CMOS level shifter

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gtmbht

Joined: 03 Feb 2006
Posts: 4

03 Feb 2006 4:00 CMOS level shifter

Hello,

I would like to shift a square wave operating between 0-1.8v to one operating between 1.8-3.6V. I tried using a conventional level shifter (domino like circuit). Unofrtunately it only shifts the upper level and not the lower , i.e., the wave output is between 0-3.6V and not 1.8-3.6V (desired). Please help me with this issue

Thanks
Gautam

montage2000

Joined: 07 Jan 2006
Posts: 39
Helped: 3

03 Feb 2006 13:56 CMOS level shifter

you can shift 0-3.6 to 1.8 -3.6

gtmbht

Joined: 03 Feb 2006
Posts: 4

03 Feb 2006 23:25 Re: CMOS level shifter

I apologize, maybe I am taking too much time to understand something trivial, but how would I shift 0-3.6 to 1.8-3.6?

thanks

gautam

IanP

Joined: 05 Oct 2004
Posts: 6491
Helped: 1542
Location: West Coast

04 Feb 2006 4:11 Re: CMOS level shifter

0-3.6V can be converted to 1.8-3.6V with a resistor and 1.8V zener diode .. see picture below ..

Regards,
IanP

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OpAmp

Joined: 19 May 2003
Posts: 61
Helped: 15

04 Feb 2006 18:52 CMOS level shifter

Hi,

You can shift a pulse waveform from 0-1.8 to 1.8-3.6 using a simple RC circuit. consider the following circuit netlist:

C in out Cvalue
R out dd Rvalue
Vdd dd 0 1.8

Cvalue and Rvalue depends on the frequency of operation.

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gtmbht

Joined: 03 Feb 2006
Posts: 4

05 Feb 2006 1:40 Re: CMOS level shifter

I tried implementing the same level shifter on 0-3.6 square wave .... with vdd=3.6 and vss=1.8 this time...and guess what?? it works!!....thanks a lot for your ideas ...really appreciate the help.

Gautam