Dear Technical Support Team,
I am currently analyzing the MP5042 device and have observed behavior that I would like to clarify with you.
According to the datasheet, the output voltage ramp rate is controlled by the dV/dt pin using an external capacitor. When the dV/dt pin is left unconnected, the default ramp rate is specified as approximately 0.9 V/ms.
I have verified this behavior by measurement, and under normal startup conditions the ramp rate indeed corresponds to this value.
However, I am observing a non-standard behavior after short-circuit events:
In some cases, after the output short circuit is removed and the device restarts, the output voltage ramps up significantly faster than the expected 0.9 V/ms default. This faster ramp does not occur consistently, but only occasionally, under otherwise identical conditions.
Key points:
dV/dt pin is left unconnected (no external capacitor)
Normal startup ramp rate matches the datasheet (~0.9 V/ms)
After short-circuit recovery, the ramp rate is sometimes noticeably faster
Supply voltage, load, and ambient conditions are unchanged
My questions are:
Is this behavior expected or documented for MP5042?
Does the device use a different internal startup path or state after short-circuit recovery compared to a cold start?
Are there any known conditions (internal timing, fault latch behavior, internal capacitor pre-charge, etc.) that could explain this behavior?
If needed, I can provide oscilloscope waveforms or additional test conditions.
Thank you for your support and clarification.
Best regards,
Petr Zaborsky
