Hi Team,
Our customer is evaluating LM25141EVM at the following conditions.
When light load (around 0.01A to 0.5A), the ripple of VOUT is larger than the heavy load(2.0A) and the frequency component of ripple is lower than the heavy load(2.0A).
[Conditions]
-VIN=4.5V to 20V
-VOUT=3.8V
-IOUT is around 0.01A to 2.0A
-fsw=440kHz
-L=6.8uH
-DEMB pin is Low
I understand that this cause is skip cycle mode.
If yes, could you tell me about the questions below?
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[Q1]
They would like to know the current value and mechanism (operation of the internal circuit) to enter the skip cycle mode.
Could you please let us know if you have any information(Document)?
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[Q2-1]
They would like to estimate the frequency component of ripple.
I understand that this frequency depends on various conditions.
Could you please let us know the calculation method?
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[Q2-2]
Does this frequency have the lower limit level?
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[Q3]
Could you give me the information if you have a waveform of the inductor current and switching voltage and output voltage at the skip cycle mode?
According to their evaluation result, VOUT is “saw tooth waveform” at the skip cycle mode.
So, they would like to know whether this behavior is correct.
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Could you tell me your contact details on E2E message?
I can send the customer information.
I’m looking forward to hearing from you.
Regards,
Kanemaru
