Outputting Internal 1.024V Vref on CYBLE-014008-00

[user_1669321]

Hi,

   

Is it possible to output the internal voltage reference of the CYBLE-014008-00 to a pin? I saw this blog (http://www.cypress.com/blog/psoc-hacker-blog/connect-vref-pin-psoc4) that said it was possible on PSoC 4, but it kept referencing P1.7, which is not available on this specific device.

   

Thank you,

   

Fred

[Anonymous]

I believe you have to use an opamp between the reference and the pin.  This is working for me.

[user_1669321]

But I don't have (or don't seem to have) access to the VREF pin from the pin assignment window. There also isn't a component VREF in the Top Design schematic.

[Anonymous · Accepted solution]

Hi Fred,

By setting the SAR ADC's reference voltage to 'Internal 1.024 voltas, bypassed', you can get the 1.024V on the VREF pin.

In CYBLE-014008, pin 26 is the VREF pin. Connect a 1uF cap on this pin and you will be able to measure the VREF voltage.

For some PSoC 4 devices, the VREF pin is coupled with P1.7 and there is no dedicated VREF pin. For those devices, you need to follow the guide referenced by you. For PSoC 4 BLE devices, there is a dedicated VREF pin and you don't have to do any of those configurations.

[user_1669321]

Thank you!