Figure 173. Pga Mode, Non-Inverting Gain Setting (X2/X4/X8/X16/X32/X64) Or Inverting Gain Setting (X-1/X-3/X-7/X-15/X-31/X-63) With Filtering; Figure 174. Example Configuration - ST STM32G4 Series Reference Manual

Operational amplifiers (OPAMP)
Figure 173. PGA mode, non-inverting gain setting (x2/x4/x8/x16/x32/x64)
VINP4 or DACx_CHy
Allows optional
low-pass
filtering
1. opamp_out can be redirected internally to an ADC channel by setting OPAINTOEN bit.
In this case, the I/O on which is mapped the OPAMPx_VOUT is free and can be used for another purpose.
VINP
24.3.6 OPAMP PGA gain
When the OPAMP is configured in PGA mode, the gain can be programmed to x2, x4, x8,
x16, x32, x64 in non-inverting configuration and x-1, x-3, x-7, x-15, x-31, x-63 for inverting
configuration.
When the OPAMP is configured in non-inverting mode, the gain solely depends on internal
resistive divider. When it is configured as inverting mode, Gain factor is defined not only the
on chip feedback resistor but also the signal source output impedance. If signal source
output impedance is not negligible compare to the input feedback resistance of PGA, it will
create the gain error.
752/2083
or inverting gain setting (x-1/x-3/x-7/x-15/x-31/x-63) with filtering
STM32
VINP0
VINP1
VINP2
VINM1
VINM0
(1)
VOUT

Figure 174. Example configuration

+
-
VINM1
VINM0
Bias voltage
Gain:x2, x4, x8, x16, x32, x64
+
-
Equivalent to
VOUT
Bias voltage
or
Input signal
RM0440 Rev 1
VINP
+
-
VINM0
VINM1
Gain:x-1, x-3, x-7, x-15
RM0440
(1)
opamp_out
MSv48045V1
VOUT
MSv48044V1