Low ESR/ESL capacitors must be connected close to the device between GVDD and GND and between BSTx and SHx pins to support high peak currents drawn from GVDD and BSTx pins during the turn-on of the external MOSFETs.
To prevent large voltage transients at the drain of the top MOSFET, a low ESR electrolytic capacitor and a good quality ceramic capacitor must be connected between the high side MOSFET drain and ground.
To avoid large negative transients on the switch
node (SHx) pin, the parasitic inductances between
the source of the high-side MOSFET and the source
of the low-side MOSFET must be minimized.
To avoid unexpected transients, the parasitic
inductance of the GHx, SHx, and GLx connections
must be minimized. Minimize the trace length and
number of vias wherever possible. Minimum 10mil
and typical 15mil trace width is recommended.
Place the gate driver as close to the MOSFETs as possible. Confine the high peak currents that charge and discharge the MOSFET gates to a minimal physical area by reducing trace length. This confinement decreases the loop inductance and minimize noise issues on the gate terminals of the MOSFETs.
Refer to sections General Routing Techniques and MOSFET Placement and Power Stage Routing in Application Report