- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄358804 > LM1084IT-5.0 (NATIONAL SEMICONDUCTOR CORP) 5A Low Dropout Positive Regulators PDF資料下載
參數(shù)資料
| 型號： | LM1084IT-5.0 |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 基準電壓源/電流源 |
| 英文描述： | 5A Low Dropout Positive Regulators |
| 中文描述： | 5 V FIXED POSITIVE LDO REGULATOR, 1.5 V DROPOUT, PSFM3 |
| 封裝： | TO-220, 3 PIN |
| 文件頁數(shù)： | 9/13頁 |
| 文件大?。?/td> | 750K |
| 代理商： | LM1084IT-5.0 |
Application Note
(Continued)
must be added, one for case to heat-sink (
θ
CH
) and one for
heatsink to ambient (
θ
HA
). The junction temperature can be
predicted as follows:
T
J
= T
A
+ P
D
(
θ
JC
+
θ
CH
+
θ
HA
) = T
A
+ P
D
θ
JA
T
J
is junction temperature, T
A
is ambient temperature, and
P
is the power consumption of the device. Device power
consumption is calculated as follows:
I
IN
= I
L
+ I
G
P
D
= (V
IN
V
OUT
) I
L
+ V
IN
I
G
Figure 6
shows the voltages and currents which are present
in the circuit.
Once the devices power is determined, the maximum allow-
able (
θ
JA (max)
) is calculated as:
θ
JA (max)
= T
R(max)
/P
D
= T
J(max)
T
A(max)
/P
D
The LM1084 has different temperature specifications for two
different sections of the IC: the control section and the output
section. The Electrical Characteristics table shows the junc-
tion to case thermal resistances for each of these sections,
while the maximum junction temperatures (T
) for each
section is listed in the Absolute Maximum section of the
datasheet. T
J(max)
is 125C for the control section, while
T
J(max)
is 150C for the output section.
θ
JA (max)
should be calculated separately for each section as
follows:
θ
JA
(max, CONTROL SECTION) = (125C - T
A(max)
)/P
D
θ
JA
(max, OUTPUT SECTION) = (150C - T
A(max)
)/P
D
The required heat sink is determined by calculating its re-
quired thermal resistance (
θ
HA (max)
).
θ
HA (max)
=
θ
JA (max)
(
θ
JC
+
θ
CH
)
(
θ
HA (max)
) should also be calculated twice as follows:
(
θ
) =
θ
(max, CONTROL SECTION) - (
θ
JC
(CON-
TROL SECTION) +
θ
CH
)
(
θ
) =
θ
JA
(max, OUTPUT SECTION) - (
θ
JC
(OUTPUT
SECTION) +
θ
CH
)
If thermal compound is used,
θ
can be estimated at 0.2
C/W. If the case is soldered to the heat sink, then a
θ
CH
can
be estimated as 0 C/W.
After,
θ
HA (max)
is calculated for each section, choose the
lower of the two
θ
HA (max)
values to determine the appropri-
ate heat sink.
If PC board copper is going to be used as a heat sink, then
Figure 7
can be used to determine the appropriate area
(size) of copper foil required.
10094616
FIGURE 6. Power Dissipation Diagram
10094664
FIGURE 7. Heat sink thermal Resistance vs Area
L
www.national.com
9
相關PDF資料 |
PDF描述 |
|---|---|
| LM1084IT-ADJ | 5A Low Dropout Positive Regulators |
| LM1084ISX-12 | 5A Low Dropout Positive Regulators |
| LM1084ISX-3.3 | 5A Low Dropout Positive Regulators |
| LM1084ISX-ADJ | 5A Low Dropout Positive Regulators |
| LM1084IS-ADJ | 5A Low Dropout Positive Regulators |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LM1084IT-ADJ | 功能描述:低壓差穩(wěn)壓器 - LDO RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓（最大值）:307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20 |
| LM1084IT-ADJ/NOPB | 功能描述:低壓差穩(wěn)壓器 - LDO 5A LDO POS REG RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓（最大值）:307 mV 輸出電流:1 A 負載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-20 |
| LM1084IT-ADJ/NOPB | 制造商:Texas Instruments 功能描述:Linear Voltage Regulator IC |
| LM1084M | 制造商:SEME-LAB 制造商全稱:Seme LAB 功能描述:5 AMP POSITIVE |
| LM1084R | 制造商:HTC 制造商全稱:HTC Korea TAEJIN Technology Co. 功能描述:5A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed) |
發(fā)布緊急采購，3分鐘左右您將得到回復。