On Nov 8, 2010, at 5:34 PM, Andy Ibbotson wrote: > > One small problem I have is how to get 5V output on the P3 / P4 pins. I can > only get 3.3V at present - can anyone help with jumper settings please? > Regards > Andy
Below is what Peter Wallace suggested to me when I wanted to drive some relays at 5v. This has worked fine for me, btw. -Tom > The 7I43 FPGA is a 3.3V device. Its outputs will only swing to 3.3V. What > kind of relays are you driving? The 7I43 will only drive 24 mA maximum so its > not suited to driving mechanical relays directly. > > If you have a 5V device (thats draws less than 24 mA) you need to drive, it > is possible. > > What you do is this: > > 1. Jumper 7I43 for 5V tolerant I/O > > 2. Connect your load referred to 5V (load+ to 5V load- to 7I42) > This means the output will be active low (normally desirable so its off at > power up) > > 3. Set the output bit to open-drain mode ------------------------------------------------------------------------------ The Next 800 Companies to Lead America's Growth: New Video Whitepaper David G. Thomson, author of the best-selling book "Blueprint to a Billion" shares his insights and actions to help propel your business during the next growth cycle. Listen Now! http://p.sf.net/sfu/SAP-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
