1 Operational Amplifier

The Operational Amplifier (OPA) module is a general purpose operational amplifier that is integrated with the microcontroller, making control and configuration simple. Standard operational amplifiers have only a single connection per input to the operational amplifier (op amp), while this module contains a multiplexer that enables four external inputs for each of the inputs. In addition, this module also contains a secondary multiplexer, which enables inputs from the Digital-to-Analog Converter (DAC) modules, an internal programmable resistor ladder, or select reference signals (such as V_DD/2 or V_SS).

The OPA module also integrates a software output control that can be used to force the output of the op amp to V_SS or V_DD, ignoring the inputs to the op amp. In addition, the OPA module has a hardware controlled override, which enables another peripheral to change the output configuration between modes, such as Rail Drive, Forced Unity Gain or Software Configuration, without software intervention.

For ease of use, the OPA module has been integrated with the ADC to enable sampling of the output or the non-inverting input. This feature can be used to create a self-calibration routine. Refer to Input Offset Voltage Calibration Example for more information. When the op amp is not needed, the OPA module can be disabled to save both power and to free the I/O pins that the module controls.