[sdiy] Voltage dividers - best practice

[Antti Huovilainen]

On Sat, 2 Aug 2008, Justin Owen wrote:

> When I come to laying out the PCB - would it be best practice to have 
> individual voltage dividers providing the reference voltage at the 
> points closest to where they're need (i.e. multiple dividers like I have 
> now)? Or would it be better to have one reference point and have 
> everything drawing from that? Or does it make no difference?

You'd be best off using a dedicated 3-terminal voltage reference and an 
opamp to provide one common Vref and then have all voltage dividers 
connected to that. LM385, TLC431 or other el cheapo reference  will do 
fine, the goal is to make the Vref independent of exact V+ value and noise 
coupling through power supply.

Antti

"No boom today. Boom tomorrow. There's always a boom tomorrow"
   -- Lt. Cmdr. Ivanova