L9904 Power MOS Bridge Driver IC – PWM Controller for Automotive DC Motor & Valve Control
The L9904 is a dedicated control circuit designed specifically for driving external N-channel power MOS transistors in an H-bridge configuration. It is an ideal solution for DC-motor and electronic valve (solenoid) control in demanding automotive environments. The device integrates a wide array of protective features and an ISO 9141 compatible interface, ensuring reliable communication and operation within vehicle networks.
Technical Specifications & Power Supply:
This controller supports a standard operating supply voltage range from 8V to 28V, making it suitable for standard 12V and 24V automotive electrical systems. Furthermore, it features robustness against overvoltage conditions up to 40V. For systems operating under low battery conditions, an implemented step-up converter allows for continued operation down to 6V. The quiescent current in standby mode is exceptionally low, measuring less than 50µA, which helps preserve battery life when the engine is off.
PWM & Motor Control Capabilities:
The device supports Pulse Width Modulation (PWM) operation at frequencies up to 30kHz, offering flexibility for various motor speed and torque control strategies. It features a programmable cross-conduction protection time, which is essential for preventing shoot-through currents in the H-bridge that could damage the external MOSFETs. The built-in charge pump is specifically designed to drive a power MOS for reverse battery protection, eliminating the need for a bulky protection diode.
Protection & Diagnostic Features:
The L9904 is equipped with comprehensive real-time diagnostic functions to ensure system integrity. It includes overvoltage shutdown, undervoltage shutdown, short-circuit protection, and thermal protection mechanisms. The open-drain diagnostic output provides a low signal when an error occurs, allowing the main microcontroller to monitor the health of the driver stage continuously.
Conclusion & Application:
By utilizing the L9904, automotive system designers can simplify the design of motor control units (MCUs) and electronic valve drivers. Its high level of integration reduces external component count while improving system reliability and safety, making it a robust choice for modern vehicle electronics.