SLVUDF8 November   2025 PGA854

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
      1. 1.1.1 Electrostatic Discharge Caution
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
      1. 1.4.1 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 Digital Input Pins and Gain Control
    6. 2.6 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

2.5 Digital Input Pins and Gain Control

The PGA854 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 PGA854EVM is configured to a gain of 0.5V/V.

The evaluation board provides shunt jumpers J10, J11, and J12 to set the PGA854 gain-control selection pins. Table 2-4 lists the gain-control options. To set the gain-control pin high (1), install the shunt on the corresponding jumper. To set the gain-control pin low (0), remove the shunt jumper.

Table 2-4 PGA854EVM Gain Control
A2
Jumper J10
Connector J15.1		A1
Jumper J11
Connector J15.2		A0
Jumper J12
Connector J15.3		PGA854 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 pulldown resistors. Figure 2-8 shows the gain-setting block diagram. J10, J11, and J12 should be unpopulated if driving the gain externally through connector J15.

PGA854EVM PGA854EVM Gain ControlFigure 2-8 PGA854EVM Gain Control