STMicroelectronics L9945 MOSFET Pre-Drivers
STMicroelectronics L9945 MOSFET Pre-drivers are configurable for low-side, high-side, peak and hold, and H-Bridge load control. The STMicroelectronics L9945 Pre-drivers are designed to comply with the requirements of 12V (passenger vehicle) and 24V (commercial vehicle) battery systems. The L9945 offers PWM-controlled outputs; six can drive safety-relevant loads, and one can be dedicated to actuating safety-relevant loads requiring a dedicated enable pin (EN6).The device can drive up to two loads, requiring a "peak and hold" control strategy, and the driver outputs are protected against short circuit conditions. The L9945 Pre-drivers can control two independent H-Bridges and protect the external MOS in case of an overcurrent event. Each output provides complete diagnostic information such as short to battery, short to ground, and open-load, enabling status to be constantly monitored through dedicated SPI registers.
The L9945 MOSFET Pre-drivers implement 1-8 external transistors, which allow a voltage slew rate to control them during turn ON and turn OFF to improve EMI behavior. The device has a double, redundant, and external disable source available through DIS and NDIS pins to improve safety. The device is configurable via SPI through a 32-bit protocol.
Features
- AEC-Q100 qualified
- 12V and 24V battery systems compliance
- 3.3V and 5V logic compatible I/O
- 8-channel configurable MOSFET pre-driver
- High-side (N-channel and P-channel MOS)
- Low-side (N-channel MOS)
- H-bridge (up to 2 H-bridge)
- Peak & Hold (2 loads)
- Operating battery supply voltage 3.8V to 36V
- Operating VDD supply voltage 4.5V to 5.5V
- All device pins, except the ground pins, withstand at least 40V
- Individual diagnosis for
- Short circuit to battery
- Open load
- Short circuit to ground
- Highly flexible overcurrent sensing implementation
- Possibility of monitoring external MOS drain to source voltage
- Possibility of monitoring the voltage on the external shunt resistor
- 64 programmable overcurrent thresholds independent for each channel
- Ultra-fast output shutdown in case of overcurrent
- Current limitation for H-Bridge configuration
- Programmable gate charge/discharge currents for improving EMI behavior
- 32-bit SPI protocol available for configuration and diagnostics
- Failures latched even if occurred during diagnostics reading
- Daisy chain operation
- SDO protected against overvoltage
- Safety features
- Fast switch off redundant output disabled through two external pins
- Built-in Self Test (BIST) for logic operation
- Hardware Self Check (HWSC) for VDD5 overvoltage comparator
- Configurable Communication Check (CC) watchdog timer available
- Disable feedback through bi-directional pin
- Highly redundant output monitoring through dedicated SPI registers
- 10-bit ADC for battery and die temperature measurements available through SPI
- VDD5 monitoring for over/under voltage
- VPS (battery) monitoring for under-voltage
Block Diagram
