Figure 1. Circuit around using TPS63060
The electronic circuit around the prototype using the TPS63060 is shown in Figure 1.
The prototype is being fabricated using an electric double-layer capacitor.
The capacitor is stored at 12V from a constant voltage power supply to the EDLC during the day.
At night, the low-voltage power supply is turned off and power is supplied from the EDLC.
A SoC is connected to the load side and its operating voltage is 5V. It can energize up to 1A.
Since the voltage of the EDLC gradually decreases at night, the TPS63060 is used to supply 5V.
From November 2022 to March 2023, the electronic circuit was used for operational testing.
One of the five units failed.
On-site investigation confirmed that the SoC was not powered on.
We then took the device back to our office to investigate and found that the VOUT was only 0.7V.
When brought back in-house, the EDLC voltage was 4V.
Since VIN is 4V, VOUT should output 5V. However, VOUT was 0.7V.
Next, EDLC was removed from VIN.
Then, when 12V was supplied from the constant voltage power supply, VOUT output 5V.
When the removed EDLC was reattached, VOUT output 5V.
Application Report SLVA769A-April-2016-Revised September 2018 was viewed.
https://www.ti.com/lit/ml/slva769a/slva769a.pdf?ts=1680232836191
According to it, I learned that if the Power Cycle feature is installed, it will not run until the abnormal condition is reset.
Considering the peripheral circuitry, an over voltage on the input side is unlikely.
Also, it is unlikely that the temperature will be higher than the rated value.
However, there is a possibility of overcurrent on the output side.
Is the Power Cycle function ever activated by an overcurrent on the output side?
