SBOU316A September   2024  – June 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 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
  8. 2Hardware
    1. 2.1 EVM General Overview
    2. 2.2 Setup and Connections
    3. 2.3 Power Requirements
    4. 2.4 Jumper and Vref Input Information
    5. 2.5 Test Points
    6. 2.6 Adjusting INA630 Gain
  9. 3Hardware Design Files
    1. 3.1 Schematics
    2. 3.2 PCB Layouts
    3. 3.3 Bill of Materials (BOM)
  10. 4Additional Information
    1. 4.1 Trademarks
  11. 5Revision History

2.6 Adjusting INA630 Gain

The default gain of the INA630EVM is 201V/V (Gain = R4/R3 + 1 = 20k/100 + 1 = 201V/V). The gain can be adjusted by replacing R3 AND R4 (0805 footprint) with the desired resistor ratio. Example resistor ratios are listed in Table 2-1, and more information can be found in Detailed Description section of INA630 data sheet.

Table 2-1 Examples for Feedback Resistor Values (0.05%)
DESIRED GAIN R3 (Ω) (0.05%) R4 (Ω) (0.05%) GAIN ERROR (WORST-CASE) (%)
20 1k 18.88k 0.5
50 1k 49.28k 0.28
80 1k 78.67k 0.23
100 1k 98.81k 0.09
120 1k 118.35k 0.54
150 1k 148.6k 0.24
200 1k 198.1k 0.4
500 1k 498.8k 0.01
1000 1k 1M 0.1

Alternatively, the gain can be set using the RES11A resistor network. This resistor network has the advantage of excellent ratio accuracy (0.05% maximum), and an excellent divider temperature coefficient (2ppm/°C maximum). Achieving this level of accuracy without using a matched resistor network is challenging. The RES11A package contains two resistor networks. To double the gain range the input resistors are placed in parallel (G = Rg/(Rin || Rin) + 1). The PCB location and wiring of the RES11A is shown in Figure 2-5.

INA630EVM Using RES11A to Set Gain Figure 2-5 Using RES11A to Set Gain