AVR-Chat

Brian,
I'm guess you've got another problem; just applying 5 volts to an input without VCC applied shouldn't blow things up.  For example, I've connected a STK500 for programming a processor but didn't have power applied; no damage.

What are these inputs?

Regards,


Tim Gilbert
JEM Innovation Inc.
303-926-9053 (office)
303-437-4342 (cell)
720-890-8582 (fax)
www.jeminnovation.com
www.pdksolutions.com

  ----- Original Message ----- 
  From: Brian 
  To: AVR-Chat@yahoogroups.com 
  Sent: Tuesday, July 28, 2009 8:40 PM
  Subject: [AVR-Chat] AVR inputs


    I made a module for a car to monitor inputs. Since inputs can only be VCC +/-0.5V for a high signal, how do you keep the inputs from getting to the micro before VCC is applied? It keeps blowing my inputs so they dont work.

  One thing I thought about is using a mosfet switch controlled by an output of the micro to allow the signal only once it is started up.

  Brian



  

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