I see some time from work looming
I have my pcb base layout started many months ago. So here is what it/they will be...
A 1”x1” (25.4x25.4mm) 2 layer pcb with 0.050” (1.27mm) pitch pads around the edge in a 20x20 arrangement and will take the 1.27mm pitch pin headers or sockets. The pcb will have...
* P2X8C4M64P (did I get the pn correct? and obviously included)
* 20MHz Xtal
* Bypass caps
* Transistor reset circuit and link to enable/ bypass it, plus reset pin pull-up.
Yes, that’s it. No regulator, no Flash. It’s designed to plug into a base board or whatever.
The second board will be similar to the above (1”x~1.5”) - will be longer instead of the top row of pins, and it will have a microSD socket and regulators. I will be using LDOs (not switching regulators). There will be header pins for a cheapie CP2102 USB-Serial ~$1.25 which will also provide 5V.
I will be doing an add-on board for VGA and Keyboard (PS2 or USB) connections.
It’s MHO that for many designs, power requirements will well under 500 mA and the cost of switchers is not required. For that reason, massive heat sinking is not required either.