EFM32WG Datasheet, PDF (734/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

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DACn_OPA2MUX. In addition the OPA2POSSEL must be set to 0PATAP. The OPA2 output can be
configured by configuring the OUTPEN and OUTMODE bit-field.
Figure 30.10. Three Op-amp Differential Amplifier Overview
V2
+
OPA0
-
R1
R2
V1
+
OPA1
-
+
OPA2
-
VOUT
VOUT= (V2-V1)R2/R1
R1
R2
The gain values for the Three Opamp Differential Amplifier is determined by the combination of the gain
settings of OPA0 and OPA2. The 3 different gain values available, 1/3, 1 and 3, can be programmed
as shown in the table below.
Table 30.9. Three Opamp Differential Amplifier Gain Programming
Gain
1/3
1
3
OPA0 RESSEL
4
1
0
OPA2 RESSEL
0
1
4
Table 30.10. Three Opamp Differential Amplifier Configuration
OPA
OPA0
OPA0
OPA0
OPA1
OPA1
OPA1
OPA1
OPA2
OPA2
OPA2
OPA bit-fields
POSSEL
NEGSEL
RESINMUX
POSSEL
NEGSEL
RESINMUX
NEXTOUT
POSSEL
NEGSEL
RESINMUX
OPA Configuration
POSPAD
UG
DISABLE
POSPAD
UG
DISABLE
1
OPATAP
OPATAP
OPA1INP
30.3.2.9 Dual Buffer ADC Driver
It is possible to use OPA0 and OPA1 to form a Dual Buffer ADC driver as shown in Figure 30.11 (p.
735) . Both opamps used can be configured in the same way. The positive input is configured by
setting the 0PAxPOSSEL to PAD and the negative input can be connected to the resistor ladder by
setting OPATAP in DACn_OPAxMUX. The output from the opamps can be configured to connect to the
ADC by setting OUTMODE to ALT or ALL in DACn_OPAxMUX.
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
734
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