SBASAM0 March 2024 ADS127L18
ADVANCE INFORMATION
The ADC supports channel-to-channel averaging modes to create higher resolution data from the original channel data. Averaging across channels occurs in combinations 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 signal noise between channels is uncorrelated, the dynamic range improvement is (+dB) = 20 × log(√n), where n = number of channels averaged. In average mode, the data rate (OSR) between channels is the same.
Averaging is performed after the offset, gain, and output code clip operations for each channel. If the channel data are not calibrated by the user registers, the offset and gain errors also average. If clipped data occurs in 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 the data lanes (active DOUT pins) that provide averaged data. The original channel data are not available. TDM operation is also available when channel data are averaged.
DATA LANES | 2-CHANNEL AVERAGE MODE | 4-CHANNEL AVERAGE MODE | 8-CHANNEL AVERAGE MODE |
---|---|---|---|
DOUT0 | ADS127L14: Average of CH0, CH1 ADS127L18: Average of CH0, CH1 |
ADS127L14: Average of CH0−CH3 ADS127L18: Average of CH0−CH3 |
ADS127L14: N/A
ADS127L18: Average of CH0−CH7 |
DOUT1 | ADS127L14: Average of CH2, CH3 ADS127L18: Average of CH2, CH3 |
ADS127L14: 0 ADS127L18: Average of CH4−CH7 |
0 |
DOUT2 | ADS127L14: 0 ADS127L18: Average of CH4, CH5 |
0 | 0 |
DOUT3 | ADS127L14: 0 ADS127L18: Average of CH6, CH7 |
0 | 0 |
DOUT4−DOUT7 | 0 | 0 | 0 |