SLVSEE9D April 2020 – April 2021 DRV8889-Q1
PRODUCTION DATA
The current path for a motor connected in full-bridge is through the high-side FET of one half-bridge and low-side FET of the other half-bridge. The conduction loss (PCOND) depends on the motor rms current (IRMS) and high-side (RDS(ONH)) and low-side (RDS(ONL)) on-state resistances as shown in Equation 4.
The conduction loss for the typical application shown in Section 8.2.1 is calculated in Equation 5.
This power calculation is highly dependent on the device temperature which significantly effects the high-side and low-side on-resistance of the FETs. For more accurate calculation, consider the dependency of on-resistance of FETs with device temperature.