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BD5460GUL
www.rohm.com
2010.06 - Rev.A
© 2010 ROHM Co., Ltd. All rights reserved.
Technical Note
●About the thermal design by the IC
Characteristics of an IC have a great deal to do with the temperature at which it is used, and exceeding absolute maximum
ratings may degrade and destroy elements. Careful consideration must be given to the heat of the IC from the two
standpoints of immediate damage and long-term reliability of operation. Pay attention to points such as the following.
Since an maximum junction temperature (Tjmax.) or operating temperature range (Topr) is shown in the absolute maximum
ratings of the IC, to reference the value, find it using the Pd-Ta characteristic (temperature derating curve).
If an input signal is too great when there is insufficient radiation, TSD (thermal shutdown) may operate.
TSD, which operates at a chip temperature of approximately +180
℃, is canceled when this goes below approximately
+100
℃.Since TSD operates persistently with the purpose of preventing chip damage, be aware that long-term use in the
vicinity that TSD affects decrease IC reliability.
Temperature Derating Curve
Power dissipation values vary according to the board on which the IC is mounted. The Power dissipation of this IC when
mounted on a multilayer board designed to radiate is greater than the values in the graph above.
Note) Values are actual measurements and are not guaranteed.
Reference data
1.5
1.0
0.5
0.0
0 25 50 75 100 125
150
Ambient Temperature Ta(
℃)
Power Dissipation Pd (W)
0.69W
measurement conditions ： IC unit and Rohm standard board mount
board size ： 50mm×58mm
θja = 181.8℃/W
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