Hi I have to convert 0v to 3v square wave signal into -8v to +3v square wave signal without affecting on/off time.I have used a high speed comparator in inverting mode.But i have to parallelly use 5 signals.I could not able to synchronize all these 5 signals due to common refernce voltage.Can you please give me any suggestion? Thanks in advance.
I assume you have 0-3V signal as fully differential square waves. If not, add an inverter (on the 0 - 3V supply) to make the inverse of the square wave.
Take the 0-3V signals (Vi1 & Vi2) and put them into gates of two 11-V tolerant PMOS devices (source tied to 3 V supply) the drains of the PMOS devices are outputs (Vo2 & Vo1).
Add some 11-V tolerant NMOS devices. The drains of the NMOS devices connect to the output. The source/bulks connect to ground. The gates of the NMOS device connects to the other side's output.
Here are the connections:
(transistor drain gate source bulk)
There will be delay on the -8V to 3V outputs (relative to the 0V to 3V inputs). To keep your -8V to 3V signals synchronized with your 0 V to 3V signals, add some inverters to the 0V to 3V signals to delay them.
This is a typical cross-coupled CMOS level shifter.
Don't see what should be synchronized in a multi channel level converter. Using an inidvidual converter (e. g. a comparator) for each channel is all you have to do.
Hello,
You could probably do this with two 311 comparators, I came across this circuit when I was looking for something else and thought about your app. See page 16 of the datsheet for the possible circuit, you will need to use different supplies -8V and +3V and fiddle with the resistor values a bit but it should work.