LM5045: LM5045SQX/NOPB Can the cooling pad under the LM5045SQX/NOPB WQNF package be connected to AGND and PGND

Hi,

The LM5045 needs a separate AGND net and a PGND net to keep the return currents for the high power pins separate from the signal levels pin responsible for the correct control of the PWM duty cycle.

All signal level pins and control loop pin/circuits need to connect through the separate AGND plane for the controller. The gate drives and Vcc capacitor need to use the PGND plane for the IC to return the gates currents separately from the AGND plane.

The AGND net and a PGND net should be connected to a star point outside of thermal pad. A separate via can be used to star point the PGND for the controller to the power circuit ground.

Thermal Pad: Connect Thermal Pad to AGND only, connect AGND Net to PGND Net at single point only outside to thermal pad. The negative terminal of Vcc capacitor can be used as star point.