What is a MOSFET Relay?

MOS FET RELAY DEFINITION

About MOS FET Relays

MOS FET relays are semiconductor relays that use MOS FET for their outputs.
Non-contact relays, mainly used for switching and connecting signals, are used in a wide range of applications, including semiconductor test equipment, measuring instruments, and security equipment.

MOS FET Relay Features

Ultra-small and lightweight SSOP, USOP and other new ultra-small packaging VSON are emerging, which contributes to miniaturization of the entire device.
Low drive current The drive current is about 2 to 15mA under the recommended operating condition (normal). We also have a minimum of 0.2 mA products which contribute to energy saving of whole device.
Longer-life Our MOS FET relays have a non-contact structure using an optical signal transmission method. We have achieved long durability without deterioration of life due to contact friction.
small leakage current Because of its high resistance to external surges and no added snubber circuit, the leakage current is extremely small, typically 1 nA or less in the off state. (G3VM-□GR□,-□LR□,-□PR□,-□UR□)
superior impact resistance Since the internal parts are completely molded and there are no mechanical parts such as movable parts, they are excellent in shock resistance and vibration resistance.
Quiet sound Since there is no switching noise caused by metal contacts unlike machine relays, it contributes to noise reduction of device.
High insulation Since there is no switching noise caused by metal contacts unlike machine relays, they contribute to noise reduction of device.
Precise control of small analog signals Since the dead band is extremely small compared to a triac etc, the input waveform of a small analog signal is converted into an output waveform with little distortion.

MOS FET Relay Types

Product map by MOS FET relay type

Product map by MOS FET relay type

MOS FET Relay Diagram

Basic structures and operating of MOS FET relays

Internal structure

MOS FET relays consist of following three chips:

  1. LED chips
  2. PDA (photodiode array) chip
  3. MOS FET chips
Operational principle

MOS FET relays operate according to the following principles.

  1. The LED lights when the current flows to the input side.
  2. The light from the LED is received by the photodiode array, which generates electricity to convert the light back to a voltage
  3. This voltage passes through the control circuit to become the gate voltage to drive the MOS FET.

MOS FET Relay Application Examples

FA/Industrial equipment

Machine tools, custom power supplies, FA devices (programmable controller/temperature controller/timer)

Application Status output, various signals, small solenoid valve, power supply external output of small motor

Machine tools

Machine tools

Timer

Timer

Test measurement/testers

Semiconductor test equipment (ATE)/semiconductor test interface boards, oscilloscopes, data loggers, I/O boards

Application Measurement signal switching, power supply

ATE(Semiconductor test equipment)

ATE
(Semiconductor test equipment)

Tester

Tester

Security devices

Smoke and gas detectors, home security panels, human body detection sensors and TV doorphones

Application status output, various signal output, small solenoid valve, power supply external output of small light

Smoke and gas detector

Smoke and gas detector

Home security panel

Home security panel

Amusement equipment

paper money discrimination units, game ball and medal lending machines (interposed machine), IT equipment

Application status output, various signals

Gaming machines

Gaming machines