LSF0108: AC Paramters

user4779049

Expert 2375 points

Part Number: LSF0108

Hi team,

Pleaae advice me on my questions bellow:

The LSF0108 datasheet has a paramter named CIoff.

It means the capaciter value when the FET switch is turned off.

Q1. Can you let me know

(1) this paramter means the capacitor bwteen An pin and Bn pin, or

(2) capacitor bwtween An and GND as well as Bn and GND.

Q2. If answer is (2), can you let me know the capacitance between An pin and Bn pin.

when the FET is in off state.

Mita

3 months ago

0 Jack Guan 3 months ago

TI__Mastermind 47111 points

Hi Mita,

The definitions for the Cio/ Ci values are determined in pages 46 and 47 of this app note: https://www.ti.com/lit/an/szza036c/szza036c.pdf?ts=1761683685842

The capacitance when the device is in the off state is determined below in CIO (off):

Regards,

Jack

0 user4779049 3 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

Thank you for your answer.

Please allow me to confirm my comprehension.

There may be three capacitors in the device as shown bellow.

Does CIO(off) mean the C1 or C2?

If so, can you let me know the estimated value of the C3?

Mita

0 Jack Guan 3 months ago in reply to user4779049

TI__Mastermind 47111 points

Hi Mita,

Let me follow up on this question and get back to you.

Regards,

Jack

0 user4779049 3 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

Thank you for your feedback.

I am loking forard to get the answer.

Mita

0 Joshua Salinas 3 months ago in reply to user4779049

TI__Mastermind 30370 points

Hello Mita,

There will be some delay in our response since Jack is current out of office. Thank you for understanding.

Regards,

Josh

0 user4779049 3 months ago in reply to Joshua Salinas

Expert 2375 points

Josh-san,

Thank you for the syatus information.

I undersant the situation.

Mita

0 Jack Guan 3 months ago in reply to user4779049

TI__Mastermind 47111 points

Hi Mita,

I am still in the process of collecting this data. Will update here once I receive a response, thanks.
Regards,

Jack

0 user4779049 3 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

Thank you f your dayly status update.

There are holidays this week so the wait won't be a pain.

Hoping for an answer.

Mita

0 Jack Guan 2 months ago in reply to user4779049

TI__Mastermind 47111 points

Hi Mita,

I understand. Thanks for clarifying.
Regards,
Jack

0 user4779049 2 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

I wonder if I can get the answer to my question?

Mita

0 Jack Guan 2 months ago in reply to user4779049

TI__Mastermind 47111 points

Hi Mita,

I do not have the information readily available yet.

Regards,

Jack

0 user4779049 2 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

Thank you for yor feedback.

It would be helpful if you could tell me how long I should wait, one week or more?

Mita

0 Jack Guan 2 months ago in reply to user4779049

TI__Mastermind 47111 points

Hi Mita,

I can provide here with an update no later then 11/14.

Apologies for the inconvenience.

Regards,

Jack

0 user4779049 2 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

Thank you for your feedback.

I am looking forward to get the anser shortly.

Mita

0 Jack Guan 2 months ago in reply to user4779049

TI__Mastermind 47111 points

Hi Mita,

No problem.

Regards,

Jack

+1 Jack Guan 2 months ago in reply to Jack Guan

TI__Mastermind 47111 points

Hi Mika,

Thank you for your patience here.

C3 will also be included in the Cio (on/off) value, though note that as a rough estimate, Cds should be <1pF, which is much lower than C1 and C2 (these include ESD capacitance)

Regards,

Jack

0 user4779049 2 months ago in reply to Jack Guan

Expert 2375 points

Jack-san,

Thank you for the asnwer.

It hleps me a lot.

Mita

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LSF0108: AC Paramters