High-Current Half-Bridge Motor Drive with the Infineon BTN7930B PROFET™

In the world of motor control, efficiently driving high-current DC motors with precision and reliability is a fundamental challenge. The half-bridge configuration is a cornerstone topology for such applications, enabling bidirectional control in DC motors or acting as a fundamental building block for more complex three-phase inverters. The Infineon BTN7930B PROFET™ (Protected High-Side FET) is a highly integrated smart power switch engineered specifically to meet these demanding requirements, offering a robust and simplified solution for high-current motor drive systems.

The Half-Bridge: A Core Motor Drive Topology

A half-bridge circuit essentially consists of two switches, typically high-side and low-side, connected in series between the supply voltage and ground. The load, such as a motor terminal, is connected between the two switches. By controlling the switching states (ON/OFF) of these two FETs, the output can be connected to the supply voltage (high), ground (low), or set to a high-impedance state. Two such half-bridges form a full H-bridge, which is the standard architecture for bidirectional control of a single DC motor, allowing for forward, reverse, braking, and coasting operations.

Introducing the BTN7930B PROFET™: An Integrated Powerhouse

The BTN7930B is far more than a simple MOSFET. It is a fully integrated high-current half-bridge driver housed in a single package. Each chip contains a high-side P-channel MOSFET and a low-side N-channel MOSFET, pre-configured for optimal performance. This integration eliminates the need for complex discrete MOSFET selection and matching, saving significant board space and design time.

A key feature of the PROFET™ family is its comprehensive suite of built-in protection features. These include:

Overcurrent Protection (IS): Safely limits the output current during a short circuit or motor stall.

Overtemperature Protection (TSD): Shuts down the device if the junction temperature exceeds a safe threshold, preventing thermal runaway.

Undervoltage Lockout (UVLO): Disables the switches if the supply voltage is too low, ensuring correct operation and preventing excessive current draw.

Overvoltage Clamp (VS): Protects the device from voltage transients on the supply line.

These features make the system inherently more robust and reliable, reducing the burden on the microcontroller and external circuitry.

Driving Motors with High Precision and Current

The BTN7930B is capable of handling continuous currents up to 30 A and peak currents even higher, making it suitable for a wide range of applications from automotive actuators to industrial automation and robotics. Its low typical on-state resistance (RDS(on)) of only 16 mΩ (high-side + low-side) ensures high efficiency by minimizing conductive losses, which in turn reduces heat generation.

Control is achieved through two dedicated input pins (IN and INH) for each half-bridge, which are compatible with standard 3.3 V or 5 V microcontroller logic levels. The diagnostic feedback pin (IS) provides a current-sense signal proportional to the load current, enabling the microcontroller to monitor motor performance and detect fault conditions like stall or block without the need for an external shunt resistor.

ICGOOODFIND

The Infineon BTN7930B PROFET™ represents an exceptional integration of power, control, and protection. It dramatically simplifies the design of high-current motor drives by consolidating multiple discrete components into a single, intelligent package. For engineers developing systems for automotive, industrial, or robotics applications, the BTN7930B offers a compelling combination of performance, reliability, and design efficiency, making it an outstanding choice for next-generation motor control solutions.

Keywords:

1. Half-Bridge Motor Drive

2. High-Current Capability

3. Integrated Protection Features

4. BTN7930B PROFET™

5. Efficient Power Switching