Level shifter for DC voltage

[sohailto]

Dear all,
I want to design a circuit which shifts the 0-3.3V signal from a PWM (filtered) output to -5V to +5V range. Any idea will be highly appreciated.
Thanks

 

[viperpaki007]

Normally DC-DC converters are normally used for this purpose. What is your intended application. If its a discrete design then u can use LM317 and LM337 ICs

 

[picgak]

Hi sohailto,
from your i understand that you want to shift the level of output pulses for that you can use an opamp comparator with +5, -5 supply voltage after that you can filter
regards ani

 

[rohitkhanna]

Dear all,
I want to design a circuit which shifts the 0-3.3V signal from a PWM (filtered) output to -5V to +5V range. Any idea will be highly appreciated.
Thanks

So is your signal a PWM, or is it filtered.... in which case I assume you have filtered it sufficiently to derive the 'base' pwm variations, and now you simply have an analog output between 0 - 3.3v.

Yes?

Then what you need is a straightforward opamp gain circuit, where the gain is set to x3.0303 --> a 10v swing
Now in addition you need to apply an OFFSET voltage to the opamp inputs as well, to bring that 10v swing so that it's centered around 0v. Do remember that any offset voltage applied will ALSO have a gain, depending on what resistor ratio you use. So make sure you divide 5v by this ratio to determine what input voltage to use!!

Oh yes... you would need a powersupply of around +/-7v at least for your opamp, unless it's a R-R type

you follow ?
cheers!

 

[sohailto]

Yes Rohit, you got it. It is actually LCD bias circuit to compensat temperature variations. The offset would be 1.65V, I think. Am I right? I have, however, +/- 5V supply available.

Thanks.