Opamp - Operational Amplifier - Silicon Laboratories EFR32xG14 Wireless Gecko Reference Manual

24. OPAMP - Operational Amplifier

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24.1 Introduction
The opamps are highly configurable general purpose opamps, suitable for simple filters and buffer applications. The 2 opamps can be
configured to support various operational amplifier functions through a network of muxes with possibilities of selecting ranges of on-chip
non-inverting and inverting gain configurations and selecting between outputs to various destinations. The opamps can also be config-
ured with external feedback in addition to supporting cascade connections between two or three opamps. The opamps are rail-to-rail in
and out. A user selectable mode has been added to optimize linearity, in which case the input voltage to the opamp is restricted to a
range between VSS and AVDD-1.2V.
24.2 Features
• 2 individually configurable opamps
• Opamps support rail-to-rail inputs and outputs
• Supports the following functions
• General opamp mode
• Voltage follower unity gain
• Inverting input PGA
• Non-inverting PGA
• Cascaded inverting PGA
• Cascaded non-inverting PGA
• Two opamp differential amplifier
• Three opamp differential amplifier
• Dual buffer ADC driver
• Programmable gain
• Programmable drive strength
• Programmable start delay, warmup and settle time
• Connection to APORT
• Enable / Disable via PRS
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OPAMP - Operational Amplifier
Quick Facts
What?
The opamps are low power amplifiers with a high
degree of flexibility targeting a wide variety of stand-
ard opamp application areas. With flexible gain and
interconnection built-in, they can be configured to
support multiple common opamp functions. All pins
are available externally for filter configurations. Each
opamp has a rail-to-rail input and a rail-to-rail output.
Why?
The opamps are included not only to save energy on
a PCB compared to standalone opamps but also to
reduce system cost by replacing external opamps.
How?
Two of the opamps are made available as part of the
VDAC, while the other opamps are standalone. In
addition to popular differential-to-single ended and
differential-to-differential driver modes, an ADC unity
gain buffer mode configuration makes it possible to
isolate kickback noise. The opamps can also be
configured as a multi-step cascaded PGA, and for all
of the built-in modes no external components are
necessary.
Reference Manual
Rev. 1.1 | 797