R1
R2
V2
-
+
-
+
V1
VDIFF=(V2-V1)R2/R1
OPA0
OPA1
R1
R2
V2
-
+
-
+
V1
VDIFF=(V2-V1)R2/R1
OPA1
OPA2
Figure 24.9. Two Op-amp Differential Amplifier Overview
Table 24.10. OPA0/OPA1 Differential Amplifier Configuration
OPA
OPA Bitfields
OPA Configuration
OPA0
POSSEL
POSPAD0, APORT[1-4]X
OPA0
NEGSEL
UG
OPA0
RESINMUX
DISABLE
OPA1
POSSEL
POSPAD1, APORT[1-4]X
OPA1
NEGSEL
OPATAP
OPA1
RESINMUX
OPANEXT
Table 24.11. OPA1/OPA2 Differential Amplifier Configuration
OPA
OPA Bitfields
OPA Configuration
OPA1
POSSEL
POSPAD1, APORT[1-4]X
OPA1
NEGSEL
UG
OPA1
RESINMUX
DISABLE
OPA2
POSSEL
POSPAD2, APORT[1-4]X
OPA2
NEGSEL
OPATAP
OPA2
RESINMUX
OPANEXT
24.3.4.8 Three Opamp Differential Amplifier
This mode allows the three opamps to be internally configured to form a three opamp differential amplifier as shown in
24.10 Three Op-amp Differential Amplifier Overview on page 809
. For both OPA0 and OPA1, the positive input can be connected to
any input by configuring the OPA0 POSSEL and OPA1 POSSEL bitfields in VDACn_OPA0_MUX and VDACn_OPA1_MUX, respectiv-
ley. The OPA0 and OPA1 feedback paths must be configured for unity gain by setting the OPA0 NEGSEL and OPA1 NEGSEL bitfields
to UG in VDACn_OPA0_MUX and VDACn_OPA1_MUX respectivley. In addition the OPA0 RESINMUX and OPA1 RESINMUX bitfields
must be set to DISABLED. The OPA1 output must be connected to OPA2 by setting RESINMUX to OPANEXT in VDACn_OPA2_MUX
and the OPA2 POSSEL must be set to OPATAP. The OPA2 output is configured by the DACn_OPA2_OUT register.
Reference Manual
OPAMP - Operational Amplifier
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