Posted on April 06, 2006 at 15:10We use st10f269f269z2q3 in one of our product and experiencing a strange problem. The ADC VAref(pin37) is internal short to ground (few ohm) and drags connected 5V supply to ground. I use lm340 regulator to supply the 5V to VAref and VAGND(pin 38) connects to analog ground instead of digital ground. When this happens VAref voltage is alomost zero, but the rest of function inside chip still working,. Why could cause this damage and how do we prevent this?
