supply, help

ricardof · ‎2004-10-26

Posted on October 27, 2004 at 06:39

supply, help

ricardof · ‎2011-05-17

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 doesnÂ´t start because it doesn,t give the initial reset in the pin PB0 ( pin 52)

jdaniel · ‎2011-05-17

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?

neil2 · ‎2011-05-17

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.