2.5v-5v to 0-3.3v

[Wond3rboy]

Hi i want to make a level shifter for making a 2.5v to 5v signal from my Flex sensor divider to 0-3.3v(0-2.5 would be fine). ?I know how to make a positive level shifter that increases the level but do not know how to downgrade the signal.The source impedance of the divider is about 10k.Can anyone help me out?

 

[ericgibbs]

Hi i want to make a level shifter for making a 2.5v to 5v signal from my Flex sensor divider to 0-3.3v(0-2.5 would be fine). ?I know how to make a positive level shifter that increases the level but do not know how to downgrade the signal.The source impedance of the divider is about 10k.Can anyone help me out?

hi,
One way is to use a OPA level shifter.
Which types of OPA [op amps] are available in your area.?

 

[Wond3rboy]

I am trying to configure the level shifter that i made using an lf411, i do have a ka358 but guessed that the LF411 is a much better opamp.

 

[ericgibbs]

I am trying to configure the level shifter that i made using an lf411, i do have a ka358 but guessed that the LF411 is a much better opamp.

hi,
OK, I will post a circuit later today showing a shifter using a LM358.

 

[Wond3rboy]

Thanks Eric until you do i will try to do something on my own.

 

[ericgibbs]

Thanks Eric until you do i will try to do something on my own.

hi W3,
Look at this option, the LM358 is a dual OPA.

 

[Wond3rboy]

Hi Eric, here is my circuit using the LF411.Since it can go to a max of Vcc-1.5 so i have changed the values.Didnt use the KA358 since it is specified in its datasheet that the i/p can to a max of Vcc-1.5.I will operate the LF411 using 5V.I do want to see the circuit that you come up with since you are a pro at this but just wanted to show and ask whether this will do.I think it works atleast it does in simulation.But i do want to see what approach to you make.Thanks.


PS:Just saw your ckt.

 

[ericgibbs]

Hi Eric, here is my circuit using the LF411.Since it can go to a max of Vcc-1.5 so i have changed the values.Didnt use the KA358 since it is specified in its datasheet that the i/p can to a max of Vcc-1.5.I will operate the LF411 using 5V.I do want to see the circuit that you come up with since you are a pro at this but just wanted to show and ask whether this will do.I think it works atleast it does in simulation.But i do want to see what approach to you make.Thanks.

hi,
Your circuit will not the give the output you require.

I have modified your asc file to show you problem.