Datasheet

Technical Note
19/24
BA10393F,BA10339F,BA10339FV,BA2903SF,BA2903SFV,BA2903SFVM,BA2903F,BA2903FV,
BA2903FVM,BA2901SF,BA2901SFV,BA2901SKN,BA2901F,BA2901FV,BA2901KN,BA8391G
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2010.12 - Rev.
A
© 2010 ROHM Co., Ltd. All rights reserved.
0
200
400
600
800
1000
0255075100125
周囲温度
Ta [°C]
許容損失
Pd
[mW]
0
200
400
600
800
1000
0 25 50 75 100 125 150
周囲温度
Ta [°C]
許容損失 Pd [mW]
0
200
400
600
800
1000
0 25 50 75 100 125 150
周囲温度
Ta [°C]
許容損失 Pd [mW]
0
200
400
600
800
1000
0 25 50 75 100 125
周囲温度
Ta [°C]
許容損失 Pd [mW]
●Derating curves
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 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 thermal
resistance, represented by the symbol θja [℃/W].The temperature of IC inside the package can be estimated by this thermal
resistance. Fig.114 (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.114 (b) indicates 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 iis 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.115(c) ~ (f) shows a derating curve for an example of BA8391, BA10393, BA10339,
BA2903S, BA2903, BA2901S, and BA2901.
(*16) (*17) (*18) (*19) (*20) (*21) (*22) (*23) (*24) Unit
6.2 7.0 4.9 6.2 5.5 4.7 7.0 5.3 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.
105
105
0
200
400
600
800
1000
0 25 50 75 100 125
700mW(
★
17)
490mW(
★
18)
BA2903F
BA10339FV
BA10339F
BA2901KN
POWER DISSIPATION Pd [mW] POWER DISSIPATION Pd [mW] POWER DISSIPATION Pd [mW]
POWER DISSIPATION Pd [mW]
Ambient Temperature [℃] Ambient Temperature [℃]
Fig.115 Derating curve
Fig.114 Thermal resistance and derating curve
(c)BA10393 family
(d)BA10339 family
(e)BA2903 family
(f)BA2901 family
620mW(
★
16)
780mW(
★
19)
690mW(
★
20)
590mW(
★
21)
870mW(
★
22)
660mW(
★
23)
610mW(
★
24)
BA10393F
BA2903FV
BA2903FVM
BA2901FV
BA2901F
BA2903SFV
BA2903SF
BA2903SFVM
BA2901SFV
BA2901SKN
BA2901SF
(b) Derating curve
(a) Thermal resistance
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]
Chip surface temperature
Power dissipation
Ambient temperature
0507510012515025
P1
P2
Pd (max)
LSI
の消費電力
[W]
θ' ja2
θ' ja1
Tj ' (m ax )
θja2 < θja1
周囲温度
Ta [
℃
]
θ ja2
θ ja1
Tj (m ax )
Power dissipation of LSI
Ambient temperature
Ambient Temperature [℃] Ambient Temperature [℃]