58.8.4 AFE Transfer Function

The first operation of the AFE is a sampling function relative to V_DAC. V_DAC is generated by an internal DAC0 or DAC1. All operations after the Sample-and-Hold are differential relative to an internal common mode voltage V_CM = V_VREFP/2.

In Differential mode, the Sample-and-Hold common mode voltage is equal to V_DAC = V_VREFP/2 (set by software DAC0 and DAC1 to code 512).

In Single-ended mode, V_DAC is the common mode voltage. V_DAC is the output of DAC0 or DAC1 voltage. All operations after the Sample-and-Hold are differential, including those in Single-ended mode.

For the formula example, the internal DAC0 or DAC1 is set for the code 512.

The DATA code in AFEC_CDR is up to 16-bit positive integer or two’s complement (signed integer).

The code does not exceed 4095 when the field AFEC_EMR.RES=0 (12-bit mode, no averaging).