DRV8850_16 Datasheet, PDF (20/30 Pages) Texas Instruments – Low-Voltage H-Bridge IC with LDO Voltage Regulator

DRV8850
SLVSCC0B – NOVEMBER 2013 – REVISED DECEMBER 2015
www.ti.com
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.
P_D = I² (R_{DS(ON)_HS} + R_{DS(ON)_LS)}
(3)
The DRV8850 has been measured to be capable of 5-A RMS current at 25°C on standard FR-4 PCBs. The
maximum RMS current varies based on PCB design and the ambient temperature.
8.2.3 Application Curves
Figure 19. I_M Start-Up after LDOEN and nSLEEP Toggle
Figure 20. I_M Start-Up Delay after LDOEN and nSLEEP
Toggle
20
Submit Documentation Feedback
Product Folder Links: DRV8850
Copyright © 2013–2015, Texas Instruments Incorporated