2

D

DS(on)Source

DS(on)Sink

P

I

R

R

Controller

IN2

IN1

nFAULT

GND

ISEN

OUT1

VM

OUT2

0.2

Ÿ

47 µF

0.1 µF

DRV8872

+

±

6.5 to 45 V

Power Supply

PPAD

3.3 V

BDC

PU

11

DRV8872

www.ti.com

SLVSCZ0B – AUGUST 2015 – REVISED JANUARY 2016

Product Folder Links: DRV8872

Submit Documentation Feedback

Copyright © 2015–2016, Texas Instruments Incorporated

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The DRV8872 is typically used to drive one brushed DC motor.

8.2 Typical Application

Figure 7. Typical Connections

8.2.1 Design Requirements

Table 3 lists the design parameters.

Table 3. Design Parameters

DESIGN PARAMETER

REFERENCE

EXAMPLE VALUE

Motor voltage

24 V

Motor RMS current

0.8 A

Motor startup current

2 A

Motor current trip point

2.2 A

Sense resistance

0.16

Ω

PWM frequency

5 kHz

8.2.2 Detailed Design Procedure

8.2.2.1 Motor Voltage

The motor voltage to use will depend on the ratings of the motor selected and the desired RPM. A higher voltage

spins a brushed DC motor faster with the same PWM duty cycle applied to the power FETs. A higher voltage

also increases the rate of current change through the inductive motor windings.

8.2.2.2 Drive Current

The current path is through the high-side sourcing DMOS power driver, motor winding, and low-side sinking

DMOS power driver. Power dissipation losses in one source and sink DMOS power driver are shown in the

following equation.

(2)