W5500 temperature


#1

Hey wiznet guys

The W5500 in 100mbit mode uses quite some current, and it gets a little bit warm, and in my environment i could be afraid that it gets too warm. Is it possible to get information about the IC temperature like in some other chips ?
What happens if the chip gets too warm? does it power down or does it continue till it dies?

Another solution for me could be to run in 10mbit, but that causes some other problems because of auto negotiation disabled. I tried to set it to 10mbit full duplex, but my switch detected it as 10mbit half duplex, so with heavy traffic problems occurs. Is it possible to limit the chip to 10mbit but keep auto negotiation on ?

Thanks in advance
\kresten


#2

We understood what you worried about.

W5500 is tested on 85 degree for all samples.
Also we did realiablity test as belows.
So you can use whatever you want, either 100M or 10M.
W5500 temperature will go up arround 45 degree when it operates.
We are sure it is no problems.

For example, the operating tempature of our previous devices went up to arround 70 degree.
It also doesn’t make any problems for more than 10 years on the field.
I mean it was proven by many our customers.
Thanks,

WIZnet.

-------- belows ------------------------------------------------------------------------------------
High Temperature Operating Life test
The high Temperature Operating Life (HTOL) or steady-state life is performed to determine the reliability of devices under operation at high temperature conditions over an extended period of time. It consists of subjecting the parts to a specified bias or electrical stressing, for a specified amount of time, and at a specified high temperature.
Conditions
User Temp (TU) 55 °C Test Temp (TA) 125 °C
User Voltage (VU) - Test Voltage (VA) -
Activation Energy (Eaa) 0.7 γV = ( K/X ) -
Sample Size (N) 77 failures (f) 0
Test duration (tA) 504 tlift (for ppm) 12 month

Life estimate is calculated on the assumption that 1) Gate short to source or drain *, 2) User temp is 55 °C.

  • Failure Mode: Gate short to source or drain
  • Failure Mechanism: Intrinsic breakdown; for gate oxide thickness > 4nm
  • Eaa = 0.7 (activation energy reference “JEP122D”)

----------Calculation-------------------------------------------------------------------------------------------------------------------------

Acceleration Factor (AF) = exp{(Eaa/k)(1/Tuse – 1/Ttest)}
Where
Eaa = apparent activation energy in eV/atom
K = Boltzmann’s constant (8.62 × 10-5 eV/K)
Tuse = use temperature in kelvins
Ttest = Test temperature in kelvins

= exp[(0.7/k) × (1/328 – 1/398)] = 77.94
∴ Test time = AF × Test Time = 77.94 × 504 = 4.48 years

If Exponential distribution (FIT Calculation)
The degrees of freedom = 2, and χ2 = 1.83 @ CL 60%
Failure rate (in FIT) = 109 × χ2 c,d / (2 × AF × N × tA)
= 109 × 1.83 / (2 × 77.94 × 77 × 504) = 303 FIT

∴ Failure Rate (in ppm, 12 months) = 2689 ppm during the first 12 months of usage.
∴ MTTF = 371.9 years