Voltage Drop on V Ref circuit

[RickWI]

On a 0-5 volt ref circuit what is the acceptable voltage drop. I know for instance 2/10 drop is acceptable for say a 12V circuit but we are trying to find out what it would be for a 0-5, or 0-7 volt circuit.

 

[bobc455]

Acceptable in what way? Most 12V power drops are "power" circuits, most 5V circuits are "control circuits with very low amperages.

Is this for a TPS?

-Bob Cunningham

 

[RickWI]

From the standpoint of what is acceptable. A TPS is an example. If the control circuit is supposed to be 5v then what is acceptable for the voltage drop on that circuit? Simple as that really. I know the control circuit is very low load. Somewhere there has to be a tolerance spec though for these types of circuits. It is a rhetorical question really. One that was posed to me a few days ago and I just stood there and scratched my head.

 

[Brooks]

I can give you a "worst case" rule of thumb if it would help.

Deviation in a reference source should be less than the resolution of the ADC or sensitivity of an analog sensing circuit. i.e. if you have an 8 bit ADC (256 steps) the maximum deviation should be less than 19mv.



Charles Brooks

 

[RickWI]

Thanks Charles, appreciate it.