Brushed-motor DC gate driver with adjustable current drive

July 01, 2015 // By Graham Prophet
Enabling scalable designs, this integrated, high-current gate driver with on-chip protection reduces board space by 40%.

Texas Instruments has introduced an integrated gate driver that offers adjustable gate drive settings with the flexibility to drive a wide range of external FETs, supporting multiple motors, speeds or varying loads. The DRV8701 enables designers to scale their platforms using a single gate driver across various brushed DC motor models in equipment such as white goods, household appliances, robotics, home automation, power tools, and industrial pumps and valves.

With its adjustable gate drive, advanced protection features and other integrated components, the DRV8701 brushed DC gate driver allows designers to replace up to 45 discrete components with a single device to build smaller and more robust designs.

The DRV8701 gives designers the flexibility to choose their external FETs and scale the gate-drive current to adjust the FET slew rate, optimise system EMI performance, eliminate the need for external resistors/capacitors and provide additional system protection. The integration of two low-dropout regulators (LDOs), a current-sense amplifier and full protection features reduces system board footprint by 40% compared to competitive and discrete solutions.

On-chip protection includes under-voltage lockout, overcurrent, shoot-through and thermal shutdown protection, as well as more advanced features such as charge pump under-voltage, gate-drive faults and individual FET VDS monitoring to protect external FETs. It supports a 5.9-V to 45-V motor-supply voltage for standard 2-V and 24-V supplies.

Engineers can test the gate driver in their system with the DRV8701EVM evaluation module, which also incorporates the MSP430G2553 ultra-low power microcontroller and CSD18532Q5B NexFET power MOSFET. The EVM ($49) supports up to 15A in a compact form factor that is about the size of a business card.

In a 4 x 4-mm quad flat no-lead (QFN) PowerPAD package, a thermally enhanced standard-size package designed to eliminate the need for bulky heat sinks and slugs, pricing starts at $0.92 (1000).

Texas Instruments;