3 Replies Latest reply on Jan 13, 2017 1:19 AM by RoBO_1287886

    Reference Voltage

      I am using 4 opamp for the design of filter and ADC


      I want an reference voltage in PSoC to drive the external circuit and as well as ADC.


      What are the possible ways to do it?


      Can do it using MUX or PGA or any other way?




      Umama Shireen

        • 1. Re: Reference Voltage

          Hello Umama Shireen,


          Do you want a  pin (analog out of PSoC) with a specific voltage?


          You can directly connect your analog pin to :


           - the internal Vref of PSoC (1.024V) 


           - the VDAC output, in this case you can set "any" value.









          • 2. Re: Reference Voltage

            correct me if I am wrong but will 


            connecting the reference voltage to a analog pin directly be able to give out enough current?


            Also VDAC will have its own errors 


            we want to use a circuit which can give a stable reference voltage without opamp buffer as we are going to use all the 4 available opamps of PSoC 5 LP

            • 3. Re: Reference Voltage

              I note your goal : save the 4 Opamp.


              Do you want use the PSoC also to generate a voltage reference?


              May be be you need to add external Opamp in this case


              all these parameters depends of your design : could you share a part of your design? It could be easier for us to help you.




              You have some notes into the Cypress document about the Vref option for ADC, it depends also of the Clock frequency for your ADC.