NVCUQ072A datasheet(21/46 Pages) NICHIA

21 / 46 page

NICHIA STS-DA1-5429A <Cat.No.181204>

(6) Thermal Management

● When designing, the derating characteristics (i.e. Thermistor Temperature vs. Allowable Forward Current) must be considered.

The increase in the temperature of an LED while in operation may vary depending on the heat sink’s thermal resistance and the

density of LEDs in the system/assembly. Ensure that when using the LEDs for the chosen application, heat is not concentrated in

an area and properly managed in the system/assembly to ensure the derating characteristics during actual use.

● Use the thermistor temperature (T

TH) to determine the operating current for the chosen application and optimize the thermal

design (e.g. selecting a proper heat sink, thermal interface material, etc.) accordingly.

● The following two equations can be used to calculate the LED junction temperature:

1) TJ=TTH+RθJTH･W

2) TJ=TC+RθJC･W

*TJ=LED Junction Temperature: °C

TTH=Thermistor Temperature: °C

TC=Case Temperature(back surface of LED): °C

RθJTH=Thermal Resistance from Junction to TTH Measurement Point: °C/W

RθJC=Thermal Resistance from Junction to TC Measurement Point: °C/W

W=Input Power(IF×VF): W

● Once the LEDs have been attached to a heat sink, it is difficult to measure T

C due to the location of the TC measurement point.

Refer to the relevant application notes for a method of determining the TJ by measuring TTH. To access the application notes,

go to the Technical Suggestions And Recommendations section of Nichia's website.

● Refer to the relevant application notes for detailed information (e.g. how to handle the COB LEDs, the effect of

adhesion strength between the COB and the heat sink, thermal design considerations, etc.). To access the

application notes, go to the Technical Suggestions And Recommendations section of Nichia's website. Note that the

application notes may be updated, revised, modified and supplemented without notice.

● To determine the thermal resistance (RθJTH), use the following data/equation.

y = 0.07 e4.37 x

0.00

0.10

0.20

0.30

0.40

0.50

0.00

0.10

0.20

0.30

0.40

0.50

Derating1

サ

ス温度変化量/投入電力 ℃/W

TH )

A mount of C hange in T emperature of T hermistor (T

/I nput P ower (°C /W)

NVCUQ072A Datasheet(PDF) 21 Page - NICHIA CORPORATION

NVCUQ072A Datasheet(HTML) 21 Page - NICHIA CORPORATION

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

Datasheet Download

Link URL