DP83867E: Power Dissipation Calculation

Part Number: DP83867E

Hi Team,

I am estimating the power dissipation of the DP83867ERGZ Ethernet PHY for heat sink design.

My understanding is that the total IC power dissipation is calculated from the sum of all supply rail powers:

PD=(VDD2P5×IDD2P5)+(VDD1P0×IDD1P0)+(VDD1P8×IDD1P8)+(VDDIO×IDDIO)

For my case:

• VDD2P5=2.5V, IDD2P5=86mA
• VDD1P0=1.0V, IDD1P0=108mA
• VDD1P8=1.8V, IDD1P8=50mA
• VDDIO=1.8V, IDDIO=24mA

Calculation:

PD=(2.5×0.086)+(1.0×0.108)+(1.8×0.05)+(1.8×0.024)=0.457W

Could you please confirm whether this is the correct approach for estimating DP83867ERGZ power dissipation for thermal calculations?

Thanks.