offset sine wave to square wave

[squirrel_41]

Hi guys I have a need to convert a sine wave of 2vpp with a 1.25v postive offset to square wave the sine wave is of low frequency < 40khz
I have multisim and can simulate the circuit I am trying with a op-amp but as soon as I set the sine wave to have a positive offset I lose the square wave.
any help would be much appreciated.

 

[thylacine1975]

If you simply capacitively couple (i.e. insert a series cap) your sine wave to whatever you're using (op-amp?) to "square it up" with, you should be fine - the capacitor will block the DC component, passing only your 40 kHz sine wave. Without knowing your circuit topology I can't recommend a value, so just choose C > 1/(2*pi*Rin*40E3) where Rin is the input impedance of your squarer-upper...

 

[squirrel_41]

If you simply capacitively couple (i.e. insert a series cap) your sine wave to whatever you're using (op-amp?) to "square it up" with, you should be fine - the capacitor will block the DC component, passing only your 40 kHz sine wave. Without knowing your circuit topology I can't recommend a value, so just choose C > 1/(2*pi*Rin*40E3) where Rin is the input impedance of your squarer-upper...

Hi thanks for that I have done very little work with op-amps Im useing multisim Ver 11 is it possable for you to send me a vi

 

[thylacine1975]

Sorry, but I don't use multisim - I'll have to hand the baton to someone else...

 

[squirrel_41]

It okay thank you very much I now have it working
Regards