W5500 current consumption calculation

Question

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

Eugeny · Answer

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? hiroshiiwasaki: 3V3D current and 3V3A Current ＝1) + 2) + 3) 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.

scott · Answer

Sorry for reply. 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.

scott · Answer

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

Eugeny · Answer

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

scott · Answer

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

hiroshiiwasaki · Answer

Hello Scott –san, thank you for your advice. I tell customer to ON OFF VDD and AVDD at the same time. Customer measure current consumption of VDD and AVDD and the result is bigger than data sheet. So, they consider to prepare Voltage regulator individual. Best Regards