1 Features

? Dual H-Bridge Motor Driver

– Single/Dual Brushed DC

– Stepper

– Solenoids

? 4 to 18V Operating Supply Voltage Range

? Low ON-resistance: HS + LS = 900mΩ (Typical,

25°C)

? High Output Current per H-Bridge

– 2A Maximum Driver Current at 12V and TA =

25°C

– Parallel Mode Available Capable of 4A

Maximum Driver Current at 12V and TA = 25°C

? Device versions:

– DRV8421A (4-wire input): Independent Half

Bridge Control

– DRV8421B (2-wire input): Sleep Mode, Fault

detect

? Similar LV Stepper Drivers:

– DRV8410: 1.65 to 11V (800mΩ RDS(ON))

– DRV8411: 1.65 to 11V (400mΩ RDS(ON))

– DRV8411A: 1.65 to 11V (400mΩ RDS(ON))

? PWM Control Interface

? Low-Current 3μA Sleep Mode (2-wire input version

only)

? Thermally-Enhanced Surface Mount Package

? Protection Features

– VM Undervoltage Lockout (UVLO)

– Overcurrent Protection (OCP)

– Thermal Shutdown (TSD)

– Fault Condition Indication Pin (nFAULT) (2-wire

input version only)

2 Applications

? Household Appliances

– Printers/Scanners

– Refrigerators

– Vacuum Cleaners

– Clothes Dryer

? General Brushed and Stepper Motors

3 Description

The DRV8421 provides a dual H-bridge motor

driver for home appliances and other mechatronic

applications. The device can be used to drive one

or two DC motors, a bipolar stepper motor, or other

loads. A simple PWM interface allows easy interfacing

to controller circuits.

The output block of each H-bridge driver consists

of N-channel power MOSFETs configured as full Hbridges

to drive the motor windings. The DRV8421

is capable of driving a maximum current of 2A from

each output or 4A in parallel mode (with proper heat

sinking, at 12V and TA = 25°C).

The device contains two versions having a 4-wire

input (DRV8421A) or a 2-wire input (DRV8421B). The

2-wire input version (DRV8421B) contains features

like enable and fault detection, while the 4-wire input

version (DRV8421A) can drive four half bridges based

on signals to four input terminals. A low-power sleep

mode is also provided for the 2-wire input version.

It shuts down internal circuitry to achieve very-low

quiescent current draw. This sleep mode can be set

by pulling the enable pin low.

Internal protection functions are provided for UVLO,

OCP, short-circuit protection, and overtemperature.

Fault conditions are indicated by a nFAULT pin in the

DRV8421B, the 2-wire input device.