+ve/-ve rail generator using OPAMP

[kbm10]

I am a newb in analog desing .

I have to design a circuit using an opamp which amplifies an input signal(0-5V) to upto (0-12V). I am using an opamp for the same. I have a single rail supply (0-24V). The problem is I have to split the rails first before I can use it with an opamp. Is it possible to split the rails to +ve/-ve rails(-12 to +12) using OPAMPs ?

Can anyone suggest some circuit which uses OPAMP for the same and give a brief explation ?

 

[godfreyl]

You can use a rail-splitter circuit like the one below. The two resistors make a voltage divider to get a voltage inbetween the plus and minus rails, then the opamp is used as a buffer to give a low impedance.

If the resistors were the same value you would get +-12V. However your amplifier must give output up to 12V, so the positive supply must be higher than 12V. That's why I chose +18V and -6V.

If the 0V output is connected to ground (like in the picture), then the 24V power supply must not be connected to ground, otherwise there will be a short circuit.

 

[btbass]

If you are amplifying a 0-5 DC voltage, you do not need to split the supply rails.
Just use a single supply rail to rail op amp.

 

[kbm10]

@godfreyl thnx
@btbass if I use a rail to rail opamp and the voltage and the supply is 0-5V and when the input is 0V will that not give wrong output because of the common mode voltage range of opamp? is there an opamp with 0V common mode voltage ?

@godfreyl

also, for generating the gorund(0 V) do i need another circuit ?

 

[btbass]

A input/output rail to rail op-amp should give good results.

You could just use two resistors and a cap to bias the non-inverting input feedback point.
I don't think You need a split rail.

 

[kbm10]

thnx for your reply..

But the input that I am using pulse, so using a capacitor may affect it .. or maybe should I use a very small cap ?

 

[crutschow]

A rail-to-rail op amp configured as a non-inverting amplifier will work down to zero volts input. You don't need to bias either input. The op amp just needs to be able to operate from 24V (or whatever supply voltage you have).

What is the width and repetition rate of the pulse?