10.1.8 GND Pin
The GND pin is the bias-power and signal ground connection for the controller. The effectiveness of the filter capacitors on the signal pins depends upon the integrity of the ground return.
- Place the decoupling and filter capacitors on VDD, REF, CS, and HVG pins as close as possible to the device pins and GND pin with short traces.
- The device ground and power ground should meet at the return of the current-sense resistor (RCS). Try to ensure that high frequency/high current from the power stage does not go through the signal ground.
- The thermal pad of the QFN package should be tied to the IC GND pin with a short trace, and be connected to the signal ground plane with multiple vias which becomes a low-impedance ground return of external components to the GND pin.