3 Replies Latest reply on Oct 29, 2012 2:53 PM by user_14586677

    Rating of diodes in PSoCpins

    srihari.s

       Out of curiosity one more question.

         

      What is the rating of diodes in the Pin structure of PSoC. For sure they are meabt for ESD. Any idea on what are their ratings.

        • 1. Re: Rating of diodes in PSoCpins
          user_14586677

          The Vil, Vih levels limited to .5V off the rails, and 140 mA limit to

             

          invoke latchup. So these specs effectively would be the characterized

             

          process values safeguarded by some margin.

             

           

             

          Regards, Dana.

          • 2. Re: Rating of diodes in PSoCpins
            srihari.s

            So, if I have voltage of 3.3 + 0.7 (Vddio is of 3.3V) then the signal never enters my pin as the diode shows a very low resistance path for my signal. Am I correct???

            • 3. Re: Rating of diodes in PSoCpins
              user_14586677

              The pin clamps to Vdd +Vthdiode, until you feed too much current into

                 

              it to either trigger the parasitic SCR mechanism, blowing out Vdd bond

                 

              wire internal, or silicon meltdown.

                 

               

                 

              If you do not exceed the current rating then signal looks like a "1" as

                 

              it would normally. For the digital case.

                 

               

                 

              For the analog case, Cypress does not have any stated specs on

                 

              phase reversal on OpAmps when their inputs are driven outside

                 

              their CM range. You would have to test for that.

                 

               

                 

              Regards, Dana.