STMicroelectronics' automotive-grade gate drivers increase motor control flexibility

China, April 15, 2022 - STMicroelectronics' L9908 highly integrated automotive-grade three-phase gate driver unit (GDU) supports 12V, 24V or 48V automotive power systems , has flexible input and output channels, and can be used in a variety of applications in traditional gasoline vehicles and hybrid/electric new energy vehicles.

The L9908 provides dedicated source pins for connecting the upper and lower bridge arm FETs (field effect transistors) for each half-bridge, allowing users to configure the output channels separately to drive different types of loads. In addition, the L9908 provides six independent PWM (pulse width modulation) input pins that can manage the pre-driver circuit separately to implement different motor control strategies.

Three differential current monitors for measuring ground current and three phase voltage real-time monitoring channels ensure monitoring accuracy . The diagnostic protection functions are also very rich.

In applications such as low-pressure liquid pumps, air pumps and blowers in ventilation and cooling systems, and electric seat control devices, the highly integrated, flexible and accurate L9908 can simplify design, save space and improve control accuracy. The driver can also be used to design power motor inverters for mild hybrid vehicles (ICE) and 48V pure electric vehicles.

With built-in diagnostic capabilities, the L9908 can also be used for safety systems such as automatic emergency braking (AEB) and advanced electric power steering (EPS), simplifying the ISO 26262 standard certification process.

Safety features include SPI-set dead time insertion and shoot-through short-circuit diagnostic protection; open load detection, short-circuit to ground diagnosis, short-circuit to battery diagnosis; temperature warning can be set and junction temperature measurement data can be read through the SPI bus. Other diagnostics include ground loss detection, overvoltage and undervoltage detection of power pins and FET driver power; system clock monitoring, SPI window watchdog and fault status flag.

The L9908 gate driver offers high application flexibility in single-battery (12V), dual-battery (24V) and 48V automotive battery systems, as the motor power pins can tolerate a wide voltage range of 4.5V to 75V, and the motor connection pins can tolerate voltages from -14V to 95V. The on-chip logic circuit uses an internal 3.3V power supply, and the digital I/O ports are compatible with 3.3V and 5V logic levels.

The L9908 is AEC-Q100 qualified and automotive grade and is available now in a thermally improved TQFP48 package. For more information and pricing, please contact your local ST sales office.