SLVAFU8 July   2024 TPSI2072-Q1 , TPSI2140-Q1 , TPSI3050 , TPSI3050-Q1 , TPSI3052 , TPSI3052-Q1 , TPSI3100 , TPSI3100-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2What Are Solid-State Relays?
    1. 2.1 History
      1. 2.1.1 Electromechanical Relays
      2. 2.1.2 Solid-State Relays
    2. 2.2 Isolation Technologies
      1. 2.2.1 Isolation Specifications
    3. 2.3 Relay Evolution
  6. 3Failure Mechanisms
    1. 3.1 Arcing in an Electromechanical Relay
    2. 3.2 Photo-degradation in Photo Relays
    3. 3.3 Partial Discharge
    4. 3.4 Time-Dependent Dielectric Breakdown in Capacitive and Inductive Isolation
  7. 4Electromechanical vs. Photo vs. Capacitive or Inductive
    1. 4.1 Electromechanical Relays
      1. 4.1.1 Advantages
        1. 4.1.1.1 No Leakage Current
      2. 4.1.2 Limitations
        1. 4.1.2.1 Switching Speed
        2. 4.1.2.2 Package Size
    2. 4.2 Photo or Optical Relays
      1. 4.2.1 Advantages
        1. 4.2.1.1 Lower EMI
      2. 4.2.2 Limitations
        1. 4.2.2.1 Limited Temperature Range
    3. 4.3 Capacitive or Inductive Based Relays
      1. 4.3.1 Advantages
        1. 4.3.1.1 Auxiliary Power
        2. 4.3.1.2 Bidirectional Communication
      2. 4.3.2 Limitations
        1. 4.3.2.1 EMI
    4. 4.4 Overall Comparison
  8. 5Summary
  9. 6References

2.2.1 Isolation Specifications

Solid-state relays typically have an isolation barrier between the primary and secondary sides of the device that can be achieved with various insulation materials. Refer to Table 2-1 for more information.

Table 2-1 Isolation Technology Specification Comparison
Isolation Type Insulation Material Dielectric Strength (1s) Operating Temperature
Optical Isolation Epoxy or Polyimide

approximately 20VRMS / µm

approximately 300VRMS / µm

 -40°C - 85°C
Inductive Isolation Laminate or Polyimide approximately 300VRMS / µm -40°C - 125°C
Capacitive Isolation Silicon Dioxide approximately 500VRMS / µm -40°C - 125°C

To learn more about the internal topologies of optical, capacitive, and inductive isolation, please reference Addressing High-Voltage Design Challenges With Reliable and Affordable Isolation Technologies.