3 Replies Latest reply on May 7, 2017 11:29 PM by anks

    CY8CKIT-059 / Kitprog / 3.3V Operation Questions

    karl.asha

      Although I've seen a few variations of this questions, I would like to verify some additional points prior to modifying the prototyping board. Section 4.2.3 details the options around powering the device. 

         

      When powering from an external regulated supply connected to VDD: 

         
          

      "KitProg measures the target voltage and adjusts the logic levels on the programming pins accordingly."

         
         

      Three questions from this: 

         

      1) Which pin does the KitProg sample to measure the target voltage?

         

      2) For the UART_TX, UART_RX, I2C_SDA, and I2C_SCL signals that are connected between the target and KitProg, do those logic levels also become adjusted based on the target voltage? Or, would they need to be broken apart and run through level shifters. 

         

      I would like to continue using the USB-UART functionality even when the target is 3.3V powered. 

         

      3) I am unable to tell for certain if a 3.3V powered target will still have 5V tolerant pins. 

         

      Thanks, 
      Karl