DRV8839_16 Datasheet, PDF (16/25 Pages) Texas Instruments – Low-Voltage Dual H-Bridge Driver IC

DRV8839
SLVSBN4B – JANUARY 2013 – REVISED DECEMBER 2015
www.ti.com
Thermal Considerations (continued)
For this example, V_VM = 1.8 V, V_VCC = 1.8 V, the ambient temperature is 35°C, and the junction temperature
reaches 65°C. At 65°C, the sum of R_DS(ON) is about 1 Ω. With an example motor current of 0.8 A, the dissipated
power in the form of heat will be 0.8 A² × 1 Ω = 0.64 W.
The temperature that the DRV8839 reaches will depend on the thermal resistance to the air and PCB. It is
important to solder the device PowerPAD to the PCB ground plane, with vias to the top and bottom board layers,
in order dissipate heat into the PCB and reduce the device temperature. In the example used here, the DRV8839
had an effective thermal resistance R_θJA of 47°C/W, and as seen in Equation 2:
T_J = T_A + (P_D × R_θJA) = 35°C + (0.64 W × 47°C/W) = 65°C
(2)
16
Submit Documentation Feedback
Product Folder Links: DRV8839
Copyright © 2013–2015, Texas Instruments Incorporated