UCC23513: input resistor on both anode and cathode?

Howard Zou

Genius 12365 points

Part Number: UCC23513

Hi,

in our typical application, we put input resistor on both anode and cathode.

In SI8261's typical application, they only put input resistor on anode.

Can we put resistor only on anode for UCC23513?

What's the benefit of putting input resistor on both anode and cathode?

over 5 years ago

0 Mamadou Diallo over 5 years ago

TI__Genius 13445 points

Hello Howard,

Thanks for reaching out.

Yes you may have a single resistor on anode as shown on Figure 17 in the datasheet so long as you size the resistor appropriately to have the forward bias current within the recommended range.

For guidance on choosing this resistor value, please see refer to app notes below:

https://www.ti.com/lit/an/slua912a/slua912a.pdf

Please let us know if you have additional questions.

Regards,

-Mamadou

0 Don Dapkus over 5 years ago in reply to Mamadou Diallo

TI__Guru**** 189401 points

Hi, Howard,

Also, we have a spreadsheet calculator available in the product folder to help you with the selection of the resistor based on the circuit conditions.

If we answered your question, please press the green button. Otherwise, let us know what else you need.

0 Howard Zou over 5 years ago in reply to Don Dapkus

TI__Genius 12365 points

Don,

thank you.

Are there any benefit of using 2 input resistors instead of one?

I have read the paper you offered but can't find the answer.

0 Mamadou Diallo over 5 years ago in reply to Howard Zou

TI__Genius 13445 points

Hi Howard,

The split resistors are generally common with applications using NMOS FETs on the cathode therefore a resistor there helps with possible power dissipation at the junction of the FET.

In addition to the high CMTI ratings, the split resistors across the e-diode also helps with common-mode noise rejection by limiting GND common-mode transients during switching cycles of the power transistors.

Regards,

-Mamadou

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UCC23513: input resistor on both anode and cathode?