ZHCSCA6B April 2014 – October 2020 ADS4245-EP
PRODUCTION DATA
The ADS4245 has an internal offset corretion algorithm that estimates and corrects dc offset up to ±10mV. The correction can be enabled using the ENABLE OFFSET CORR serial register bit. Once enabled, the algorithm estimates the channel offset and applies the correction every clock cycle. The time constant of the correction loop is a function of the sampling clock frequency. The time constant can be controlled using the OFFSET CORR TIME CONSTANT register bits, as described in Table 7-3.
After the offset is estimated, the correction can be frozen by setting FREEZE OFFSET CORR = 0. Once frozen, the last estimated value is used for the offset correction of every clock cycle. Note that offset correction is disabled by default after reset.
OFFSET CORR TIME CONSTANT | TIME CONSTANT, TCCLK (Number of Clock Cycles) | TIME CONSTANT, TCCLK × 1/fS (ms)(1) |
---|---|---|
0000 | 1M | 7 |
0001 | 2M | 13 |
0010 | 4M | 26 |
0011 | 8M | 52 |
0100 | 16M | 105 |
0101 | 32M | 210 |
0110 | 64M | 419 |
f0111 | 128M | 839 |
1000 | 256M | 1678 |
1001 | 512M | 3355 |
1010 | 1G | 6711 |
1011 | 2G | 13422 |
1100 | Reserved | — |
1101 | Reserved | — |
1110 | Reserved | — |
1111 | Reserved | — |