New Industry Products

H-Bridge Motor Driver with Integrated Current Sense and Regulation

January 20, 2020 by Paul Shepard

The DRV8874 from Texas Instruments is an integrated motor driver with N-channel H-bridge, charge pump, current sensing and proportional output, current regulation, and protection circuitry. The charge pump improves efficiency by supporting N-channel MOSFET half bridges and 100% duty cycle driving. The family of devices come in pin-to-pin RDS(on) variants to support different loads with minimal design changes.

Applications are expected to include: Brushed dc motors; Major and small home appliances; Vacuum, humanoid, and toy robotics; Printers and scanners; Smart meters; ATMs, currency counters, and EPOS; and Servo motors and actuators.

An internal current mirror architecture on the IPROPI pin implements current sensing and regulation. This eliminates the need for a large power shunt resistor, saving board area and reducing system cost. The IPROPI current-sense output allows a microcontroller to detect motor stall or changes in load conditions.

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DRV8874 block diagram (click on image to enlarge)

Using the external voltage reference pin, VREF, these devices can regulate the motor current during start-up and high-load events without interaction from a microcontroller.

A low-power sleep mode achieves ultra-low quiescent current draw by shutting down most of the internal circuitry. Internal protection features include supply undervoltage lockout, charge pump undervoltage, output overcurrent, and device overtemperature. Fault conditions are indicated on nFAULT.

Summary of Features

  • N-channel H-bridge motor driver
    • Drives one bidirectional brushed dc motor
    • Two unidirectional brushed dc motors
    • Other resistive and inductive loads
  • 5-V to 37-V operating supply voltage range
  • Pin to pin RDS(on) variants
    • DRV8874: 200-mΩ (High-Side + Low-Side)
    • DRV8876: 700-mΩ (High-Side + Low-Side)
  • High output current capability
    • DRV8874: 6-A Peak
    • DRV8876: 3.5-A Peak
  • Integrated current sensing and regulation
  • Proportional current output (IPROPI)
  • Selectable current regulation (IMODE)
    • Cycle-by-cycle or fixed off time
  • Selectable input control modes (PMODE)
    • PH/EN and PWM H-bridge control modes
    • Independent half-bridge control mode
  • Supports 1.8-V, 3.3-V, and 5-V logic inputs
  • Ultra low-power sleep mode
    • <1-µA @ VVM = 24-V, TJ = 25°C
  • Spread spectrum clocking for low electromagnetic interference (EMI)
  • Integrated protection features
    • Undervoltage lockout (UVLO)
    • Charge pump undervoltage (CPUV)
    • Overcurrent protection (OCP)
    • Automatic retry or outputs latched off (IMODE)
    • Thermal shutdown (TSD)
    • Automatic fault recovery
    • Fault indicator pin (nFAULT)