L9945TR [STMicroelectronics]

Product Overview

The STMicroelectronics L9945TR is an automotive fully configurable 8-channel MOSFET pre-driver designed for controlling high-side, low-side, peak & hold, and H-Bridge load configurations in 12V and 24V vehicle electrical systems. It belongs to STMicroelectronics’ automotive power management IC portfolio and is optimized for driving external MOSFETs used in automotive actuators, motors, relays, and other inductive or resistive loads. 

The L9945TR integrates eight configurable output channels, programmable gate charge/discharge currents, advanced diagnostic functions, SPI communication, overcurrent protection, and safety monitoring features. It supports multiple load-control architectures, including up to two independent H-Bridges and peak & hold control for applications such as fuel injectors and solenoid actuators. 

Designed for automotive-grade systems, the device is AEC-Q100 qualified and supports operating battery voltages from 3.8V to 36V, making it suitable for passenger vehicles, commercial vehicles, and safety-critical automotive electronic systems.

Part Number Breakdown

L9945TR

Key parameters:

Competitive Advantages

Comparison With Alternative Automotive MOSFET Driver Solutions

The STMicroelectronics L9945TR is positioned as a high-flexibility automotive MOSFET pre-driver solution for vehicle manufacturers and Tier-1 suppliers requiring configurable load control, advanced diagnostics, safety features, and reliable operation in demanding automotive environments.

Key Features

1. Eight-Channel Configurable MOSFET Pre-Driver

The L9945TR integrates eight independent MOSFET driver channels that can be configured according to different automotive load requirements.

Supported configurations:

• High-side MOSFET driving
• Low-side MOSFET driving
• Up to two independent H-Bridges
• Peak & Hold load control

Advantages:

• Flexible system architecture
• Supports multiple actuator types
• Reduces external driver complexity
• Enables platform-based automotive designs

Typical applications:

• Motor control modules
• Solenoid drivers
• Relay control systems
• Automotive actuators

2. Supports 12V and 24V Automotive Systems

The device is designed for both passenger vehicle and commercial vehicle electrical architectures.

Advantages:

• Compatible with common automotive battery systems
• Suitable for cars, trucks, and industrial vehicles
• Supports wide voltage fluctuations
• Improves application flexibility

Typical applications:

• Engine control systems
• Body electronics
• Vehicle motion systems
• Commercial vehicle control units

3. Advanced Peak & Hold Control Capability

The L9945TR supports peak & hold current control strategies for loads requiring high initial current followed by reduced holding current.

Advantages:

• Improves actuator efficiency
• Reduces thermal stress
• Optimizes power consumption
• Enhances precision control

Typical applications:

• Fuel injectors
• Solenoid valves
• Electromechanical actuators

4. Integrated Diagnostic Functions

The device provides comprehensive monitoring through dedicated SPI registers.

Diagnostic features:

• Short-to-battery detection
• Short-to-ground detection
• Open-load detection
• Output status monitoring

Advantages:

• Improves system reliability
• Enables predictive maintenance
• Simplifies fault diagnosis
• Supports automotive safety requirements

5. Programmable Gate Control for EMI Optimization

The L9945TR provides programmable MOSFET gate charge and discharge currents to control switching behavior.

Advantages:

• Reduced electromagnetic interference
• Improved EMC performance
• Optimized switching efficiency
• Better compatibility with automotive environments

6. Flexible Overcurrent Protection

The device supports advanced overcurrent monitoring through external MOSFET voltage sensing and shunt resistor measurement.

Advantages:

• Protects external power devices
• Enables accurate current monitoring
• Provides fast shutdown response
• Improves system safety

7. Automotive Safety Features

The L9945TR includes multiple safety mechanisms designed for automotive applications.

Safety features:

• Redundant external disable inputs
• Built-in self-test (BIST)
• Hardware self-check
• Communication watchdog
• Output monitoring through SPI

Advantages:

• Supports safety-critical designs
• Improves fault handling
• Enhances system reliability

Applications

Automotive Actuator Control

• Fuel injector control
• Solenoid valve drivers
• Transmission actuators
• Mechanical actuator systems

Motor Control Systems

• DC motor control
• Braking systems
• Pump control
• Fan and actuator modules

Body Electronics

• Door modules
• Seat adjustment systems
• Window control systems
• Comfort electronics

Commercial Vehicle Systems

• Truck control modules
• Bus electronics
• Heavy equipment control systems

Safety-Critical Automotive Systems

• Engine management
• Powertrain control
• Vehicle control units
• Intelligent actuator systems