35.3.2.2 MUXNEG - Inverting (-) Input Selection

As shown in Figure 35-1, the inverting (-) input of an op amp is also connected to an analog multiplexer that allows one of a variety of input sources to be chosen. The selection is configured using the MUXNEG bit field of the Op Amp n Input Multiplexer (OPAMP.OPnINMUX) register. If the OPnINMUX register is changed while the OPn output is enabled, a glitch will occur on the output signal due to the opening and closing of analog switches, and some time will elapse before the output settles to the new value.

The following inverting input options are available for OPn:
  • INN (OPnINN) - Negative input pin for OPn
  • WIP (OPnWIP) - Wiper from OPn’s resistor ladder
  • OUT (OPnOUT) - OPn output
  • DAC - DAC output (DAC and DAC output buffer must be enabled)