Other Parts Discussed in Thread: BQ500511, BQ50002
I have recently designed a wireless TX charger based on the BQ50002 + BQ500511 reference designs and the first version was 100% successful. The second version however has about a ~50% pass rate.
After debugging some hardware, it seems like the BQ50002 oscillator is not working because there is not CLK_OUT signal present, but on working boards it is there and at the same frequency as the PWM logic inputs. Our mode pin is low and the EN and PWM inputs are at switching frequency (I can attach oscilloscope shots later if you need more detail). Is there any reason why only half of the BQ50002s would be working? I am starting to assume this was a possible fabrication issue....reflow temp is 260C and we flowed around 240-250. I can't think of anything else at the moment....
Let me know if you have any ideas or have seen this behavior before...