I'm having an issue with the ADP5090 startup sequence with some of my PCB's. Some of our PCB's came back not working. I use the ADP5090 to charge and manage a small 25 mAh Lithium polymer battery and use RFID Vout to as Vin for the ADP5090. This works fine on most of the PCB's but some the ADP5090 never achieves a stable SYS voltage as shown in the measurement below:
Note: Voltages are a bit higher than in real life due to max setting on scope.
More zoomed in on the issue. SYS reaches a good voltage but than collapses back to the End of Cold-Start Operation Threshold.
This is the schematic used:
Hope anyone can point me in the right direction of this issue.