SLVUDF7 October   2025

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Electrostatic Discharge Caution
    3. 1.3 Kit Contents
    4. 1.4 Specification
    5. 1.5 Device Information
    6. 1.6 Hot Surface Warning
  8. 2Hardware
    1. 2.1 Setup and Connections
    2. 2.2 Jumper Settings
    3. 2.3 Power-Supply Connections
    4. 2.4 Analog Input and Output Connections
    5. 2.5 Reference Input
    6. 2.6 Digital Input Pins and Gain Control
    7. 2.7 Modifications
  9. 3Hardware Design Files
    1. 3.1 PCB Layout
    2. 3.2 Schematic
    3. 3.3 Bill of Materials
  10. 4Additional Information
    1. 4.1 Trademarks
  11. 5Related Documentation

2.6 Digital Input Pins and Gain Control

The PGA848 provides eight decade (scope) gain settings, from an attenuating gain of 0.5V/V to a maximum of 100V/V. The gain is controlled by three digital selection pins: A2, A1, and A0. By default, the PGA848 is configured to a gain of 0.5V/V.

The evaluation board provides shunt jumpers J10, J11, and J12 to set the PGA848 gain-control selection pins. Table 2-4 lists the gain-control options. To set the gain-control pin high, install the shunt on the corresponding jumper. To set the gain-control pin low, remove the shunt jumper.

Table 2-4 PGA848EVM Gain Control

A2

Jumper J10

Connector J15.1

A1

Jumper J11

Connector J15.2

A0

Jumper J12

Connector J15.3

PGA848 Gain (V/V)

0 (Open)0 (Open)0 (Open)0.5
0 (Open)0 (Open)1 (Shunt)

1

0 (Open)1 (Shunt)0 (Open)

2

0 (Open)

1 (Shunt)

1 (Shunt)

5

1 (Shunt)

0 (Open)

0 (Open)

10

1 (Shunt)0 (Open)1 (Shunt)

20

1 (Shunt)

1 (Shunt)

0 (Open)

50

1 (Shunt)1 (Shunt)1 (Shunt)100

Alternatively, the A2, A1, and A0 digital pins can be driven externally through connector J15. Any pin that is not driven by an external source, or any shunt that is left open, is biased at DGND using pull-down resistors. Figure 2-9 shows the gain-setting block diagram.

PGA848EVM PGA848EVM Gain ControlFigure 2-9 PGA848EVM Gain Control