TPS548A20: Over current protection function

Hirotsugu Kobayashi

Part Number: TPS548A20
Other Parts Discussed in Thread: TPS54A20

Hi, team.

Which is the function Hiccup or Latch-Off when OCP detected of TPS548A20?
It's indicated on a Top page of a data seat with Hiccup, but it also mentioned that Latch-off when UVP detected.

Fig.28 is Hiccup, Fig.29 is Latch-off, Which is true?

Best Regards,

Kobayashi

over 8 years ago

0 Hirotsugu Kobayashi over 8 years ago

Mastermind 9530 points

Hi, team.
When TPS54A20 detected UVP, which is Hiccup or Latch-off?

0 Vental Mao over 8 years ago in reply to Hirotsugu Kobayashi

TI__Expert 5745 points

In an overcurrent condition, the current to the load exceeds the current to the output capacitor thus the output voltage tends to decrease. Eventually, the output voltage crosses the undervoltage-protection threshold and shuts down.

0 Vental Mao over 8 years ago in reply to Hirotsugu Kobayashi

TI__Expert 5745 points

When OVP is detected, latch-off will be occur.

For the UVP, I think John is right, Thank you!

0 JohnTucker over 8 years ago in reply to Vental Mao

TI__Guru**** 191445 points

The datasheet is definitely not clear about this. I am researching the details and will get back to you soon.

0 JohnTucker over 8 years ago in reply to JohnTucker

TI__Guru**** 191445 points

It is definitely hiccup mode. The over current detection and limit is cycle by cycle. When in current limit, the required output current is less than the limited current so the output voltage will decrease. If it decreases below the UVP threshold, then UVP is activated after 1 msec and the TPS548A20 shuts down. It will restart after 40 msec, not latch off.

Power management

Power management forum

TPS548A20: Over current protection function