LM73605-Q1: Recover time of over-current and over-temperature

Ansel Song

Expert 3890 points

Part Number: LM73605-Q1

Hi team,

As written in the data sheet of LM73605-Q1: it has over-current protection and thermal shutdown protections.

But our customer wants to know the recovery time of over-current and overheating.

For example, the thermal shutdown is 160℃, and the recovery threshold is 135℃.

So how long can it return to normal output when the temperature is lower than 135℃ ? Similarly, what about the recovery time of over-current protection?

Thanks.

Best regards,

Ansel Song

over 5 years ago

0 Iven Su over 5 years ago

TI__Expert 8245 points

Hi,

Actually the recover time is not easy to estimate because the device detects temperature on the junction inside, but it takes some time to transfer the temp from case to junction. Also, it depends on the rate of temperature drop, layout of the board, etc. The detection time is much shorter than this. Also as to over-current recovery, it is the same and mainly depends on your load rate, inductor, etc

0 Ansel Song over 5 years ago in reply to Iven Su

TI__Expert 3890 points

Hi Iven,

I agree with you. Have you tested the data on the EVM? Or is there any reference data?

Best regards,

Ansel

0 Iven Su over 5 years ago in reply to Ansel Song

TI__Expert 8245 points

Hi Ansel,

Yes, before we did similar tests on some other converters, it looks no reference data and I think you need to have a specific condition/environment then it makes sense.

0 Ansel Song over 5 years ago in reply to Iven Su

TI__Expert 3890 points

Hi Iven,

Is there an approximate range value? Or the recover time is ns? us? Thanks.

Best regards,

Ansel Song

0 Iven Su over 5 years ago in reply to Ansel Song

TI__Expert 8245 points

Hi Ansel,

For over-current recovery, the total time is [external current recovery time] + [0~46ms typ.(hiccup delay time)] + [soft-start time].

For over-temp recovery, normally the total recover time is ms level if the case temp drops rapidly. But considering whole PCB or system, it really depends.

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LM73605-Q1: Recover time of over-current and over-temperature