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Visitor II
October 27, 2004
Question

supply, help

  • October 27, 2004
  • 3 replies
  • 707 views
Posted on October 27, 2004 at 06:39

supply, help

    This topic has been closed for replies.

    3 replies

    ricardofAuthor
    Visitor II
    May 17, 2011
    Posted on May 17, 2011 at 12:03

    Here I have attached the electric circuit of my board, and it is impossible that the uPSD start, someone can help me ? I know thw uPSD doesn´t start because it doesn,t give the initial reset in the pin PB0 ( pin 52)

    Visitor II
    May 17, 2011
    Posted on May 17, 2011 at 12:03

    HansDK,

    I'm not sure he needs a reset generator, does he? The uPSD32XX chips have a built-in LVR generator that holds the chip in reset for 10ms after the reset threshold voltage is crossed. All he really needs to do is get his Vcc ramp to take less than 10ms to get from the threshold to full scale, right?
    Visitor II
    May 17, 2011
    Posted on May 17, 2011 at 12:03

    I think you're right, the problem is almost certainly that very large capacitor.

    The reset will work without a reset supervisory circuit, so unless there's a good reason to use it, there's no need for it.