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Power Management

Q&A LTC3866 and LTC3851A, Question about external clock signal for synchronization

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LTC3866 and LTC3851A, Question about external clock signal for synchronization

Kazu on Nov 19, 2021

Hi,

I have some questions about the external clock signal for synchronization to MODE/PLLIN pin.

I'm considering designing an external clock signal with frequency of 400kHz to 700kHz and ON time of 75ns to 500ns.

- Is there any problem with the ON time period?

- Please let me know the specifications of the ON time.

Regards,

Kazu

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mike.shriver
Nov 23, 2021 in reply to mike.shriver +2 verified
Hello Kazu,

For the external clock signal driving the MODE/PLLIN pins of the LTC3866 and LTC3851A:
- Keep the on-time and off-time greater than 100nsec.
- The maximum allowable low clock level is 0.5V & the…

0 Kazu on Nov 23, 2021 12:13 AM

Hi,

Could someone take care of this case?

Regards,

Kazu
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0 mike.shriver

on Nov 23, 2021 4:19 AM in reply to Kazu
Hello Kazu,

I will ask the designers.

Best regards,

Mike
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+1 mike.shriver

on Nov 23, 2021 11:24 PM in reply to mike.shriver
Hello Kazu,

For the external clock signal driving the MODE/PLLIN pins of the LTC3866 and LTC3851A:

Keep the on-time and off-time greater than 100nsec.

The maximum allowable low clock level is 0.5V & the minimum allowable high clock level is 2.0V.

The high clock level should not exceed INTVCC and the low clock level should not go below -0.3V. These limits are the specified absolute maximum ratings for the pin on both parts.

Best regards,

Mike
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