Power dissipation of very samll zise Diode

 

AI Overview shows

"
Power dissipation is the loss of energy in an electrical or electronic system, typically converted into heat.


The power dissipated by a resistor can be calculated using the following formulas, derived from Ohm's Law (V=IR) and the law of heating:

• P = I^2R (Power equals current squared times resistance)
• P = VI (Power equals voltage times current)
  
• P = \frac{V^2}{R} (Power equals voltage squared divided by resistance)

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The second one

• P = VI (Power equals voltage times current)  is Not power dissipated but power generated.

Power dissipation is a time rate of loss of energy.

R (Resistance) must be involved.

 

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The specifications or Dara Sheet of Electronic components usually show Max Power Dissipation as a warning - not to use the part with over Max Power Dissipation (unit Watt) or apply this to the device (component).

 

Recently I ask one Taiwan Schottky Diode supplier what Max Power Dissipation is as the spec does not show this. Their reply was

根据公式PD=(TJ-TA)/热阻=0.15W，谢谢

The Chinese spec is not available.

The English spec shows 

Maximum Thermal Resistance (Note 1) RθJA 650  °C / W

NOTES : 1.Mounted on an FR4 PCB, single-sided copper, mini pad 

 

根据公式PD=(TJ-TA)/热阻=0.15W，

TJ -TA = Temp junction - Temp ambient
热阻 = Thermal Resistance 

Temp junction must be max allowable but not shown in the spec.
Temp ambient 20/25 °C but not shown in the spec.

0.15W canbe come from like

(125 - 25)./ 650 = 0.1538

 

 

 

 

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