44.6.10.7 Instrumentation Amplifier

In this mode, OPAMP0 and OPAMP1 are configured as voltage followers. The OPAMPCTRLx register can be configured as follows:

Table 44-9. Instrumentation Amplifier Configuration
MUXPOS MUXNEG RES1MUX POTMUX RES2VCC RES2OUT RES1EN ANAOUT
OPAMP0 0000 011 010 010 0 1 1 0
OPAMP1 0000 011 011 000 0 0 0 0
OPAMP2 0111 001 010 010 0 1 1 0

The resistor ladders associated with OPAMP0 and OPAMP2 must be configured as follows in order to select the appropriate gain:

Table 44-10. Instrumentation Amplifier Gain Selection
OPAMPCTRL0.POTMUX OPAMPCTRL2.POTMUX GAIN
0x7 Reserved Reserved
0x6 0x0 1/7
0x5 Reserved Reserved
0x4 0x1 1/3
0x3 Reserved Reserved
0x2 0x2 1
0x1 0x4 3
0x0 0x6 7
Note: Either the DAC or GND must be the reference, selected by the OPAMPCTRL0.RES1MUX bits. Refer to the OPAMP Control 'x' register (OPAMPCTRL44.8.3 OPAMP Control x) for details.
Figure 44-8. Instrumentation amplifier