Application Note 1036

“ Small signal Solid State Relays”

http://cp.literature.agilent.com/litweb/pdf/5965-5980E.pdf

Introduction:

Traditionally, isolated control of signal paths has been provided by the Electro-Magnetic Relay (EMR). The purpose of this application note is to present an alternative, the Solid State Relay (SSR), and to describe some of the ways in which the SSR can be used.

Application Note 1047

“Low On-Resistance Solid-State Relays For High-Reliability Applications”

http://cp.literature.agilent.com/litweb/pdf/5091-4502E.pdf

Introduction:

In military, aerospace, and commercial applications, the high performance, long lifetime, and immunity to shock and vibration give solid state relays distinct advantages over electromechanical relays. The

HSSR-7110 family of hermetically sealed power MOSFET optocouplers operate exactly like single-pole, normally-open, solid-state relays (SSR). Therefore, from here on, they will be referred to as SSRs. Each SSR in the HSSR-7110 family contains a light-emitting diode (LED) optically coupled to a high voltage circuit. When a control current flows through the input terminals of the SSR, the LED emits light onto a photodiode array. This photodiode array, illustrated in Figure 1, generates sufficient voltage and current to operate a FET driver circuit and also to drive the gate-to-source voltages above the thresholds of the two output MOSFETs. This application note describes the main characteristics of the HSSR-7110, suggests various control drive circuits, and discusses the use of this SSR with different types of loads. Additional information regarding SSRs and their applications can be found in Agilent Technologies’ Application Notes 1036 and 1046.

Application Note 1074

“Optocoupler Input-Output Endurance Voltage”

http://cp.literature.agilent.com/litweb/pdf/5965-5977E.pdf

Introduction:

A major concern of circuit designers is the reliability of an optocoupler when subjected to repeated and long-term, high-voltage stress between its input and output. Most of the technical data on optocouplers adequately address the capability of an optocoupler to withstand one-time high-voltage transients, but they do not adequately address the issues of: a) how long one can apply a steady state ac or dc voltage between the input and output of the optocoupler before degrading the semiconductors

or the insulation inside the optocoupler, and b) how often one can apply high-voltage transients before degrading the optocoupler.

Application Note 1399

“Maximizing the Life Span of Your Relays”

http://cp.literature.agilent.com/litweb/pdf/5988-6917EN.pdf

Introduction:

Electromechanical relays can be used as actuators, as switches to route power to electrical devices, or for signal routing within a device or between different instruments. In data acquisition applications, relays are used to connect multiple transducers to a single measuring device. Most electromechanical relays are driven electromagnetically. A magnetic flux is generated by passing current through a coil. This magnetic flux causes an armature to move, and the movement causes isolated electrical contacts to open or close, thus making or breaking electrical connections. As with all mechanical devices, relays eventually wear out. If you

use the right relays for the type of measurements you are making and derate them appropriately, you can protect your relays against early failure and prevent damage to your test instruments.