TIDUEZ1 March   2021

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Multichannel SSR with Independent Isolation Between SSR Channels
      2. 2.2.2 Design Challenge With Single Isolation
      3. 2.2.3 Multichannel SSR Drive With Single Isolation Multichannel Digital Isolator
      4. 2.2.4 Need of High-Impedance Voltage Translator
      5. 2.2.5 Design to Minimize Cross-Coupling and MOSFET Gate Pick up Due to Other SSR Switching
      6. 2.2.6 Schematic: Design of Gate-Drive Circuit
        1. 2.2.6.1 Calculation of Gate-Driver Power Consumption
      7. 2.2.7 Schematic: Digital Isolator Circuit
      8. 2.2.8 Schematic: 3.3 V to 10V_ISO, 5V_ISO Power Supply
    3. 2.3 Highlighted Products
      1. 2.3.1 ISO7760
      2. 2.3.2 ISO7740
      3. 2.3.3 ISO7041
      4. 2.3.4 CSD19538Q2
      5. 2.3.5 CSD17382F4
      6. 2.3.6 TPL7407LA
      7. 2.3.7 TLV760
      8. 2.3.8 TLC555
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 Test Equipment Needed to Validate Board
      2. 3.1.2 Test Conditions
      3. 3.1.3 Test Procedure
    2. 3.2 Test Setup
    3. 3.3 Test Results
      1. 3.3.1 Functional Tests
      2. 3.3.2 Overcurrent Testing With External Fuse
      3. 3.3.3 Surge Testing
      4. 3.3.4 Multichannel SSR Driven From Two 24-VAC Transformers
      5. 3.3.5 Alternate SSR Topology for High Voltage
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Documentation Support
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author

1.1 Key System Specifications

Table 1-1 Key System Specifications
PARAMETER SPECIFICATIONS DETAILS
AC load voltage (RMS) 24 V Scalable with component selection
Load current (RMS) 1 A Scalable with component selection
MCU side voltage 3.3 V Works with 5-V MCU voltage, as well
Quiescent current per SSR channel (MCU side) 0.02–4 mA Based on the turn on and turn off speed
SSR turn on time 15–300 µs Adjustable
SSR turn off time 15–300 µs Adjustable
Board size per SSR 60–80 mm2 Based on the turn on and turn off speed
Surge specification 1.2 kV Using a 40-V MOV onboard
Operating temperature –10°C to 70°C