Need an 8 bit ic to convert ac signal (-5v-5v)

Thread Starter


Joined Jan 22, 2019
Im working on a student project to design a pcm system. I couldn’t find an adc that works with ac signals. How can i solve this problem ?


Joined Feb 20, 2016
Do you want to measure the instantaneous voltage, peak AC voltage or just anything between +/-5V? What sample rate.
Must it be 8bit or can you use higher? What package do you require?

There are many bipolar ADCs around.
More info please.


Joined Feb 20, 2016
Why only an 8 bit ADC? You can use 10 or 12 bits and throw the other bits out. It may be easier to find a 10 or more bit ADC.
Do you want SPI, I2C or what interface? Does it matter?
What is the processor you are wanting to use?
Lots of questions.
It does make it a lot easier to help if you explain your requirements better.


Joined Jun 19, 2012
Use a simple opamp circuit-

1) Scale the signal down 50% to +- 2.5V (voltage divider)

2) Offset it positive by 2.5 V (differential amplifier and 2.5 V reference)

Result is then 0-5 V- you can feed this directly into a 5V ADC, which are very common.