ZHCSIO5B October 2017 – January 2021 DRV8873-Q1
PRODUCTION DATA
For optimal performance, the sense resistor must have the following features:
Use Equation 10 to calculate the power dissipation (PD) of the sense resistor.
In this example, for the RMS motor current is 2.5 A, the sense resistor of 1.5 kΩ dissipates approximately 7.5 mW of power. The power quickly increases with higher current levels. Resistors typically have a rated power within some ambient temperature range, along with a derated power curve for high ambient temperatures. When a PCB is shared with other components that generate heat, the system designer should add margin. Measuring the actual sense resistor temperature in a final system is best.