Interfacing Uni-polar ADC to Bi-polar Signal

[hynix]

Hi,
Can any body out there tell me or any schematic how can I interface the Bi-polar signal (+/-1.5v ) signal to my 3.3 v adc working in unidirectional conversion(0-3v) Signal.

 

[Circuit_seller]

Hi

You can use an op-amp to move your input signal around 1.5v.
Or use a level shifting circuit to do it.

Regards

 

[artem]

If DC part is necessary , you can use 3 serially connected diodes powered by current source (to make linear shift) connected to amplifier output .

If just AC will be measured , simple RC with level shift will be enough .

 

[abasir]

The simplest is two identical resistors (values depending on your ADC input requirement) as follows:

signal input ----/\/\/-----+----/\/\/-----VDD (3.3V)
connect at + to ADC input.

With above, yr input range is -3.3V to +3.3V.

If you need the smaller range -1.5V to +1.5V, you need some other level shifting circuit

 

[nebisman]

Use a vltaje divisor and a follower with Opamp. Connect your signal to the virtual ground generated in the output of the opamp

 

[hynix]

Hi,
Intresting !!!

My signal varies +/-1.7v max from the 0v Reference
I wanted to shift the signal to a fixed level of 1.7v from the 0v reference
so that the signal should oscillate at the dc shift of 1.7v making +/- 3.4v from 0v reference
and then I can give to a unipolar adc (0 to 3.4v full scaled) for the conversion.

please sugest me some more idea or shematic.