1 Reply Latest reply on Jul 8, 2015 9:55 AM by janos

    CY4608M Development Kit - Bug with SELF_PWR mosfet

    janos

      Hi guys,

         

      I got lost using the search function, so I just want to report the bug I've just found to you. Appologies if that has been done before.

         

      In the CY4608M HX2VL 4-port MTT USB 2.0 HUB Development Kit, there is a wrong transistor Q3 used in the schematic design and in the actual assembled board.

         

      Q3 is a FDN338P p-channel MOSFET, but it has to be a n-channel transistor, in order to use the HUB as a self-powered USB device.

         

      Hope this helps.

         

      Cheers

         

      Janos

        • 1. Re: CY4608M Development Kit - Bug with SELF_PWR mosfet
          janos

          Hi guys,

             

          I have to appologize for the "Bug" I have filed. However I was wrong and the Bug is no Bug, i.e. there is nothing wrong with transistor Q3.

             

          The issue came up, when I tried to use the Hub in self-powered mode in a situation where I don't have any voltage on VBUS. I am not sure if that is a valid case for USB design, but in this case the RESET# line is in low-state and the CY7C65642 will stay in reset mode. I am not sure if that is a mistake in the design, or if that case is just invalid.