CSD97394Q4M: Substitue part of CSD97394Q4M or restocking plan? Also the bootstrap external component value suggestion

schematic capture for reference

If the current stock shortage can be resolved in the upcoming 2 months, and we can continue to use this part, I'm thinking to add the bootstrap resistor to slow down the Vsw turn on/off speed is why I'm asking these questions.

Hi,

Please check my comments as below:

1. Is there a min-max value on the bootstrap capacitor? In the current design, this bootstrap capacitor is using a 4.7uF which I do not know the history. I am reviewing the design and want to check this by testing. But I'd also like to understand from the IC designer's point of view on the capacitor value instalment.

We usually recommend 0.1uf for BootC, but customer can decide based on their system. Larger BootC can hold HS FET ON for longer time, just need to make sure the BootC can be fully charged during startup before PWM switching operations.

2. Does the optional bootstrap resistor have a power rating requirement for the resistance value to be 1R ~ 4.7R? 

We usually use 1/16W ~1/10W together with 0.1uf BootC.  The power dissipation on this resistor is mainly in pulse format, and it's very low during steady state operation. The initial charge current might be high but only one pulse, unless frequently ON/OFF operation is expected and/or BootC is large then you may consider higher power rated.

Is there any plan on restocking this part soon or is there any similar spec & function part I can refer to?

I will check with Marketing team to answer your question.