grounds problem?

[electricity86]

Hello everyone.

I own a chip which has a voltage channel, and through this channel, it receives 2 differential voltage inputs, up to 250mV.
When supplying the chip directly (to the chip's pins) a 100mV input, it worked well.
But, when supplying the chip a 100mV through a resistive divider (but still 100mV were falling on the chip voltage inputs), the chip didnt output correct results (the measurements of the chip were wrong).

i was thinking that maybe the fact the in the first scenario the signal generator (which was the AC voltage source) ground were connected directly to the chip had something to do with the success of the measrements.

What do you think?
Thanks!

 

[Leftyretro]

Hello everyone.

I own a chip which has a voltage channel, and through this channel, it receives 2 differential voltage inputs, up to 250mV.
When supplying the chip directly (to the chip's pins) a 100mV input, it worked well.
But, when supplying the chip a 100mV through a resistive divider (but still 100mV were falling on the chip voltage inputs), the chip didnt output correct results (the measurements of the chip were wrong).

i was thinking that maybe the fact the in the first scenario the signal generator (which was the AC voltage source) ground were connected directly to the chip had something to do with the success of the measrements.

What do you think?
Thanks!

I think we would need to know what the chip is (device #) and possibly a diagram of how you are using it to be of any assistance to you.

Lefty