TIDUF39 March   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
    3. 2.3 Highlighted Products
      1. 2.3.1 DAC70502: Dual-Channel, 1-LSB INL, 14-Bit, SPI Voltage-Output Digital-to-Analog Converter (DAC)
      2. 2.3.2 INA818: 35μV Offset, 8nV/√Hz Noise, Low-Power, Precision Instrumentation Amplifier
      3. 2.3.3 OPA192: High-Voltage, Rail-to-Rail Input/Output, 5µV, 0.2µV/°C, Precision Operational Amplifier
      4. 2.3.4 LM5146: 100V Synchronous Buck DC/DC Controller With Wide Duty Cycle Range
  9. 3System Design Theory
    1. 3.1 Constant Current Control Design
    2. 3.2 Constant Current and Voltage Simulation
  10. 4Hardware, Software, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Software Requirements
    3. 4.3 Test Setup
      1. 4.3.1 Constant Current Test Setup
      2. 4.3.2 Constant Voltage Test Setup
    4. 4.4 Test Results
      1. 4.4.1 Current Control Accuracy
      2. 4.4.2 Voltage Control Accuracy
      3. 4.4.3 CC, CV Transformation
      4. 4.4.4 Constant Current Transient Response
      5. 4.4.5 Constant Voltage Transient Response
      6. 4.4.6 Voltage Ripple at Short Circuit
      7. 4.4.7 Tracking DC-DC output
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
    2. 5.2 Tools and Software
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5. 5.5 Trademarks
  12. 6About the Author

2.3.2 INA818: 35μV Offset, 8nV/√Hz Noise, Low-Power, Precision Instrumentation Amplifier

The INA818 is a high-precision instrumentation amplifier that offers low power consumption and operates over a very wide single-supply or dual-supply range. A single external resistor sets any gain from 1 to 10000. This device measures and amplifies a differential voltage that represents output current which acts as feedback to regulate current. With a built-in super-beta input transistor, this device provides low-input offset voltage, offset voltage drift, input bias current, input voltage, and current noise.

Important features include:

  • Gain drift: 5ppm/°C (G = 1), 35ppm/°C (G > 1) (maximum)
  • Bandwidth: 2MHz (G = 1), 270kHz (G = 100)
  • Inputs protected up to ±60V
  • Common-mode rejection: 110dB, G = 10 (minimum)