Datasheet
ADS1118
www.ti.com
SBAS457D –OCTOBER 2010–REVISED OCTOBER 2013
REGISTERS
The ADS1118 has two registers that are accessible via the SPI port. The Conversion register contains the result
of the last conversion. The Config register allows the user to change the ADS1118 operating modes and query
the status of the devices.
Conversion Register
The 16-bit Conversion register contains the result of the last conversion in binary twos complement format.
Following power-up, the Conversion register is cleared to '0', and remains '0' until the first conversion is
completed. The register format is shown in Table 5.
Table 5. Conversion Register (Read-Only)
BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
NAME D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Config Register
The 16-bit Config register can be used to control the ADS1118 operating mode, input selection, data rate, PGA
settings, and temperature sensor mode. The register format is shown in Table 6.
Table 6. Config Register (Read/Write)
15 14 13 12 11 10 9 8
SS MUX2 MUX1 MUX0 PGA2 PGA1 PGA0 MODE
7 6 5 4 3 2 1 0
DR2 DR1 DR0 TS_MODE PULL_UP_EN NOP1 NOP0 NOT USED
Default = 058Bh.
Bit 15 SS: Single-shot conversion start
This bit is used to start a single conversion. SS can only be written when in power-down state and has no
effect when a conversion is ongoing.
When writing:
0 = No effect
1 = Start a single conversion (when in power-down state)
Always reads back as '0' (default).
Bits[14:12] MUX[2:0]: Input multiplexer configuration
These bits configure the input multiplexer.
000 = AIN
P
is AIN0 and AIN
N
is AIN1 (default) 100 = AIN
P
is AIN0 and AIN
N
is GND
001 = AIN
P
is AIN0 and AIN
N
is AIN3 101 = AIN
P
is AIN1 and AIN
N
is GND
010 = AIN
P
is AIN1 and AIN
N
is AIN3 110 = AIN
P
is AIN2 and AIN
N
is GND
011 = AIN
P
is AIN2 and AIN
N
is AIN3 111 = AIN
P
is AIN3 and AIN
N
is GND
Bits[11:9] PGA[2:0]: Programmable gain amplifier configuration
These bits configure the programmable gain amplifier.
000 = FS is ±6.144 V
(1)
100 = FS is ±0.512 V
001 = FS is ±4.096 V
(1)
101 = FS is ±0.256 V
010 = FS is ±2.048 V (default) 110 = FS is ±0.256 V
011 = FS is ±1.024 V 111 = FS is ±0.256 V
(1) This parameter expresses the full-scale range of the ADC scaling. In no event should more than VDD + 0.3 V be applied to this device.
Copyright © 2010–2013, Texas Instruments Incorporated Submit Documentation Feedback 21
Product Folder Links: ADS1118