Dusseldorf, Germany: The PS9402 insulated gate bipolar transistor (IGBT) drive optocoupler from Renesas Electronics integrates IGBT protection. It comprises a gallium-aluminium-arsenide (GaAlAs) LED as the light-emitting element, a photodetector IC, and an IGBT protection circuit.
The device is designed to drive IGBTs used in inverter devices for purposes such as motor control. The use of the new optocoupler helps with the design of IGBT peripheral circuits and enables IGBT direct drive up to 1200 V and 100 A.
An optocoupler integrates an LED on the input side, which converts an electric signal into light, and a light-receiving element on the output side, which converts light into an electric signal. It is an optical coupling device that completely isolates the input and output sides electrically by using light for signal transfer.
The inverter circuits in industrial equipment and household appliances use optocouplers to protect the circuits between electronic devices and to shut out noise by electrically isolating the input and output blocks.
General-purpose inverters and inverters for solar power-generation systems reduce environmental impact by cutting carbon-dioxide emissions and reducing power conversion loss to save energy. The inverter circuit comprises a high-voltage circuit block incorporating power devices such as IGBTs or MOSFETs and a control circuit block employing components such as a microcontroller (MCU).
Optocouplers designed for use with IGBTs or MOSFETs are needed to electrically isolate the two circuit blocks. An IGBT drive coupler is typically used for the drive control of an IGBT, but a protection circuit is also needed to safeguard the IGBT.