8.3 Feature Description

8.3.1 Gain Control

The PGA855 uses three pins to set the amplifier gain. These gain select pins are set with respect to DGND.

This configuration simplifies design when compared to programmable-gain amplifiers requiring an SPI or other

digital interface options for gain changes. Figure 8-1 shows the gain-setting block diagram. Table 8-1 lists the

gain options. Any gain select pin that is not driven by an external source is automatically biased at DGND using

internal pulldown options.

Gain Decoder

A2

A1

A0

D

GND

Figure 8-1. PGA855 Gain Setting Block Diagram

Table 8-1. Gain Options

A2:A0

GAIN

000

0.125

001

0.25

010

0.5

011

1

100

2

101

4

110

8

111

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PGA855

SBOSAE0B – APRIL 2023 – REVISED SEPTEMBER 2023

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