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參數(shù)資料
| 型號(hào)： | mic5236 |
| 廠商： | Micrel Semiconductor,Inc. |
| 英文描述： | Low Quiescent Current μCap LDO Regulator(低靜態(tài)電流μCap技術(shù)低壓差穩(wěn)壓器) |
| 中文描述： | 低靜態(tài)電流LDO穩(wěn)壓器μCap（低靜態(tài)電流μCap技術(shù)低壓差穩(wěn)壓器） |
| 文件頁數(shù)： | 10/12頁 |
| 文件大?。?/td> | 94K |
| 代理商： | MIC5236 |
MIC5236
Micrel
MIC5236
10
November 2000
C
OUT
V
OUT
V
IN
5V
V
ERR
IN
MIC5236
EN
200k
1N4148
200k
4.7
μ
F
OUT
GND
SHENABLE
ERR
Figure 4. Remote Enable with Short-Circuit
Current Foldback
Thermal Characteristics
The MIC5236 is a high input voltage device, intended to
provide 150mA of continuous output current in two very small
profile packages. The power SOP-8 and power MSOP-8
allow the device to dissipate about 50% more power than
their standard equivalents.
Power SOP-8 Thermal Characteristics
One of the secrets of the MIC5236
’
s performance is its power
SO-8 package featuring half the thermal resistance of a
standard SO-8 package. Lower thermal resistance means
more output current or higher input voltage for a given
package size.
Lower thermal resistance is achieved by joining the four
ground leads with the die attach paddle to create a single-
piece electrical and thermal conductor. This concept has
been used by MOSFET manufacturers for years, proving
very reliable and cost effective for the user.
Thermal resistance consists of two main elements,
θ
JC
(junction-to-case thermal resistance) and
θ
CA
(case-to-ambi-
ent thermal resistance). See Figure 5.
θ
JC
is the resistance
from the die to the leads of the package.
θ
CA
is the resistance
from the leads to the ambient air and it includes
θ
CS
(case-to-
sink thermal resistance) and
θ
SA
(sink-to-ambient thermal
resistance).
θ
JA
θ
JC
θ
CA
printed circuit board
Figure 5. Thermal Resistance
ground plane
heat sink area
SOP-8
AMBIENT
Using the power SOP-8 reduces the
θ
JC
dramatically and
allows the user to reduce
θ
CA
. The total thermal resistance,
θ
JA
(junction-to-ambient thermal resistance) is the limiting-
factor in calculating the maximum power dissipation capabil-
ity of the device. Typically, the power SOP-8 has a
θ
JC
of
20
°
C/W, this is significantly lower than the standard SOP-8
which is typically 75
°
C/W.
θ
CA
is reduced because pins 5
through 8 can now be soldered directly to a ground plane
which significantly reduces the case-to-sink thermal resis-
tance and sink to ambient thermal resistance.
Low-dropout linear regulators from Micrel are rated to a
maximum junction temperature of 125
°
C. It is important not
to exceed this maximum junction temperature during opera-
tion of the device. To prevent this maximum junction tempera-
ture from being exceeded, the appropriate ground plane heat
sink must be used.
0
100
200
300
400
500
600
800
900
0
0.25 0.50 0.75 1.00 1.25 1.50
POWER DISSIPATION (W)
C
2
)
4
°
C
5
°
C
5
°
C
6
°
C
7
°
C
8
°
C
1
°
C
Figure 6. Copper Area vs. Power-SOP
Power Dissipation
(
T
JA
)
Figure 6 shows copper area versus power dissipation with
each trace corresponding to a different temperature rise
above ambient.
From these curves, the minimum area of copper necessary
for the part to operate safely can be determined. The maxi-
mum allowable temperature rise must be calculated to deter-
mine operation along which curve.
T = T
J(max)
–
T
A(max)
T
J(max)
= 125
°
C
T
A(max)
= maximum ambient operating temperature
For example, the maximum ambient temperature is 50
°
C, the
T is determined as follows:
T = 125
°
C
–
50
°
C
T = 75
°
C
Using Figure 6, the minimum amount of required copper can
be determined based on the required power dissipation.
Power dissipation in a linear regulator is calculated as fol-
lows:
P
D
= (V
IN
–
V
OUT
) I
OUT
+ V
IN
·
I
GND
If we use a 3V output device and a 28V input at moderate
output current of 25mA, then our power dissipation is as
follows:
P
D
= (28V
–
3V)
×
25mA + 28V
×
250
μ
A
P
D
= 625mW + 7mW
P
D
= 632mW
From Figure 6, the minimum amount of copper required to
operate this application at a
T of 75
°
C is 25mm
2
.
Quick Method
Determine the power dissipation requirements for the design
along with the maximum ambient temperature at which the
device will be operated. Refer to Figure 7, which shows safe
operating curves for three different ambient temperatures:
25
°
C, 50
°
C and 85
°
C. From these curves, the minimum
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MIC5238-1.1BD5 | Coaxial Cable; Coaxial RG/U Type:11; Impedance:75ohm; Conductor Size AWG:15; No. Strands x Strand Size:19 x 27; Jacket Material:Fluoropolymer; Conductor Material:Copper; Jacket Color:Black; Leaded Process Compatible:Yes |
| MIC5238-1.1BM5 | Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator |
| MIC5238-1.3BD5 | Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator |
| MIC5238-1.3BM5 | Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator |
| MIC5238 | Ultra-Low Quiescent Current, 150mA ?Cap LDO Regulator |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MIC5236_05 | 制造商:MICREL 制造商全稱:Micrel Semiconductor 功能描述:Low Quiescent Current μCap LDO Regulator |
| MIC5236-1.8BM | 功能描述:IC REG LDO 1.8V .15A 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降（標(biāo)準(zhǔn)）:- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制（最小）:- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD，TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH |
| MIC5236-1.8BM TR | 功能描述:IC REG LDO 1.8V .15A 8-SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降（標(biāo)準(zhǔn)）:- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制（最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD，TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH |
| MIC5236-1.8BMM | 功能描述:IC REG LDO 1.8V .15A 8-MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降（標(biāo)準(zhǔn)）:- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制（最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD，TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH |
| MIC5236-1.8BMM TR | 功能描述:IC REG LDO 1.8V .15A 8-MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:500 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式 輸出電壓:12V 輸入電壓:14.5 V ~ 35 V 電壓 - 壓降（標(biāo)準(zhǔn)）:- 穩(wěn)壓器數(shù)量:1 電流 - 輸出:500mA 電流 - 限制（最?。?- 工作溫度:-40°C ~ 125°C 安裝類型:通孔 封裝/外殼:TO-205AD，TO-39-3 金屬罐 供應(yīng)商設(shè)備封裝:TO-39 包裝:散裝 其它名稱:*LM78M12CH*LM78M12CH/NOPBLM78M12CH |
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