JAJSPF5 April 2024 ADS9813
ADVANCE INFORMATION
The ADS9813 features a common-mode (CM) rejection circuit at the analog inputs that supports CM voltages up to ±12V. The CM voltage for differential inputs is given by Equation 1. On power-up or after reset, the common-mode voltage range for the analog input channels is ±12V (WIDE_CM_EN1 = 0b). In all cases, make sure the voltage at the analog inputs is within the Absolute Maximum Ratings.
As described in Table 6-3, optimize the CM voltage rejection circuit for various CM voltages for differential inputs.
COMMON-MODE (CM) RANGE | CM_CTRL_EN | ANALOG INPUT CHANNELS 1–4 | ANALOG INPUT CHANNELS 5–8 | ||
---|---|---|---|---|---|
CM_EN_CH[4:1] | CM_RNG_CH[4:1] | CM_EN_CH[8:5] | CM_RNG_CH[8:5] | ||
CM ≤ ±1V | 1 | 0 | Don't care | 0 | Don't care |
CM ≤ ±RANGE / 2 | 1 | 0 | 1 | 0 | |
CM ≤ ±6V | 2 | 2 | |||
CM ≤ ±12V | 1 | 1 |
The CM voltage rejection circuit is configured depending on the analog input range of the PGA when using single-ended inputs. Table 6-4 lists the recommended configuration for single-ended inputs for various analog input voltage ranges.
PGA ANALOG INPUT RANGE | CM_CTRL_EN | ANALOG INPUT CHANNELS 1–4 | ANALOG INPUT CHANNELS 5–8 | ||
---|---|---|---|---|---|
CM_EN_CH[4:1] | CM_RNG_CH[4:1] | CM_EN_CH[8:5] | CM_RNG_CH[8:5] | ||
±2.5V, ±3.5V, and ±5V | 1 | 0 | Don't care | 0 | Don't care |
±7V, ±10V, and ±12V | 1 | 0 | 1 | 0 |