Automotive 3-phase motor gate driver

Automotive 3-phase motor gate driver unit for BLDC motors

Designed to be the ST’s first gate driver unit (GDU) for automotive to support up to 48 V battery applications.

The L9908 is a gate driver unit (GDU) able to control 6 N-channel FETs for brushless motors in automotive applications up to 48 V batteries. Each one of the 3 half-bridge driver channels (HS/LS couples) can be independently configured.

Through 6 dedicated parallel inputs, the pre-driver stages can be controlled independently supporting duty cycle operations from 0% to 100% and allowing to implement all kinds of electric motor control strategies. A dedicated combination of regulators, charge pumps and bootstrap circuits makes the L9908 suitable for use in passenger, commercial, hybrid and energy-efficient vehicles.

To guarantee high-performance control of brushless motors, the L9908 is equipped with 3 independent high-accuracy current monitor channels with SPI-configurable input differential voltage ranges for ground referenced current measurements.

A 32-bit out-of-frame SPI slave interface is implemented for communication up to 10 MHz between the L9908 and the microcontroller. It allows advanced control and diagnostics of the device and enables generic software development. Moreover, the L9908 implements diagnostics on external and internal supplies, ground level, and internal temperature.

Key features

10 year longevity


  • VDH motor supply voltage range from 4.5 to 75 V for working in single (12 V systems), double (24 V systems) and 48 V battery applications
  • 6 separate N-channel FET pre-drivers (dedicated source connection to each FET, the device can withstand -14 V to 95 V on motor connection pins, 0% to 100% duty cycle operation support, dedicated PWM input pin for each gate driver)
  • 3 differential high-accuracy current monitors for ground referred current measurements
  • 3 real-time phase voltage monitor channels
  • Protection and supervision features including current monitor, open-load and overcurrent, thermal warning and thermal shutdown, etc.
  • 32-bit, 10 MHz SPI interface with 5-bit CRC and 1-bit frame counter for internal settings, self-test and full protection and diagnostics (SPI programmable diagnostics and protection in on-state, SPI programmable dead time protection, SPI programmable diagnostic and protection in off-state, over-temperature diagnostic and protection, SPI readable Tj measurement, ground loss diagnostics, over-voltage and under-voltage diagnostics on power supply pins and FET driver, SPI Window Watchdog, fault status flag output, etc…)
  • Full ISO 26262 compliant and ASIL-D systems ready

Key applications

Electronic power steering (EPS)
HVAC (Heating, Ventilation, and Air Conditioning) blowers and fans
Engine cooling fans
Engine cooling fans

Recommended resources

Specific CAN-controlled brushless motor evaluation board based on SPC560P and L9908

Evaluation board based on SPC560P Pictus 32-bitMCU
and L9908 gate driver

Evaluation board based on SPC560P Pictus 32-bitMCU
and L9908 gate driver L9908 with BLDC motor included 


Design considerations for using the L9908 automotive 3-phase motor gate driver unit (GDU)
Application note

This application note explains the various features and functions of the L9908 GDU. In addition to PCB layout considerations, there is information on evaluating your design using the L9908 development platform and using two L9908 GDUs in a dual device system.


STMicroelectronics’ automotive gate driver boosts motor-control flexibility
Press release

This press release describes the innovative features of the L9908 gate driver unit (GDU) and how its flexible input and output channels fulfil numerous applications in conventional and hybrid/electric vehicles.



L9908, 48 V Batteries Applications and 3 Current Sensors Usher an Awesome Generation of Cars
Blog post

The L9908 is ST’s first gate driver unit (GDU) for automotive to support 48 V batteries. The new device thus meets the latest power requirements that stem from the popularization of hybrid and energy-efficient vehicles.

Boost motor control flexibility in automotive applications with ST's latest gate driver unit
On-demand webinar

Learn how our newest automotive gate driver unit (GDU) can be used for implementing a wide range of motor control strategies in conventional and hybrid/electric vehicles

Webinar overview
  • Overview of motor control in automotive applications
  • Detailed operation of the L9908, 3-phase motor gate driver unit
  • Unique and innovative features
  • Applications and use cases