BU7241G ROHM [Rohm], BU7241G Datasheet - Page 28

• Manufacturer Part Number: BU7241G
• Description: Low Voltage Operation CMOS Operational Amplifiers
• Manufacturer: ROHM [Rohm]

BU7261G,BU7261SG,BU7241G,BU7241SG,BU7262F/FVM,BU7262SF/FVM,BU7242F/FVM,BU7242SF/FVM
BU7461G,BU7461SG,BU7441G,BU7441SG,BU7462F/FVM,BU7462SF/FVM,BU7442F/FVM,BU7442SF/FVM
●Derating curve
© 2009 ROHM Co., Ltd. All rights reserved.
www.rohm.com
2.11 Slew rate (SR)
2.12 Unity gain frequency (ft)
2.13 Total harmonic distortion + Noise (THD+N)
2.14 Input referred noise voltage (Vn)
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 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.190 (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 :
Derating curve in Fig.190(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. Fig191(c)-(f) show a derating curve
for an example of BU7261/41family,BU7262/42family.,7461/7441family,7462/7442family.
Indicates the time fluctuation ratio of voltage output when step input signal is applied.
Indicates a frequency where the voltage gain of Op-Amp is 1.
Indicates the fluctuation of input offset voltage or that of output voltage with reference to the change of output voltage of
driven channel.
Indicates a noise voltage generated inside the operational amplifier equivalent by ideal voltage source connected in series
with input terminal.
Chip surface temperature Tj [℃]
Power dissipation P [W]
θja ＝ (Tj － Ta) / Pd [ ℃ /W]
(a) Thermal resistance
Ambient temperature Ta [℃]
θja ＝ (Tj-Ta) / Pd
チップ表面温度 Tj[ ℃ ]
周囲温度 Ta[ ℃ ]
消費電力 P[W]
パッケージ表面温度 Ta[ ℃ ]
Package surface temperature [℃]
Fig. 190 Thermal resistance and derating
[℃/W]
Power dissipation of LSI [W]
28/32
Ambient temperature Ta [℃]
・・・・・ (Ⅰ)
P2
P1
0
Pd(max)
25
[W]
(b) Derating curve
θja1
50
75
BU7462/BU7442
Tj(max)
θja2 <θja1
100
θja2
125
Tj(max)
Technical Note
2009.05 - Rev.A