Posted on May 17, 2011 at 12:08I designed a prototype PCB to convert analog signals by the ADC of uPSD and a stand-alone 10-bit serial ADC chip with same connection to AVCC/VREF, AGND. I tries to use ADC of uPSD3334D-40U6 (5V version) first. The data from the uPSD is noisy and uPSD picks up RFI noise easily. So I switch to use other standalone 10 bit ADC device and the data is very stable and not interfered by RFI.
From the uPSD data sheet, 5V version of PSD is 5V tolerant only at Port 3 and 4. Can Port 1 pin be damaged by 5V signal if it is configured as GPIO pins and has 100K resistor (with 0.1uF by-pass capacitor to AGND) between pin and signal?
