41.6.10.7 Instrumentation Amplifier
In this mode, OPAMP0 and OPAMP1 are configured as voltage followers. The OPAMPCTRLx register can be configured as follows:
MUXPOS | MUXNEG | RES1MUX | POTMUX | RES2VCC | RES2OUT | RES1EN | ANAOUT | |
OPAMP0 | 000 | 010 | 11 | 010 | 0 | 1 | 1 | 0 |
OPAMP1 | 000 | 010 | 11 | 000 | 0 | 0 | 0 | 0 |
OPAMP2 | 110 | 001 | 10 | 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:
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 OPAMPCTRL0, OPAMPCTRL1 and OPAMPCTRL2 for details.