# Using a voltage divider with buried zener voltage reference

My plan in the below circuit was to use a voltage divider from a Max6225 2.5Vref, to get 2V and 1V from it in order to use the full 16bit bipolar scale of the ADS1115s, but I'm getting strange resistance readings from a DMM across the resistors - can I use a voltage divider with the Vref like this?

EDIT: Apologies for the drawing - not sure how to do the buried zener vref part, so I've marked the connections instead OK.

EDIT 2: Please ignore the test resistor in the bottom picture - this was just to test if the same thing happened however I connected a resistance from Vref out back to ground, rather than a short or something on the board

• How did you measure strange R's ? The Max IC can supply 20mA Aug 30, 2018 at 22:14
• Preferably not, why would you use a precise voltage ref to spoil it with resistors? At lest you should buffer and divide with some opamp. The best is to use separate voltage refs. Aug 30, 2018 at 22:16
• @TonyEErocketscientist Without a power supply connected, I connected the DMM across the resistors. The bottom (in the picture) blue resistor is 3.09K - but came out 2.54 for example. Aug 30, 2018 at 22:25
• @MarkoBuršič For one, I was going to use it for some thermistors in a voltage divider format. I'd rather not have to use seperate vrefs - if Opamps will solve this problem I will do that then, cheers Aug 30, 2018 at 22:31
• It looks like you have two resistors in parallel connected to one in series. You can't make voltage divider this way. All three resistors should be in series. However it is impossible to tell for sure from your photo. If you want definite answer you need to post a schematics, or at least the part of it in question. Aug 30, 2018 at 22:49