Post by thread:[PICLIST] pic 16c622, low voltage operation

Hi, i have a circuit that must be operated about 3.6 v. the first version for simplicity was done at 5v and its works ok, but when i down the supply to 3.6 v, things go wrong. the program show 3 pairs of digits in a two 7 segment, comun catode led display, using 2 port for column scanning and 7 bits of a port for the 7 segment. what is show is saved in 6 bytes, showing first the first two, then the next two, next the last two and finally a pause in off. when i lower the supply, it not advance to the next pair of two segment, but still does the column scanning showing the two digits alternating. at 4.3 v it works fine, and the device is windowed. the BOR is disabled. the xtal is 3.579 Mhz, coupled with 22 pf capacitor. I assume that the device is working, because is showing alternating the first two digits, but it is perhaps reseting and starting again and again. what is wrong?, any help will be appreciated. sorry for my bad english. Rodrigo Valladares P. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

the brown out (BOR) must still be enabled. according to the data sheet it will reset the chip somwhere between 3.7 and 4.3 volts. which seems to match your problem > i have a circuit that must be operated about 3.6 v. the first version for > simplicity was done at 5v and its works ok, but when i down the supply to > 3.6 v, things go wrong. > > at 4.3 v it works fine, and the device is windowed. the BOR is disabled. the > xtal is 3.579 Mhz, coupled with 22 pf capacitor. I assume that the device is > working, because is showing alternating the first two digits, but it is > perhaps reseting and starting again and again. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics