Measuring the internal reference voltage using ADC

[Anonymous]

Hy,

   

I am trying to read the battery voltage, but the reference voltage (VDDA) is not stable at all. Therefore, the output of the ADC varies a lot. I was thinking to use another resistive divider to be able to reference everything to 1.024V, but I have a lot of PCBs and I do not want to make this modification on each. Therefore, I am wondering if there is a solution to measure the reference voltage and then, from this, calculate the real VDDA.

   

I am using a PSOC 4xx7 BLE

       

Thank you in advance

[rola_264706]

        What is the exact part numbet?. I have found the reference voltage to be stable. You can use the internal vref and bring it out for measurement or other uses.   

[Anonymous]

Please refer the below link for more information:

   

http://www.cypress.com/blog/psoc-hacker-blog/measuring-vdd-battery-volts-psoc4

   

If supply is not stable, and if this is being provided as reference, the ADC output won't be stable. So it is required to have stable power supply. For current fix, high capacitor can be connected in power supply lines which could remove fluctuations and make it stable. Let me know if this helps.

   

Thanks

   

Ramesh B