User Programmable Standards Converter

[ppppenguin]

In my professional designs I've been in trouble too often for not using a bigger device. Sometimes it was because I was already using the biggest device in a family. Sometimes it was fear of specifying a more expensive device or moving to a more advanced and more expensive family. Sometimes it was because the client wanted new features in an existing design and I had to squeeze them in. Trying to squeeze a design into a crowded device is no fun at all. I've done it too often. It will usually fit, but the timing requirements go bad very easily.

As for power estimation, there are software tools for doing that but I don't really trust them. It can be worth putting very low value resistors in series with each power rail in order to monitor current. They need to be fitted in an approximation to a 4 terminal resistor to get reliable readings. Unless you're under severe cost and/or space constraints, always overdesign the power supplies. Saves a lot of trouble later.