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Part Number: LM2623
Our customer would like to know the behavior of LM2623ALD when VDD is less than 0.8V(VIN_OP).
Could you please let us know if you have any information?
If VDD is less than 0.8V(VIN_OP), Does this device stop switching?
After Q1 case, If VDD rise to 0.8V, does this device restart switching as the current limit is working?
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In reply to Youhao Xi:
Thank you for the information.
According to our customer, a big load transient occurs, and the input voltage may be reduced(around 0.8V) in their application.
Therefore, they would like to know about Q1 and Q2.
I understand that this device does restart the switching as the current limit is working.
Is my understanding correct?
[Their concern point]
For example, if the input voltage reaches around 0.8V by a big load transient.
Then, LM2623A stops by UVLO and can’t restart the switching from the input voltage is around 0.8V.
Because, LM2623A need the input voltage 1.1V to start-up.
I’d greatly appreciate your verification.
In reply to hideto kanemaru:
Thank you for your response.
Please contact me when you receive the information from designer’s.
And, with my understanding, I guess that it will be as written below.
Would you tell me about the progress on this matter?
I would appreciate your prompt reply.
I’m sorry to bother you despite your business, but I would appreciate your consideration.
Thank you for the detail information.
And, I have some questions.
Could you please let us know the measurement condition of LM2623A EVM?
-Under load = ??A
We would like to know the current limit when the low voltage startup.
I understand that if VDD is more than 1.1V, On start-up, the control circuitry switches the N-channel MOSFET continuously until the output reaches VDD is 3V.
Then, can the cycle-by-cycle peak current limit function?
If we can use this device at the following condition.
Then, we don't have to care “VDD_ST=1.1V”.
So, LM2623 operates(switching) unless VIN reaches around 0.8V.
Thank you always for your kind support and response.
I will report this information to our customer.
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