TIDUFG5 December   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Insulation Monitoring
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 TIDA-010985 Overview
      2. 2.2.2 Solving for the Unknown Isolation Resistances
      3. 2.2.3 Addressing Large Time Constant Cases
      4. 2.2.4 Prediction Algorithms
      5. 2.2.5 Understanding Error Sources
    3. 2.3 Highlighted Products
      1. 2.3.1 LP-MSPM0G3507
      2. 2.3.2 TPSI2240-Q1
      3. 2.3.3 RES60A-Q1
      4. 2.3.4 TLV9002-Q1
      5. 2.3.5 TPSM33620-Q1
      6. 2.3.6 TPS7A2033
      7. 2.3.7 ISOW1044
      8. 2.3.8 TSM24CA
      9. 2.3.9 TLV431B
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software
    3. 3.3 Test Setup
      1. 3.3.1 Hardware Test Setup
      2. 3.3.2 Software Test Setup
    4. 3.4 Test Results
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 PCB Layout Recommendations
        1. 4.1.3.1 Layout Prints
    2. 4.2 Tools and Software [Required Topic]
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Authors

2.2.1 TIDA-010985 Overview

Figure 2-2 shows the TIDA-010985 analog front end (AFE) key system components as mentioned in the following list:

  1. Mechanical connectors to DC+, DC– and Protected Earth (PE)
  2. The quasi-balanced resistive network providing multiple test resistance combinations (Rsn, R1, Rsp).
  3. TPSI2240 bidirectional solid-state switches (SW1, SW2) to alternate the resistive network
  4. Single-supply inverting amplifier for voltage sensing of VDC– relative to PE. Voltage is scaled down to ADC level (Vn). Required to calculate RisoN and RisoP.
  5. Single-supply voltage buffer for voltage sensing of VDC+ relative to PE. Voltage is scaled down to ADC level (Vp). Required to calculate RisoN and RisoP.
  6. A microcontroller is used to control these switches, sample the analog outputs (simultaneously), and calculate the insulation resistances.
TIDA-010985 TIDA-010985 Simplified Schematic Without Target System Connected Figure 2-2 TIDA-010985 Simplified Schematic Without Target System Connected

Figure 2-3 shows the simplified schematic with the target system connected. The IMD must determine all Riso and Ciso passive values.

TIDA-010985 Simplified Design Schematic With Target System Connected Figure 2-3 Simplified Design Schematic With Target System Connected