I have a custom board, need a date and time datas so I am using PCF2129T with I2C communication. I am using 3.3V CR2032 cells. The problem is that, when I plug a cell lower than 3.3V, system is ok, working properly but if cell's voltage is over 3.3V all datas are being zero, all registers become 0. What could be the problem ? You can see the schematic below, +VBAT is connected to VBAT pin of LPC54608.
Tried it two different modes, results same:
000 : battery switch-over function is enabled in standard mode; battery low detection function is enabled
011 : battery switch-over function is enabled in direct switching mode; battery low detection function is enabled