I would like to ask you about the ground and power supply connections for the MP1918 Gate Driver.
The datasheet states that AGND and PGND must be separated in the PCB layout to prevent noise from transferring from the PGND to the AGND, and a 0-ohm resistor should be connected between AGND and PGND.
My questions are:
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Why is it necessary to connect AGND and PGND via a 0-ohm resistor?
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Am I forced to connect this resistor between them, or can I just leave the grounds completely separated?
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Why is there a separation of these grounds inside the IC in the first place?
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If I connect the PWM inputs (which are referenced to AGND) to an Isolator chip that outputs PWM signals referenced to PGND, does this mean I cannot use an isolator at all with the MP1918?
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Regarding the VCC connection: the component has VCC1 (pin 14) which must be referenced to AGND, and VCC2 (pin 10) which is referenced to PGND. If I connect both VCC1 and VCC2 to the same 5V source, but on the board one is referenced to PGND and the other to AGND, noise will enter the 5V line and pass into the VCC1 supply. If so, what is the benefit of connecting VCC this way?