1 Reply Latest reply on Apr 9, 2010 4:42 PM by userc_39275

    The Output Current of CY7C68013A

              I am using CY7C68013A in my design.According to the datasheet of CY7C68013A,the output current is no more than 100mA.But it is nearly 300mA now.Who can kindly help me answer the problem?The circuit only includes CY7C68013A.Is the problem that the IC I bought is fake?According to the datasheet of CY7C68013,the output current is more than 200mA.   
        • 1. Re: The Output Current of CY7C68013A
                  What do you mean, "output current"? There are several.   
          - Per pin output current is 4 mA sink/source, max   
          - Per port output current is 10 mA   
          - All ports together can use no more than 50 mA   
          From your statement, I think you mean "current used by the device". The USB specification says that any device attaching to the USB may only use at most 100 mA of host current; the device must than ask for permission to use up to 500 mA of host current. Self-powered devices do not have this limitation.   
          One reason Cypress made an FX2LP to replace the FX2 is because the FX2's minimum current requirements exceeded the USB specification during Enumeration. There was even a work-around that involved booting into Full Speed mode (which consumes less current than High Speed mode) getting permission for more current, and then re-enumerating as a high speed device.   
          I think this is probably the origin of your "no more than 100 mA" comment. If you power down everything but the stuff needed for Enumeration, it uses less than 100 mA. Once Enumerated you can turn I/O's on and start drawing more power.