DP83TC811R-Q1: About the component parameters excluded in datasheet.

NANBING ZHAO

Part Number: DP83TC811R-Q1
Other Parts Discussed in Thread: DP83TC811,

In the datasheet page 113, a Typical Application (RGMII) was given, however, there are some recommended values for DC Blocking capacitor, CM Termination Resistor, MDI Coupling capacitor, and ESD Shunt Resistor. In some example application schematics, they use different values for these components and some designs do not have these components. My question is how to determine if I should put these components in my design and how to calculate these components values in different designs. The second question is I need to know the power consumption of these components since I need to determine the detailed footprint. For example, if I choose a 100K resistor and a 4.7nF capacitor, which footprint I should refer to? 0603? 0805? 1206 or 1210. I think it is important for different voltage supply. So Please tell me where I can find these documents and how to calculate the value of these components and how to determine the detailed footprint. Thank you.

over 5 years ago

0 Cecilia Reyes over 5 years ago

TI__Genius 9920 points

Hello,

Thanks for your interest in the DP83TC811. When you say example schematics, are the examples also using the same TI PHY? You can refer to our EVM as reference for recommendation in component selection. Our BOM should be available for download.

Thanks,

Cecilia

0 NANBING ZHAO over 5 years ago in reply to Cecilia Reyes

Prodigy 30 points

Yes, they use the same TI PHY, all the type is DP83TC811R-Q1. I can refer to your BOM also. However, your BOM shows the 2 schematic use the same value and they use the different footprint. Some schematics use different value of these components. How to determine the values for different designs and footprints? I think it should based on the voltage, current, or power consumption.

0 Cecilia Reyes over 5 years ago in reply to NANBING ZHAO

TI__Genius 9920 points

That is correct, it is based on power and voltage rating. We also take into consideration the form factor on our board placement as well.

Thanks,

Cecilia

0 NANBING ZHAO over 5 years ago in reply to Cecilia Reyes

Prodigy 30 points

Yes, where I can find the these parameters?

0 Cecilia Reyes over 5 years ago in reply to NANBING ZHAO

TI__Genius 9920 points

Hello - Unfortunately we do not have a layout guide for specific components but as a reference larger components with the same valued rating are most likely used for ease of replacement for soldering.

I think your worry should not be about the size of the footprint unless you are limited on space, but making sure that you have the correct ratings similar to the ones listed in the BOMs of our EVMs.

Thanks,

Cecilia

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DP83TC811R-Q1: About the component parameters excluded in datasheet.