# W5500 current consumption calculation

Customer asked us how to calculate current consumption for W5500.
They would like to confirm 2 items please refer attached PDF in detail .

Q1) Is this correct to measure power consumption between 3V3D and 3V3A?
3V3D current and 3V3A Current ＝1) + 2) + 3)?

Q2 ) Please let me know Max value Of current consumption ?

Best Regards

I think you need to explain the issue, not just ask questions in general. You need to know amperage of power supply device to power the W5500 so that there would be no communication failure because of lack of power?

Kirchhoff’s law should apply. But you must take into account that related circuits are not only resistive, and that their power consumption depends on operation being performed. Again, see typical value in the datasheet for reference schematic (typical) application.

I’d like to explain back ground as below.
Customer wants to reduce power consumption of 3.3V DC. Because of cost of regulator IC.
Request

1. `````` Please advise how to measure power consumption for 3,3V DC.
``````

I attached customer circuit and their measurement way.

I try to upload customer circuit but not succeeded.

1. `````` Please send me recommended PCB layout application note or Gerber data example for reference circuit.
``````

Best Regards

Future Electronics
TSM Hiroshi Iwasaki
Yokohama Land mark Tower 30F
Minato Mirai 2-2-1 Nishi-ku, Yokohama, Japan
Zip code : 2208130
Tel : 81-45-224-2155
Fax: 81-45-224-2156

Best Regards

The values ​​in the W5500 Current consumption table are 1) +2) +3).

Do not think 1), 2), 3) separately.

At 100M link, 1)+2)+3) = 132mA is consumed.

The value of MAX is + 10% of the Typ value.

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Could you please let me know the power up and power down sequence for VDD and AVDD ?
Because customer will use two DCDC regulator For VDD and AVDD.
Is this possible to power up and power down both power line simultaneously ?

Best regards

Dear hiroshiiwasaki.

Why does the customer use a regulator to divide VDD and AVDD?

VDD and AVDD must be powered up at the same time.

This is what customers must implement.

Thank you.

Scott

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As a guess - Hiroshi’s customer wants to physically power down PHY through switching AVDD regulator off. Is it allowed for WIZnet products - having VDD present and AVDD absent?

Hi Eugeny.

If VDD is present and AVDD is absent, operation is not guaranteed.

Scott