Hi everyone, I am working on putting an analog design on the MPW-5 shuttle and while placing my design on the user_analog_project_wrapper and connecting pins, I am having this doubt as to what the structure of the pins are. I am using the

gpio_analog

,

gpio_noesd

,

io_analog

pins for my design. It would be great if someone who is aware of it can share the structure of these pins and the ESD that is present so I can design buffers and measurement circuits that can work effectively with the load resistance and capacitance exerted by the pins and ESD. Thanks!

You can read the analog user projects verilog for purpose of each pin. Regarding the structure of caravel/caravan you can also take a look at caravels verilog as it contains all components + connections. gpio components are installed by openpdks and are properly documented by skywater docs

gpio_analog

has a 150 Ohm resistance in series to provide some ESD protection.

gpio_noesd

doesnot have this resistor.

io_analog

are barewire metal pads for highspeed/high voltage applications

Try this. https://skywater-pdk.slack.com/archives/C016HUV935L/p1642649922078800

Thank you @User @User and @User.