EFM32WG Datasheet, PDF (726/834 Pages) List of Unclassifed Manufacturers – The EFM32WG Wonder Gecko is the ideal choice for demanding 8-, 16-, and 32-bit energy sensitive applications.

• Cascaded Non-inverting PGA
• Two Opamp Differential Amplifier
• Three Opamp Differential Amplifier
• Dual Buffer ADC Driver
• Programmable gain
...the world's most energy friendly microcontrollers
30.3 Functional Description
The three opamps can be configured to perform various opamp functions through a network of muxes.
An overview of the opamps are shown in Figure 30.1 (p. 726) . Two of the three opamps are part of the
DAC, while the third opamp is standalone. The output of OPA0 can be routed to ADC CH0, OPA1 and
various pin outputs. The output of OPA1 can be routed to ADC CH1, OPA2, and various pin outputs. The
output of OPA2 can be routed to ADC CH0, CH5, and various pin output destinations. All three opamps
can also take input from pins. Since OPA0 and OPA1 are part of the DAC, special considerations needs
to be taken when both the DAC Ch0/Ch1 and OPA0/OPA1 are being used. For detailed explanation the
reader is referred to Section 30.3.3 (p. 735) .
Figure 30.1. OPAMP System Overview
POS2
NEG2
POS0
NEG0
POS1
NEG1
DAC
OPA0 Alt ernat ive
outputs
OPA0
OPA0 Main
output
ADC CH0
input mux
OPA2 Main
outputs
OPA0 NEXT
OPA1 Alt ernat ive
outputs
OPA2
ADC CH5
input mux
ADC CH0
input mux
OPA1
OPA1 Main
output
OPA1 NEXT
ADC CH1
input mux
A more detailed view of the three opamps, including the mux network is shown in Figure 30.2 (p. 727)
. There is a set of input muxes for each opamp, making it possible to select various input sources. The
POSSEL mux connected to the positive input makes it possible to select pin, another opamp output,
or tap from the resistor network. Similarly, the NEGSEL mux on the negative input makes it possible
to select pin or a feedback path as its source. The feedback path can be a unity gain configuration, or
selected from the resistor network for programmable gain. The output of the opamp have different sets of
outputs, a main output, an alternative output network and a next output. These outputs make it possible
to route the output to pin, another opamp input, ADC, or into the feedback path. For details regarding
configuring the outputs, the reader is referred to Section 30.3.1.2 (p. 727) . In addition, there is also a
mux to configure the resistor ladder to be connected to vss, pin, or another opamp output.
2013-05-08 - Wonder Gecko Family - d0233_Rev0.50
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