I have been studying some datasheets for gate drivers and some feature RC filters in line with the power supply to the low voltage side. I was quite surprised by this as it seemed to go against everything I thought I knew about providing power to an IC. I have always used low impedance power and ground planes and observed good layout practices to reduce inductance. Putting such a large resistor in series with a power supply would appear to go against the conventional wisom of providing an ideal, low impedance supply to a device.
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 datasheet simply says "An RC filter filters the 3.3V rail". I am concerned that if I select a different IC where the values are not specified that getting them wrong could cause problems. I would also prefer to use a 5V rail.
Can anyone clarify the role of this circuit anymore and how it should be designed? Could a ferrite bead serve a similar purpose?
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 datasheet simply says "An RC filter filters the 3.3V rail". I am concerned that if I select a different IC where the values are not specified that getting them wrong could cause problems. I would also prefer to use a 5V rail.
Can anyone clarify the role of this circuit anymore and how it should be designed? Could a ferrite bead serve a similar purpose?