Has anybody played with a MAX232 at the wrong voltage?
It’s designed to use 5V supply and 5V TTL levels and generates +/-12V for RS232. I’ve used many over the years but all at 5V. Well 5V is very 20th century, everything is 3.3V or 1.8V now. You are meant to use a MAX3232 for 3.3V but I don’t have one to hand.
Has anyone abused one and driven it at 3.3V? I have one here running from 3.3V levels and it’s generating about +/- 8V. It’s wired to a real PC serial port and rattling away 115k2 baud perfectly. It’s driving about 50cm of ribbon cable then a 1m 9pin D genuine host 1980s vintage serial cable. Waveforms look nice and clean and everything in the garden is rosy.
It works but if anyone has any real experience of abusing them please speak up.