Analog Input Channel Select register (Table 4).
See Table 3 to determine which modes use CHSEL[3:0] for the channel scan
instruction.
RESET[1:0] 6:5 00
RESET1 RESET0 FUNCTION
0 0 No reset
0 1 Reset the FIFO only (resets to zero)
1 0 Reset all registers to default settings (includes FIFO)
1 1 Unused