SBASAM0B March 2024 – November 2024 ADS127L18
PRODMIX
The ADC supports channel-to-channel averaging to create higher resolution data from the original channel data. Averaging occurs across channels in groups of two, four, or eight, as programmed by the AVG_MODE[1:0] bits of the GEN_CFG2 register. In typical use, the signal is applied in parallel to the channels to be averaged. When the noise between channels is uncorrelated, the dynamic range improvement in dB is 20 × log(√n), where n = number of channels averaged. Program the channels to the same data rate (OSR) in averaging mode.
Averaging is performed after the offset, gain, and output code clip operations. Therefore, averaging is based on the final output data from each channel. If clipped data occurs for a channel, the clipped data also reflects in the averaged result. The MOD_FLAG of the DP_STATUS header is an OR of the original channel MOD_FLAG status bits. Table 7-11 shows how the averaged data is assigned to the ADC channel number. The original channel data are not available. The averaged data is compatible in TDM and daisy-chain operation.
ASSIGNED CHANNEL | TWO-CHANNEL AVERAGING | FOUR-CHANNEL AVERAGING | EIGHT-CHANNEL AVERAGING |
---|---|---|---|
CH0 | Average of CH0, CH1 | Average of CH0−CH3 | Average of CH0−CH7 (ADS127L18) |
CH1 | Average of CH2, CH3 | Average of CH4−CH7 (ADS127L18) | — |
CH2 | Average of CH4, CH5 (ADS127L18) | — | — |
CH3 | Average of CH6, CH7 (ADS127L18) | — | — |