P

2

1

2

3

1

2

3

DriveCurrent

Slowdecaywithsynchronousrectification (brake)

Fastdecaywithsynchronousrectification (reverse)

VBB

DRV8800

DRV8801

SLVS855D – JULY 2008 – REVISED APRIL 2010

www.ti.com

APPLICATION INFORMATION

Power Dissipation

First-order approximation of power dissipation in the DRV8800/DRV8801 can be calculated by examining the

power dissipation in the full-bridge during each of the operation modes. DRV8800/DRV8801 utilize synchronous

power dissipation in the full-bridge. In order to prevent shoot through (high-side and low-side drivers on the same

side are ON at the same time), DRV8800/DRV8801 implement a 500-ns typical crossover delay time. During this

period, the body diode in the decay current path conducts the current until the DMOS driver turns on. High

current and high ambient temperature applications should take this into consideration. In addition, motor

parameters and switching losses can add power dissipation that could affect critical applications.

Drive Current

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

driver. Power dissipation I2R loses in one source and one sink DMOS driver, as shown in Equation 1.

(1)

DRV8800

14

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