TLV61046A: “soft start time” vs “startup time”

Kurumi Hasegawa

Expert 7891 points

Part Number: TLV61046A

Hi team,

What is the difference between “soft start time” and “startup time”?

The datasheet states “startup time” is 5ms typ, and “soft start time” is 7ms typ.

What makes the difference?

Best regards,

Kurumi

over 3 years ago

+1 Eric Yue over 3 years ago

TI__Expert 5180 points

Hi Kurumi,

For TLV61046A, at the beginning of start up period, the isolation FET is turned on slowly to charge the output capacitor with 30-mA current for about 2 ms. This is called the pre-charge phase. After the pre-charge phase, the TLV61046A starts switching. This is called switching softstart phase. The switching soft start phase is about 5 ms typically. Therefore, soft start time is 7ms typ. Detailed information can be found in 7.7.3 of datasheet.

Best Regards,

Eric Yue

0 Kurumi Hasegawa over 3 years ago in reply to Eric Yue

TI__Expert 7891 points

Hi Eric,

OK, so if my understanding is correct, startup time is a portion of soft start time which is called switching soft start phase. I tried to summarize relationship of those terms, please see below figure. Is it correct?

Best regards,

Kurumi

+1 Eric Yue over 3 years ago in reply to Kurumi Hasegawa

TI__Expert 5180 points

Hi Kurumi,

Yes, I think your understanding is right.

0 Kurumi Hasegawa over 3 years ago in reply to Eric Yue

TI__Expert 7891 points

Hi Eric,

Understood, thank you so much!

Best regards,

Kurumi

0 Eric Yue over 3 years ago in reply to Kurumi Hasegawa

TI__Expert 5180 points

Hi Kurumi,

Thanks for the update, please notice me if there is anything more needed from my side.

Best Regards,

Eric Yue

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TLV61046A: “soft start time” vs “startup time”