Other Parts Discussed in Thread: ISO5451, TIDA-00638, TIDA-00446, , UCC21530-Q1, SN6505A
I am referring to the suggested circuit for the ISO5851 gate driver proposed in reference design TIDA-00446 and the very similar circuit proposed for the gate driver ISO5451 in reference design TIDA-00638.
Both designs place an RC filter in series with the power supply to the low voltage side of the driver. I have always made use of low impedance ground and power planes when supplying ICs so the notion of deliberately placing a relatively large resistance into the power supply path seems strange.
I expect this would serve the dual purpose of preventing noise from entering the gate driver from the power supply while also preventing noise from the gate driver from propogating back into the rest of the system. The application note simply says "An RC filter filters the 3.3V rail". I am in the midst of a design using the UCC21530-Q1 and I am considering whether to include a similar RC circuit. I would prefer to use a 5V power supply and I am concerned about blindly copying the component values for a different supply voltage.
Are you able to shed any light on the inclusion of this circuit and how the values are selected?