TUSB2077A: RESET Pulse

K.Hamamoto

Guru 12155 points

Part Number: TUSB2077A

On the datasheet, it is mentioned as the following,

I have some simple questions about above sequence.

1.Is that meant that we must input the reset pulse(low pulse) for 100us~1ms after 3.3V reached its 90%?

2.What happen if that pulse exceed 1us?

Regards,

Koji Hamamoto

over 8 years ago

0 Joel Jimenez0 over 8 years ago

TI__Mastermind 18655 points

Hello

A pulse of 1us is too short. If the hub is held in reset for a longer or shorter period of time, it can fail to respond promptly to USB host signaling and not complete enumeration. This is typically an issue with embedded system applications.

0 K.Hamamoto over 8 years ago in reply to Joel Jimenez0

Guru 12155 points

Hi Joel-san,

I am sorry for my typo.

Regarding Q2, it was

2.What happen if that pulse exceed 1ms?

As you mentioned above, the longer period(>1ms) of time it will be possibility to occur failing to respond promptly to USB signaling and not complete enumeration.

Is that correct?

Regards,

Koji Hamamoto

0 Joel Jimenez0 over 8 years ago in reply to K.Hamamoto

TI__Mastermind 18655 points

Hi Koji-san,

Yes, you are correct.

Regards

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TUSB2077A: RESET Pulse