Other Parts Discussed in Thread: LP2998, TPS63020,
I recently made this circuit and i am having some weird behavior. I made it as close as the original circuit but i changed the programmed output to reach 5V (R4 and R5, the circuit i need to power runs in 5V). Without load seems to work in most cases but if i had a teensy (80mA more or less) seems like it doesnt reach the 1.8V neccesary to go into the charging stage, It stays around 1.55V. Also the power supply i use says that the circuit consumes around 200mA, but nothing changes. Somehow if increase the voltage to around 5,2V the supercaps start to charge the circuit works as it should, including charging, normal and backup operation.
As i said the only change its the programmed output, but this shouldnt affect because in the pre-charge stage the TPS63020DSJ is not even working. The eFuse should affect this part of the circuit and the LP2998 doesnt show any weird behaviour. Also according to the formula the pre-charge current should be higher than 300mA, but it deosnt go higher than 200mA. There isnt much components involved in the pre-charge stage, and it doesnt seem that the component are broken, in fact the R1, D1 and the LP2998 were replaced and we still got the same results.
Could you help me out with this issue?
Thanks in Advance,