參數(shù)資料
型號: LT1121IST-5
廠商: LINEAR TECHNOLOGY CORP
元件分類: 基準(zhǔn)電壓源/電流源
英文描述: Octal Buffers/Drivers With 3-State Outputs 20-SO 0 to 70
中文描述: 5 V FIXED POSITIVE LDO REGULATOR, 0.7 V DROPOUT, PDSO4
封裝: PLASTIC, SOT-223, 3 PIN
文件頁數(shù): 10/12頁
文件大?。?/td> 269K
代理商: LT1121IST-5
10
LT1121/LT1121-3.3/LT1121-5
U
S
A
that the ESR of the capacitor is low (ceramic) the sug-
gested series resistor is shown in Table 5. The LT1121 is
a micropower device and output transient response will be
a function of output capacitance. See the Transient Re-
sponse curves in the Typical Performance Characteristics.
Larger values of output capacitance will decrease the peak
deviations and provide improved output transient re-
sponse. Bypass capacitors, used to decouple individual
components powered by the LT1121, will increase the
effective value of the output capacitor.
O
PPLICATI
U
U
Table 5.
SUGGESTED SERIES
RESISTOR
2
1
1
None Needed
OUTPUT CAPACITANCE
0.33
μ
F
0.47
μ
F
0.68
μ
F
>1
μ
F
Protection Features
The LT1121 incorporates several protection features which
make it ideal for use in battery-powered circuits. In addi-
tion to the normal protection features associated with
monolithic regulators, such as current limiting and ther-
mal limiting, the device is protected against reverse input
voltages, reverse output voltages, and reverse voltages
from output to input.
Current limit protection and thermal overload protection
are intended to protect the device against current overload
conditions at the output of the device. For normal opera-
tion, the junction temperature should not exceed 125
°
C.
The input of the device will withstand reverse voltages of
30V. Current flow into the device will be limited to less than
1mA (typically less than 100
μ
A) and no negative voltage
will appear at the output. The device will protect both itself
and the load. This provides protection against batteries
that can be plugged in backwards.
For fixed voltage versions of the device, the output can be
pulled below ground without damaging the device. If the
input is open circuit or grounded the output can be pulled
below ground by 20V. The output will act like an open
circuit, no current will flow out of the pin. If the input is
powered by a voltage source, the output will source the
short-circuit current of the device and will protect itself by
thermal limiting. For the adjustable version of the device,
the output pin is internally clamped at one diode drop
below ground. Reverse current for the adjustable device
must be limited to 5mA.
In circuits where a backup battery is required, several
different input/output conditions can occur. The output
voltage may be held up while the input is either pulled to
ground, pulled to some intermediate voltage, or is left
open circuit. Current flow back into the output will vary
depending on the conditions. Many battery-powered cir-
cuits incorporate some form of power management. The
following information will help optimize battery life. Table
6 summarizes the following information.
The reverse output current will follow the curve in Figure
2 when the input pin is pulled to ground. This current flows
through the output pin to ground. The state of the shut-
down pin will have no effect on output current when the
input pin is pulled to ground.
In some applications it may be necessary to leave the input
to the LT1121 unconnected when the output is held high.
This can happen when the LT1121 is powered from a
rectified AC source. If the AC source is removed, then the
input of the LT1121 is effectively left floating. The reverse
output current also follows the curve in Figure 2 if the input
pin is left open. The state of the shutdown pin will have no
effect on the reverse output current when the input pin is
floating.
OUTPUT VOLTAGE (V)
0
O
μ
A
100
90
80
70
60
50
40
30
20
10
0
8
1121 F02
2
4
6
10
1
3
5
7
9
T
J
= 25°C
V
< V
CURRENT FLOWS
INTO OUTPUT PIN
TO GROUND
LT1121-3.3
LT1121
(V
OUT
= V
ADJ
)
LT1121-5
Figure 2. Reverse Output Current
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LT1121IST-5#PBF 功能描述:IC REG LDO 5V .15A SOT223-3 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:8V 輸入電壓:10.5 V ~ 23 V 電壓 - 壓降(標(biāo)準(zhǔn)):1.7V @ 40mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:100mA(最小值) 電流 - 限制(最?。?- 工作溫度:0°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 供應(yīng)商設(shè)備封裝:8-SOIC 包裝:剪切帶 (CT) 產(chǎn)品目錄頁面:1075 (CN2011-ZH PDF) 其它名稱:296-24390-1
LT1121IST-5#TR 功能描述:IC REG LDO 5V .15A SOT223-3 RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 產(chǎn)品培訓(xùn)模塊:More Information on LDOs 標(biāo)準(zhǔn)包裝:50 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:3.3V 輸入電壓:最高 15V 電壓 - 壓降(標(biāo)準(zhǔn)):1.1V @ 800mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:800mA 電流 - 限制(最小):800mA 工作溫度:0°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:TO-263-4,D²Pak(3 引線+接片),TO-263AA 供應(yīng)商設(shè)備封裝:D2PAK-3 包裝:管件
LT1121IST-5#TRPBF 功能描述:IC REG LDO 5V .15A SOT223-3 RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 產(chǎn)品培訓(xùn)模塊:More Information on LDOs 標(biāo)準(zhǔn)包裝:50 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正,固定式 輸出電壓:3.3V 輸入電壓:最高 15V 電壓 - 壓降(標(biāo)準(zhǔn)):1.1V @ 800mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:800mA 電流 - 限制(最小):800mA 工作溫度:0°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:TO-263-4,D²Pak(3 引線+接片),TO-263AA 供應(yīng)商設(shè)備封裝:D2PAK-3 包裝:管件
LT1121IST-5PBF 制造商:Linear Technology 功能描述:LT1121IST-5PBF
LT1121IST5TR 制造商:LT 功能描述:New