LMD18245T/NOPB | Texas Instruments

DMOS Full-Bridge Motor Driver, LMD18245T/NOPB, Texas Instruments

The LMD18245T/NOPB full-bridge power amplifier incorporates all the circuit blocks required to drive and control current in a brushed type DC motor or one phase of a bipolar stepper motor. The multi-technology process used to build the device combines bipolar and CMOS control and protection circuitry with DMOS power switches on the same monolithic structure. The LMD18245T/NOPB controls the motor current via a fixed off-time chopper technique. An all-DMOS H-bridge power stage delivers continuous output current up to 3A (6A peak) at supply voltages up to 55V.

The DMOS power switches feature low RDS(ON) for high efficiency, and a diode intrinsic to the DMOS body structure eliminates the discrete diodes typically required to clamp a bipolar power stage. An innovative current sensing method eliminates the power loss associated with a sense resistor in series with the motor. A four-bit digital-to-analog converter (DAC) provides a digital path for controlling the motor current, and, by extension, simplifies implementation of full, half, and microstep stepper motor drives. For higher resolution applications, an external DAC can be used.

Features

• Internal Clamp Diodes
• Low-loss Current Sensing Method
• TTL and CMOS Compatible Inputs
• Overcurrent Protection
• No Shoot-Through Currents

Applications

• Full, Half and Microstep Stepper Motor Drives
• Stepper Motor and Brushed DC Motor Servo Drives
• Automated Factory, Medical and Office Equipment