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

4.2.1.1 Lower EMI

Photo relays can have a lower EMI rating than capacitive/inductive based relays. This is because photo relays do not need to modulate or demodulate signal and power across the isolation barrier, Instead, photo relays emit a constant light output from the LED to the sensor.