I am designing a PGA2500 base preamp and have some pads and phantom to switch.
I can use optomos relay to switch the phantom power with GPO from PGA2500 to isolate from
digita noise or just use a N & P channel mosfet.
to switch in / out the pad I have found a bipolar low noise switch.
my question is , do I need to isolate the GPO from both the pad switch and the phantom switch.
I know the GPO is designed for this job but did they include any noise isolation ?
Also , if I use an optomos for phantom power switching I need 8ma @ 5v. I could'nt find the
GPO output specs regarding power. anyone know ?
I will be using a SPI isolator for MOSI MISO lines so I could just run extra traces from MC to operate pad and phantom power switch
but would rather use the GPO if its low noise?