AND8349-D Datasheet, PDF (5/6 Pages) ON Semiconductor – Automotive Applications The Use of Discrete

AND8349/D
THERMAL ESTIMATES FOR THE SOD-123 CCR DEVICE
800
700 ^{500 mm2 2 oz}
500 mm² 1 oz
600
300 mm² 2 oz
500
300 mm² 1 oz
400
100 mm² 2 oz
300
P_D max @ 855C
500 mm² 2 oz Cu
500 mm² 1 oz Cu
300 mm² 2 oz Cu
300 mm² 1 oz Cu
100 mm² 2 oz Cu
100 mm² 1 oz Cu
241 mW
228 mW
189 mW
182 mW
117 mW
108 mW
200
100 mm² 1 oz
100
−40 −20
0
20
40
60
80
T_A, AMBIENT TEMPERATURE (°C)
Figure 11. Power Dissipation vs. Ambient
Temperature @ T_J = 1505C for Variable Copper
Heat Spreader
Summary:
Simple, Economical and Robust (SER), the solid state
CCR will allow the user to achieve the expected long life of
their LED array.
CCRs will improve the efficiency and extend the life of
CHMSL LEDs. They will minimize design time and speed
up time to market.
Eliminating the large range of resistor values that must be
uniquely chosen to compensate for the LED’s variation in its
V_fwd is the best benefit to CCR LED biasing.
Since LED brightness is determined by operating current,
optimum intensity will be attained by using a CCR approach
to maintain consistent luminosity over the wide variation of
battery voltage in automotive electrical systems.
SOT−223 package devices are also available which
improve power dissipation. See application note
AND8391/D for a through thermal discussion for both the
SOD−123 and SOT−223 packages.
http://onsemi.com
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