- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377685 > LT1123CZ (LINEAR TECHNOLOGY CORP) Cap-Free, NMOS, 150mA Low Dropout Regulator with Reverse Current Protection PDF資料下載
參數(shù)資料
| 型號： | LT1123CZ |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 基準(zhǔn)電壓源/電流源 |
| 英文描述： | Cap-Free, NMOS, 150mA Low Dropout Regulator with Reverse Current Protection |
| 中文描述： | 5 V FIXED POSITIVE LDO REGULATOR, 0.75 V DROPOUT, PBCY3 |
| 封裝： | PLASTIC, TO-92, 3 PIN |
| 文件頁數(shù)： | 7/12頁 |
| 文件大?。?/td> | 241K |
| 代理商： | LT1123CZ |
7
LT1123
U
S
A
O
PPLICATI
IU
U
CURRENT LIMIT
For regulator circuits using the LT1123, current limiting is
achieved by limiting the base drive to the external PNP
pass transistor. This means that the actual system current
limit will be a function of both the current limit of the
LT1123 and the Beta of the external PNP. Beta-based
current limit schemes are normally not practical because
of uncertainties in the Beta of the pass transistor. Here the
drive characteristics of the LT1123 combined with the
Beta characteristics of the MJE1123 can provide reliable
Beta-based current limiting. This is shown in Figure 5
where the current limit of 30 randomly selected transistors
is plotted. The spread of current limit is reasonably well
controlled.
The curve in Figure 6 can be used to determine the range
of current limit of an LT1123 regulator circuit using an
MJE1123 as a pass transistor. The curve was generated
using the Beta versus I
C
curve of the MJE1123. The
minimum and maximum value curves are extrapolated
from the minimum and maximum Beta specifications.
THERMAL CONSIDERATIONS
The thermal characteristics of three components need to
be considered; the LT1123, the pass transistor, and R
D
.
Power dissipation should be calculated based on the worst
case conditions seen by each component during normal
operation.
The worst case power dissipation in the LT1123 is a
function of drive current, supply voltage, and the value of
R
D
. Worst case dissipation for the LT1123 occurs when
the drive current is equal to approximately one half of its
maximum value. Figure 7 plots the worst case power
dissipation in the LT1123 versus R
D
and V
IN
. The graph
was generated using the following formula:
=
(
>
P
V – V
4R
;R
10
D
BE
2
D
D
)
where V
BE
= the emitter/base voltage of the PNP pass
transistor (assumed to be 0.6V)
For some operating conditions R
D
may be replaced with a
short. This is possible in applications where the operating
Figure 7. Power in LT1123
V
IN
(V)
6
R
D
)
8
1k
LT1123 F07
10
100
7
15
14
13
12
11
10
9
5
0.4W
0.7W
0.1W
0.2W
0.3W
0.5W
Figure 6. MJE1123 I
C
vs I
B
Figure 5. Short Circuit Current for 30 Random Devices
OUTPUT CURRENT (A)
4.00
N
3
2
1
0
4
5
4.75
5.25
6.00
LT1123 F05
4.25 4.50
5.00
5.50 5.75
6
7
8
9
10
11
12
13
14
15
I
B
(A)
0
0
I
C
1
3
4
5
0.10
9
LT1123 F06
2
0.05
0.15
6
7
8
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT1123 | Cap-Free, NMOS, 150mA Low Dropout Regulator with Reverse Current Protection |
| LT1124 | Dual Low Noise, High Speed Precision Op Amps(雙路低噪聲,高速精密運算放大器) |
| LT1125 | Quad Low Noise, High Speed Precision Op Amps(四路低噪聲,高速精密運算放大器) |
| LT1125ACN | Dual/Quad Low Noise, High Speed Precision Op Amps |
| LT1124CJ8 | MODULE POWER 3.2VDC-6VDC 40A |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT1123CZ#PBF | 功能描述:IC REG CTRLR SGL 5V TO-92-3 RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性晶體管驅(qū)動器 系列:- 產(chǎn)品培訓(xùn)模塊:More Information on LDOs 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:正，固定式 輸出數(shù):2 輸出電壓:2.8V，3.3V 電流 - 電源:12mA 輸入電壓:5 V ~ 22 V 工作溫度:0°C ~ 70°C 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:16-SOIC 包裝:帶卷 (TR) |
| LT1123CZ#TR | 功能描述:IC REG CTRLR SGL 5V TO-92-3 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性晶體管驅(qū)動器 系列:- 產(chǎn)品培訓(xùn)模塊:More Information on LDOs 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:正，固定式 輸出數(shù):2 輸出電壓:2.8V，3.3V 電流 - 電源:12mA 輸入電壓:5 V ~ 22 V 工作溫度:0°C ~ 70°C 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:16-SOIC 包裝:帶卷 (TR) |
| LT1123CZ#TRPBF | 功能描述:IC REG CTRLR SGL 5V TO-92-3 RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性晶體管驅(qū)動器 系列:- 產(chǎn)品培訓(xùn)模塊:More Information on LDOs 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:正，固定式 輸出數(shù):2 輸出電壓:2.8V，3.3V 電流 - 電源:12mA 輸入電壓:5 V ~ 22 V 工作溫度:0°C ~ 70°C 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:16-SOIC 包裝:帶卷 (TR) |
| LT1123CZ2.85 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Interface IC |
| LT1124 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Dual/Quad Low Noise, High Speed Precision Op Amps |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。