35.3.2.1 MUXPOS - Non-Inverting (+) Input Selection

As shown in Figure 35-1, the non-inverting (+) input of an op amp is connected to an analog multiplexer that allows one input source to be selected out of a variety of input sources. The source selection is configured using the MUXPOS 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 non-inverting input options are available for OPn:
  • INP (OPnINP) - Positive input pin for OPn
  • WIP (OPnWIP) - Wiper from OPn’s resistor ladder
  • DAC - DAC output (DAC and DAC output buffer must be enabled)
  • GND - Ground
  • VDDDIV2 - VDD/2
OP1 has the following additional input available:
  • LINKOUT (OP0OUT) - OP0 output
OP2 has the following additional inputs available:
  • LINKOUT (OP1OUT) - OP1 output
  • LINKWIP (OP0WIP) - Wiper from OP0’s resistor ladder