Put a 2.2-µF ceramic capacitor on VCC pin in addition to the energy storage electrolytic capacitor. The 2.2-µF ceramic capacitor should be put as close as possible to the VCC pin.
RVCC pin should have a bypass capacitor of 4.7 µF or more. It is recommended to add a 0.1-µF ceramic capacitor in addition to the 4.7 µF. The capacitors should be put as close as possible to the RVCC pin. RVCC cap needs to be at least 5 times of boot capacitor.
Minimum recommended boot capacitor is 0.1 µF. The minimum value of the boot capacitor needs to be determined by the minimum burst frequency. The boot capacitor should be large enough to hold the bootstrap voltage during the lowest burst frequency. Please refer to the boot leakage current in the electrical table.
Use large copper pour around GND pin
The filtering capacitor on BW, ISNS, BLK should be put as close as possible to the pin
FB trace should be as short as possible
Soft-start capacitor should be put as close as possible to LL/SS pin
Use film capacitor or C0G, NP0 ceramic capacitor on VCR divider and ISNS capacitor for low distortion
It is recommended that ISNS resistor is less than 500 Ω to keep the node impedance low
Add necessary filtering capacitors on BW pin to filter out the high spikes on the bias winding waveform. It is critical to filter out the high spikes because internally the signal is peak detected and then sampled at the low side turn off edge.
Do not put any capacitor on HV pin to ground. The layout of this pin should result in low parasitic capacitance (<60 pF) from HV pin to ground.