Independent output channels… various types of load drives
Provides automotive motor system diagnosis and protection functions

STMicroelectronics (hereinafter ST) has introduced a gate driver featuring flexible input and output channels to support various applications in conventional vehicles, hybrids, and electric vehicles.

ST released the L9908, an integrated three-phase gate driver unit (GDU) for automobiles that operates at battery input voltages of 12V, 24V, or 48V, on the 5th.

By connecting dedicated sources to the high-side and low-side FETs (Field-Effect Transistors) of each half-bridge, the user can independently configure output channels to drive various types of loads.

In addition, the MOSFET pre-driver can be independently controlled according to various motor control strategies through six individual PWM (Pulse-Width Modulation) input pins.

It ensures high accuracy in motor current and voltage measurement through three differential current amplifiers that measure current based on a ground reference and a three-channel monitor capable of real-time monitoring of the motor's phase voltage, and also provides various diagnostic and protection functions required for the motor system.

The L9908 features high integration, flexibility, and accuracy, simplifying design, saving space, and controlling low-voltage fluid pumps In addition, it improves the control functions of pumps and blowers in ventilation and cooling systems and electronic seats.

It can also be used in traction inverters for mild hybrid internal combustion engine (ICE) vehicles and 48V all-electric city cars.

In addition, the integrated diagnostic function of the L9908 can be used for safety-related systems such as Autonomous Emergency Braking (AEB) and Electronic Power Steering (EPS), simplifying ISO 26262 certification.

Safety features include shoot-through diagnosis and protection functions, SPI programmable dead-time settings, open load detection, ground-side short circuit and battery-side short circuit diagnosis.

It also provides temperature warnings and IC Junction (Tj) temperature measurement functions via SPI. Other diagnostic functions supported include system clock monitoring, SPI window watchdog, and error status flags, along with overvoltage and undervoltage detection of power supply pins and FET driver power supplies, and ground loss detection.

The L9908 gate driver can withstand -14V to 95V at the motor connection pins and provides a wide motor supply voltage range of 4.5V to 7.5V, making it flexible for single (12V), dual (24V), and 48V battery applications. The logic embedded in the chip is powered by an internally generated 3.3V power supply, and the digital I/O is compatible with 3.3V and 5V.