TUSB4020BI: Timing of applying external clock of 24MHz to XI pin when power-on

toshi-e2e

Part Number: TUSB4020BI

Hi all,

In case of applying an external clock of 24MHz to XI pin, is there any sequence between power supply and applying an external clock when power on?

Is it possible to apply an external clock to XI pin during VDD/VDD33 = 0V? If no, please let me know the timing of applying an external clock and GRSTz.

Currently, GRSTz is connected to GND thru 1uF cap.

Regards,
Toshi

over 7 years ago

0 Malik Barton57 over 7 years ago

TI__Guru 64326 points

Toshi,

We suggest not having the clock on the XI pin while VDD/VDD33 = 0V but the clock does need to be asserted running by the time GRSTz is deasserted. The clock and the power rails can ramp up at the same time.

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TUSB4020BI: Timing of applying external clock of 24MHz to XI pin when power-on