DP83TC811S-Q1: Power Supply Requirements

Mitchell

Part Number: DP83TC811S-Q1
Other Parts Discussed in Thread: DP83826EVM

Hi Team,

What's the maximum load current the DP83TC811S-Q1 will draw? Is the IDDA-SGMII-ACT a worse case load we should design for?

My customer is trying to select a part to power this chip at 3.3V, but the datasheet it's quite clear on the requirements here. In addition to max current are there any particular noise requirements we need to factor in for the input supply? We are considering using a DC-DC rather than a LDO.

The EVM uses a 1.5A LDO, but we are looking to see if we can move to a lower power part to save on cost.

Thanks,
Mitchell

over 5 years ago

0 Cecilia Reyes over 5 years ago

TI__Genius 9920 points

Hi Mitchell,

What type of MAC Interface will you be selecting? The different current consumption we display in our datasheet is dependent on this.

Once you know the type of interface you can add up the max currents from the I_DDIO and I_DDA max from the Active/Normal modes

Thanks,

Cecilia

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

TI__Genius 9920 points

For example:

if you are selecting 3.3V and using SGMII 6 Wire as the MAC interface, you will have 50mA max for 3.3V operation during Active/Normal Mode AND I_DDA active/normal mode at 135mA. (If you plan on using the same LDO for both of these rails)

As for the DC-DC our new DP83826EVM utilizes a Buck Converter at a lower switching frequency that you can take a look at, and seems to have no effect on EMI/EMC

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DP83TC811S-Q1: Power Supply Requirements