Hello,
Like others I've used the eval board as a guide in making a custom board. I'm using 3 LiPo batteries to make a 12v battery pack. I've got two problems common to all the boards I've tested that may be related to each other.
First, tying the battery pack voltage (top of the battery stack voltage) to the VAC input voltage to "wake up" the board only works while the connection is make. Once released the board is no longer powered and communication with the BQ40Z60 dies.
Second, Vchg(on) and Vdsg(on), the voltage at the CHG and DSG pins compared to Vbat, go between around -10v when off and -1v when on which is not enough to switch the FETs on. The IC seems to communicate well, the charger works, the voltages seem to be correct, but the battery is never connected to the circuit.
I've been looking at voltages on other pins, VCC, PBI, REGN, and they seem to be okay. Is there something I should be looking for? Any help would be greatly appreciated.
Thanks,
LaMont Dean