LM74700-Q1: LM74700-Q1 Gate off timing for EN pin high to low transition

Wei-Hao Chen (TW-FAE)

Part Number: LM74700-Q1

Hi team,

What is the LM74700 Gate off delay time for EN pin goes from high to low transition? Datasheet only specified EN pin low to high transition.

And compare to LM5050-Q1, why the LM74700 has much longer delay for both Forward to Reverse Transition and EN delay? 50ns compare to 0.75us?

Thanks a lot.

Best Regards,

Wei-Hao

over 6 years ago

0 Karikalan Selvaraj over 6 years ago

TI__Genius 16305 points

Hello Wei-Hao,

EN Turn OFF delay is specified in "Typical Characteristics" Figure 11. Enable to Gate Delay vs Temperature and it is 28us at 25C.
EN turn ON delay impacts how much time the body diode conducts when enabled and so its specified. Turn off delay given in typical characteristics.
EN delay are not as crucial as reverse turn off and foward turn on delays, but if you are looking for something specific use case let us know.

Turning off faster with 50ns will create more ringing during reverse turn and would need additional clamp to protect from such transients.
0.75 us works good for most of the automotive ISO test cases and ORing power supplies.

Regards,
Kari.

0 Karikalan Selvaraj over 6 years ago in reply to Karikalan Selvaraj

TI__Genius 16305 points

Hello,

Let us know if you have more questions.

If your question is answered, click "this resolved my issue" button at the end.

Regards,
Kari.

0 Wei-Hao Chen (TW-FAE) over 6 years ago in reply to Karikalan Selvaraj

TI__Expert 3260 points

Hi Kari,

Thanks for the explanation.

Many thanks.

Best Regards,
Wei-hao

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LM74700-Q1: LM74700-Q1 Gate off timing for EN pin high to low transition