58.8 AFE Characteristics

Electrical data are in accordance with an operating temperature range from -40°C to +105°C unless otherwise specified.

VREFP is the positive reference of the AFE. The VREFN pin must be connected to ground.

DAC1 and DAC0 provide an analog output voltage (V_DAC) in the range [0 : VREFP] with an accuracy equal to 10 bits. The DAC output voltage is single-ended and is used as a reference node by the sampling stage S/H0 and S/H1 (Sample-and-Hold PGA), relative to the single-ended input signal being sampled on the selected channel.

As a consequence, programming the DAC output voltage offers a capability to compensate for a DC offset on the input signal being sampled. DC offset compensation is effective in single-ended operation and is not effective in fully differential operation.

During fully differential operation, the DAC10 output voltage can be programmed at VREFP/2, by using the 10-bit code 512. The DAC value does not affect the AFE output code.

VREFP/2 on DAC0 and DAC1 is not automatically set and must be programed as the code 512 into the channel corresponding DAC0 and DAC1.

The following figures illustrate the architecture of the AFE in Single-ended and in Differential modes.