TPS543620EVM: Question about Overcurrent Protection

Jayden Qiu

Part Number: TPS543620EVM
Other Parts Discussed in Thread: TPS543620

Hi Team,

I am Jayden, I have some question about overcurrent protection when I run TPS543620EVM in the lab.

1. Why the fsw in high current limit is lower than in low current limit when overload happens? As describe in datasheet 7.3.10.1, If the low-side overcurrent threshold remains exceeded for 15 consecutive cycles, the device enters hiccup. Where is the 15 consecutive cycles in the waveform? It seems there is more than 15 consecutive cycles when overload happens and the device is shut down.

2. In the waveform, both with high current limit and low current limit, it seems that the device is shut down when when Vout drops to 0.77V. Is this a coincidence?

Thanks. Hope to get your reply.

4578.Question about TPS543620.pptx

over 2 years ago

+1 Yitzhak Bolurian over 2 years ago

TI__Mastermind 18370 points

Hi Jayden,

TPS543620 will hiccup if the low-side overcurrent threshold remains exceeded for 15 consecutive cycles.
But a high-side overcurrent event resets the counter for this 15 consecutive low-side overcurrent.

That is why depending on the current ripple, in many applications indeed the hiccup starts only when hitting the low output voltage limit.
So this behavior is expected and not a coincidence.

Regards,

Yitzhak Bolurian

0 Jayden Qiu over 2 years ago in reply to Yitzhak Bolurian

TI__Intellectual 1125 points

Hi Yitzhak,

Thanks for your reply. It resolve my issue.

BRs

Jayden

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TPS543620EVM: Question about Overcurrent Protection