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TSZ02201-0RDR0GZ00190-1-2

© 2014 ROHM Co., Ltd. All rights reserved.

30.Sep.2015 Rev.002

www.rohm.com

TSZ22111 • 15 • 001

BU4S71G2

Typical Performance Curves - continued

Power Dissipation

when it consumed power, and the temperature of IC chip becomes higher than ambient temperature. The temperature that

can be accepted by IC chip depends on circuit configuration, manufacturing process, and consumable power is limited.

Power dissipation is determined by the temperature allowed in IC chip(maximum junction temperature) and thermal

resistance of package(heat dissipation capability). The maximum junction temperature is typically equal to the maximum

value in the storage temperature range. Heat generated by consumed power of IC radiates from the mold resin or lead

frame of the package. The parameter which indicates this heat dissipation capability(hardness of heat release)is called

(°C/W)

Derating curve in Figure 12 indicates power that can be consumed by IC with reference to ambient temperature. Power that

can be consumed by IC with reference to ambient temperature. Power that can be consumed by IC begins to attenuate at

chip size, power consumption, package, ambient temperature, package condition, wind velocity, etc even when the same of

package is used. Thermal reduction curve indicates a reference value measured at a specified condition.

0.0

0.2

0.4

0.6

0.8

1.0

0

25

50

75

100

125

150

Ambient Temperature [℃]

Figure 12. Derating Curve

Figure 11. Thermal resistance

周囲温度

Ta [℃]

チップ 表面温度

Tj [℃]

消費電力 P [W]

Ambient Temperature [°C]

85

BU4S71G2 (SSOP5)

0

50

100

150

200

250

300

-50

-25

0

25

50

75

100

Ambient Temperature [°C]

Operating Temperature Range

0

50

100

150

200

250

300

-50

-25

0

25

50

75

100

Ambient Temperature [°C]

Operating Temperature Range