Pre-driver IC for electric drives integrates photocoupler

April 28, 2016 // By Christoph Hammerschmidt
Inverters in electric and hybrid powertrains in most cases use opto-isolated IGBT pre-driver circuits to separate high voltage for the motors from the electronic control crcuitry. Toshiba Electronics Europe now has developed a photocoupler IC that addresses this type of applications.

The TB9150FNG integrates a photocoupler that secures high-level isolation between control (the primary side) and drive (the secondary side). It also incorporates a highly precise IGBT temperature detection function, a flyback transformer controller and a short circuit detection function (current sense and DESAT 2 monitor) that all contribute to system downsizing.


Supplied in an SSOP48 package, the TB9150FNG measures just 10.4mm x 12.5mm x 2.0mm. Operating temperature range is -40°C to 125°C.


Key Features

  • Optical isolation function: Electrical isolation and high-withstand voltage isolation of 2500Vrms (AC, one minute) are achieved by a built-in photocoupler for communication between the primary and secondary sides. The perfect isolation this achieves secures a high tolerance to exogenous noise, such as that caused by electro-magnetic susceptibility


  • Highly precise temperature detection function: The new IC has the constant current source for a temperature sense diode incorporated in IGBT and the AD converter. It measures voltage inside the temperature sense diode with high accuracy, allowing temperature to be precisely calculated. Performance can be optimized by monitoring the IGBT’s operating temperature, contributing both to downsizing of the IGBT and improved fuel consumption by electric and hybrid vehicles


  • Built-in flyback transformer control circuit for the power supply. A flyback transformer control circuit in the primary side supplies power to the secondary side while maintaining isolation. It also has a soft-start function that secures smooth start-up when turning on power to the circuit, avoiding current overload.


  • Various built-in abnormality detection circuits and protection circuits. The power supply, output, current and voltage of the IGBT are all monitored. Information on any detected abnormality is transferred to the main controller via an SPI interface. A dedicated circuit provides protection against any abnormality with the potential to destroy the IC and IGBT.


  • Based on AEC-Q100 standards.

Supplied in an SSOP48 package, the TB9150FNG measures just 10.4mm x 12.5mm x 2.0mm. Operating temperature range is -40°C to 125°C.