ns2w095at NICHIA CORPORATION, ns2w095at Datasheet - Page 8

• Manufacturer Part Number: ns2w095at
• Description: Specifications For Nichia Chip Type White Led
• Manufacturer: NICHIA CORPORATION

(4) Application Design Considerations
· In designing a circuit, the current through each LED must not exceed its absolute maximum rating.
· Thermal design of the end product is of paramount importance.
· Please determine the operating current with consideration of the ambient temperature local to the LED
· The equation 1 indicates correlation between Tj and Ta, and the equation 2 indicates correlation
It is recommended to use Circuit B which regulates the current flowing through each LED.
In the meanwhile, when driving LEDs with a constant voltage in Circuit A, the current through
the LEDs may vary due to the variation in forward voltage (V
some LED may be subjected to stresses in excess of the absolute maximum rating.
of the LED when making the system design.
electric power is affected by the thermal resistance of the circuit board and density of LED placement
on the board, as well as other components.
within the maximum ratings given in this specification.
and refer to the plot of Ambient temperature vs. Allowable Forward Current on CHARACTERISTICS
in this specifications. Please also take measures to remove heat from the area near the LED to improve
the operational characteristics of the LED.
between Tj and Ts.
Tj=Ta + Rja W
Tj = Dice Temperature : °C, Ta = Ambient Temperature : °C,
Ts = Solder Temperature (Cathode Side) : °C,
Rja = Heat resistance from Dice to Ambient temperature : °C /W,
Rjs = Heat resistance from Dice to Ts measuring point ≒ 55°C /W,
W = Inputting Power (I
(A)
1
F
V
F
) : W
Tj=Ts + Rjs W
It is necessary to avoid intense heat generation and operate
(B)
The coefficient of temperature increase per input
-7-
2
F
) of the LEDs. In the worst case,
Please consider the heat generation
Nichia STS-DA1-0037
<Cat.No.071122>