High-Current Half-Bridge Motor Driver Evaluation with the Infineon BTN8982TA

The demand for robust and efficient motor control spans numerous applications, from automotive systems like electronic power steering and throttle control to industrial automation and high-power robotics. Central to these systems is the motor driver IC, which acts as the critical interface between a low-power microcontroller and a high-current, inductive load. This evaluation focuses on the Infineon BTN8982TA, a high-current half-bridge driver from the NovalithIC™ family, renowned for its integrated protective features and exceptional power handling capabilities.

The BTN8982TA is not a standalone full-bridge solution but rather a single half-bridge channel. It integrates a high-side P-channel MOSFET and a low-side N-channel MOSFET on a single chip, capable of delivering a continuous output current of up to 8 A (14 A peak) and operating voltages up to 28 V. Its most significant advantage lies in its high level of integration. The device combines the power MOSFETs, a charge pump for the high-side driver, and comprehensive protection circuitry into one compact, surface-mountable package (TO-263-7). This design drastically reduces the external component count, simplifies board layout, and saves valuable PCB space.

A key aspect of this evaluation is assessing the driver's diagnostic and protection capabilities, which are crucial for system reliability. The BTN8982TA provides a detailed diagnosis pin that offers feedback on several critical fault conditions:

Overcurrent Protection (IS): The current flowing through the low-side switch is mirrored on the IS pin, allowing for real-time current monitoring and facilitating advanced load diagnostics without the need for a bulky shunt resistor.

Overtemperature Shutdown: An internal temperature sensor shuts down the driver if the junction temperature exceeds a safe threshold, preventing thermal runaway.

Undervoltage Lockout (UVLO): This feature ensures the logic and driver sections operate only within a safe voltage range, preventing malfunction during power-up or brown-out conditions.

Short-Circuit Protection: The device is inherently protected against short circuits to ground, battery, and across the load.

During testing, the BTN8982TA was configured in a typical half-bridge setup to drive a DC motor. The evaluation board, featuring two BTN8982TA ICs to form a complete H-bridge, was controlled by a PWM signal from a microcontroller. Performance was characterized by measuring switching efficiency and thermal management under various load conditions. Even at high currents, the device maintained low power dissipation, thanks to its low typical on-state resistance (RDS(on)) of 16 mΩ (high-side) and 8 mΩ (low-side). The excellent thermal connection of the exposed die pad to the PCB heatsink allowed the driver to sustain high output power with minimal temperature rise, confirming its suitability for demanding environments.

ICGOOODFIND: The Infineon BTN8982TA proves to be an exceptionally robust and intelligent solution for high-current DC motor driving. Its seamless integration of power, drive, and protection simplifies design, accelerates time-to-market, and enhances the overall durability of the end application. For engineers designing systems where reliability, compact size, and diagnostic feedback are paramount, the BTN8982TA represents a top-tier component choice.

Keywords: Half-Bridge Driver, Motor Control, BTN8982TA, Overcurrent Protection, Thermal Management