Unipolar to Bi polar conversion

[muthuselvam]

unipolar to bipolar converter

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.

 

[PoojanWagh]

unipolar to bipolar conversion

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)

MP1 Vo2 Vi1 VDD3 VDD3
MP2 Vo1 Vi2 VDD3 VDD3
MN1 Vo1 Vo2 VSS8 VSS8
MN2 Vo2 Vo1 VSS8 VSS8

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.

--
https://www.circuitdesign.info

 

[FvM]

convert unipolar to bipolar

But i have to parallelly use 5 signals.I could not able to synchronize all these 5 signals due to common refernce voltage.

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.

 

[DrBob13]

level shifter bipolar

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.

**broken link removed**

Cheers
Bob.