Solid State Optronics, Inc. has developed two types of technology which help solid state relays (SSRs) limit the flow of current through their output structures. This application note will attempt to clarify the differences between the two and describe how each one performs.

The AD6C312 is a bi-directional, double-pole, single-throw, normally open multipurpose solid-state relay. It is designed to replace electromechanical relays in general purpose switching applications. The relay consists two integrated circuits, each driving a pair of rugged source-to-source enhancement type DMOS transistors-optically coupled to a light emitting diode.

The TD3052 consists of an AIGaAs LED optically coupled to a Random Phase triac driver chip. The TD3052 provides high input-to-output isolation and is designed to drive high-powered triacs. Typical uses include interfacing logic level control signals to equipment powered from 110Vac and 220CVac lines.

The AD4C213 is composed of two isolated relay; one normally open and one normally closed. Each relay has a bi-directional, single-pole, single-throw contact.

The SLC1600 is a highly advanced linear optocoupler device. The product takes advantage of highly matched transistors used for both a Servo Feedback Loop and a Forward Output Loop. The closely matched transistors provide a high degree of linearity across a wide range of input signal variation.

The SAT400 consists of a phototransistor optically coupled to a pair of light emitting diodes for AC input operation. Optical coupling between the input LEDs and output phototransistor allows for high isolation levels while maintaining low-level AC signal control capability.

The S107-X is a bi-directional, single-pole, single-throw, normally open multipurpose relay. The circuit is composed of one LED on the input side which activates an optically coupled IC on the output-controlling the firing angle of two back-to-back SCRs.

High temperature is a common environmental stress in many solid state relay applications. Application engineers must have a solid understanding of how a relay can be expected to fail if the temperature exceeds the rating of the package. This paper aims to compare the theoretical and experimental failure modes of SCR-output relays vs. MOSFET-output relays at high temperature.

The AD6C311 is a bi-directional, double-pole, single-throw, normally open multipurpose solid-state relay. It is designed to replace electromechanical relays in general purpose switching applications. The relay consists two integrated circuits, each driving a pair of rugged source-to-source enhancement type DMOS transistors-optically coupled to a light emitting diode.

The TD3053 consists of an AIGaAs LED optically coupled to a Random Phase triac driver chip. The TD3053 provides high input-to-output isolation and is designed to drive high-powered triacs. Typical uses include interfacing logic level control signals to equipment powered from 110Vac and 220CVac lines.