Technical Note

BA4558F,BA4560F,BA4558RF/FV/FVM,BA4560RF/FV/FVM,BA4580RF/FVM,

BA15218F,BA14741F,BA15532F,BA4510F/FV,BA2115F/FVM

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2009.05 - Rev.A

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Fig. 233 Derating curve

0

50

75

100

125

150

25

P1

P2

Pd(max)

LSIの消費電力[W]

θja2

θja1

Tj(max)

θja2 < θja1

周囲温度Ta[℃]

θja2

θja1

Tj(max)

’

’

’

Power dissipation of LSI [W]

Ambient temperature Ta [℃]

(b) Derating curve

●

Derating curve

Power dissipation (total loss) indicates the power that can be consumed by IC at Ta=25℃(normal temperature).IC is heated when

it consumed power, and the temperature of IC ship 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 thermal resistance, represented by the symbol θj-a[℃

/W]. The temperature of IC inside the package can be estimated by this thermal resistance. Fig.232 (a) shows the model of thermal

resistance of the package. Thermal resistance θja, ambient temperature Ta, junction temperature Tj, and power dissipation Pd can

be calculated by the equation below :

θja ＝ (Tj－Ta) / Pd

[℃/W]

・・・・・

(Ⅰ)

Derating curve in Fig.232 (b) 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 certain

ambient temperature. This gradient, is determined by thermal resistance θja. Thermal resistance θja depends on 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. Fig.233(a), (b) ,(c) ,(d) show a derating

curve for an example of BA4558, BA4560, BA4558R, BA4560R, BA4580R, BA15218, BA14741, BA15532, BA4510, BA2115.

(*25)

(*26)

(*27)

(*28)

(*29)

Unit

6.2

5.5

4.7

6.2

4.9

[mW/℃]

When using the unit above Ta=25[℃], subtract the value above per degree[℃]. Permissible dissipation is the value

when FR4 glass epoxy board 70[mm]×70[mm]×1.6[mm] (cooper foil area below 3[％]) is mounted.

0

200

400

600

800

1000

0

255075

100

125

150

周囲温度　Ta　[℃]

BA4558RF

BA4560RF

BA4580RF BA4558RFV

BA4560RFV

BA4580RFV

BA4558RFVM

BA4560RFVM

BA4580RFVM

780mW( *1)

690mW( *2)

590mW (*3)

0

200

400

600

800

1000

0

25

50

75

100

125

周囲温度　Ta　[℃]

BA4558F

BA4560F

BA15218F

BA15532F

BA14741F

620mW (*4)

490mW (*5)

0

200

400

600

800

1000

0

25

50

75

100

125

周囲温度　Ta　[℃]

BA4510F

BA4510FV

620mW( *1)

550mW (*2)

(a) BA4510ファミリ

0

200

400

600

800

1000

0

25

50

75

100

125

150

周囲温度　Ta　[℃]

BA2115F

BA2115FVM

780mW (*3)

590mW (*4)

(b) BA2115ファミリ

(a)BA4558R/BA4560R/BA4580R family

(b)BA4558/BA4560/BA15218/BA14741/BA15532 family

(c)BA4510 family

(d)BA2115 family

Ambient temperature [℃]

Ambient temperature [℃]

Ambient temperature [℃]

Ambient temperature [℃]

(a) Thermal resistance

Fig. 232

Thermal resistance and derating curve

周囲温度 Ta [℃]

チップ 表面温度 Tj [℃]

消費電力 P [W]

θja = ( Tj ーTa ) / Pd [℃/W]

Ambient temperature Ta [℃]

Chip surface temperature Tj [℃]

Power dissipation P [W]