Hello!
I am using an ESP32-WROOM-32 chip and I want to control an HV5622PG-G chip with it. The ESP32 uses 3.3V logic and the HV5622PG-G uses 12V logic. I want to level shift four signals which will be outputs on the ESP32 so they will only go from 3.3V to 12V. One signal is a clock signal. How should I level shift these signals?
Thank you and have a wonderful day!
Use a transistors. For example:
It should work for 3.3V input as well. You can also decrease R1 value.
I had a quick look at the datasheet and it looks like you can run the logic at 3V3, although 12V is recommended. If it were me I'd just try it and see if it did what I wanted.
Well, the datasheet says Vdd should be 10.8V or greater and logic high must be > Vdd-2.
However it also says "CMOS compatible inputs" which is rather at odds with those specs.
I read this as the output devices are nominally 12V gate drive so the supply cannot be much
less than 12V, and the input circuits are plain old-fashioned CMOS (4000 series) which have
voltage thresholds that scale with the supply.
However perhaps the datasheet is pants and the device does work from 5V logic inputs?
For level shifting BJTs are a reasonable approach, but if speed isn't an issue you could use
something like a ULN2003 and pull-up resistors - one chip replaces 4 transistors which could
be neater.