Hello Group, I'm sorry I don't read all messages in this group and didn't saw that here are questions for me. Thank to Martin Koenig who e-mailed me directly and point this thread to me. What we have so far is the following statistics: In the first 500 pcs assembled boards we had with LPC2106 they were with 10/10 uf tant power supply capacitors and around 10% were with the problem of start-up. The problem was that if you plug and unplug the power supply to the board sometimes the code in LPC2106 is running and sometimes is not running, but oscillator is working in each cases, this happens no matter how long we hold reset low. After the post in this group and the valuable comments from Bill Knight we changed the 3.3V capacitor to 47uF which decreased the boards with problems to only few. Now with over 1700 boards assembled and tested I check today in our QC dept and they have only 6 boards with this problem left, which is too small quantity to worry about and to investigate (say to spend money on it from manufacturing point of view). I can send boards with such problem to Philips to investigate, in matter of fact Robert (philips_apps@yahoo) e-mailed me with such request after my first post. The problem is that this e-mail (tusunov@...) is used only to post on yahoo groups and I don't read it frequently. I read the message about one or two months later and reply to Robert asking for address where to send boards with this problem but never got reply (I suppose he doesn't read his Yahoo e- mail often too :))) Best regards Tsvetan
Message
Re: Power Supply Sequencing - Latchup
2004-07-14 by tsvetanusunov
Attachments
- No local attachments were found for this message.