STMicroelectronics’ L9908 integrated three-phase gate driver for automotive unit (GDU) is able to operate in 24V, 12V or 48V systems . It has multiple output and input channels that can be used for a variety of applications in both hybrid and conventional vehicles.
Connecting the source to the low- and high-side FETs (field-effect transistors) of each half-bridge lets users set up the output channels to control different types of loads. Additionally, six distinct PWM (pulse-width modulation) input pins permit independent control of the pre-driver stage to control different motors.
Accuracy is assured thanks to three different current monitors to measure ground-referenced currents and three channels that allow real-time phase voltage monitoring. Additionally, there is a comprehensive range of diagnostic and security options.
Through combining high integration as well as flexibility and precision The L9908 reduces the complexity of design, reduces space and improves the control of low voltage fluid blowers, pumps, and pumps in cooling and ventilation systems, as well as electronic control of seats. It is also utilized in traction inverters to mild hybrid internal combustion engine (ICE) vehicles as well as 48V electric city cars.
Additionally, the L9908’s built-in diagnostics are able to be used in safety-related devices such as autonomous emergency brake (AEB) or advanced electronic power steering (EPS) which makes it easier to obtain certification as per ISO 26262.
The security features include dead-time insertion that can be programmed by SPI with shoot-through diagnostics and security as well as open-load detection and short-to-battery and short-to-ground diagnostics. Also, SPI-programmable temperature alarm and SPI-readable junction-temperature measurements. Other diagnostics include ground loss detection in the form of over-voltage and under-voltage detection at the pins for power supply as well as FET-driver supply monitoring and SPI window watchdog and an error-status flag.
The ability to utilize this L9908 gate driver with single (12V) or dual (24V) and 48V battery applications stems due to its large motor supply voltage range of 4.5V up to 75V, as well as the capability to tolerate -14V-95V on the motor-connection pins. The on-chip logic comes via an internally generated 3.3V supply, as well as digital I/Os that are 3.3Vas well as 5V-compatible.