Three-phase automotive gate driver operates in ICE and HEV/EVs
An integrated automotive three-phase gate driver unit from STMicroelectronics can be use in conventional and hybrid and electric vehicles (HEVs/EVs). The L9908 operates in 12, 24 or 48V systems.
Dedicated source connections to the high-side and low-side FETs of each half bridge let users configure the output channels independently to drive various types of loads. There are six separate PWM (pulse-width modulation) input pins to allow independent management of the pre-driver stages for different motor-control strategies.
According to ST, high accuracy is assured, with three differential current monitors for ground-referenced measurements and three channels for real-time phase-voltage monitoring.
According to STMicroelectronics, the L9908 simplifies design, saves space, and enhances control of low-voltage fluid pumps, pumps and blowers in ventilation and cooling systems and electronic seat controls. It can be also used in traction inverters for mild-hybrid internal combustion engine (ICE) vehicles and 48V full-electric city cars.
Built-in diagnostics allow use in safety-related systems such as autonomous emergency braking (AEB) and advanced electronic power steering (EPS), simplifying certification according to ISO 26262, the functional safety standard.
Safety features include SPI-programmable dead-time insertion with shoot-through diagnostic and protection, open-load detection, and short-to-ground and short-to-battery diagnostics. There is also an SPI-programmable temperature warning and SPI-readable junction-temperature measurement. Other diagnostics include ground-loss detection, over-voltage and under-voltage detection on the power supply pins and FET-driver supply, system-clock monitoring, SPI window watchdog and a fault-status flag.
The L9908 gate driver can be used in single (12V), dual (24V), and 48V battery applications and has a wide motor supply voltage range from 4.5 to 75V, with the ability to tolerate -14V to 95V on motor-connection pins. The on-chip logic is supplied from an internally generated 3.3V supply and digital I/Os are 3.3 and 5.0V-compatible.
The L9908 is AEC-Q100-qualified and available now, in a thermally enhanced TQFP48 package.