SLVSAS7D February 2011 – March 2021 DRV8801-Q1
The power dissipation of the DRV8801-Q1 is a function of the RMS motor current and the each output’s FET resistance (RDS(ON)).
For this example, the ambient temperature is 35°C, and the junction temperature reaches 65°C. At 65°C, the sum of RDS(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 A2x 1 Ω = 0.64 W.
The temperature that the DRV8801-Q1 reaches will depend on the thermal resistance to the air and PCB. It is important to solder the device thermal pad to the PCB ground plane, with vias to the top and bottom board layers, to dissipate heat into the PCB and reduce the device temperature. In the example used here, the DRV8801-Q1 had an effective thermal resistance RθJA of 47°C/W, and: