- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377795 > LX8415-00CSTT (MICROSEMI CORP-ANALOG MIXED SIGNAL GROUP) Positive Adjustable Voltage Regulator PDF資料下載
參數(shù)資料
| 型號(hào)： | LX8415-00CSTT |
| 廠商： | MICROSEMI CORP-ANALOG MIXED SIGNAL GROUP |
| 元件分類： | 基準(zhǔn)電壓源/電流源 |
| 英文描述： | Positive Adjustable Voltage Regulator |
| 中文描述： | ADJUSTABLE POSITIVE LDO REGULATOR, 1.3 V DROPOUT, PDSO4 |
| 封裝： | PLASTIC, SOT-223, 4 PIN |
| 文件頁(yè)數(shù)： | 5/7頁(yè) |
| 文件大小： | 191K |
| 代理商： | LX8415-00CSTT |
0.5A L
O W
D
ROPOUT
P
OSITIVE
R
EGULATORS
LX8415-xx
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
5
Copyright 1999
Rev. 0.4 1/99
P
R E L I M I N A R Y
D
A T A
S
H E E T
A P P L I C AT I O N N O T E S
FIGURE 2
— BASIC ADJUSTABLE REGULATOR
R2+R1
R1
LX8415-xx
OUT
IN
ADJ
V
OUT
V
IN
R1
R2
V
REF
I
50μA
V
OUT
= V
REF
1 + R2
ADJ
R2
R1
OUTPUT VOLTAGE
The LX8
415
ICs develop a 1.25V reference voltage between the output
and the adjust terminal (See Figure 2). By placing a resistor, R1,
between these two terminals, a constant current is caused to flow
through R1 and down through R2 to set the overall output voltage.
Normally this current is the specified minimum load current of 10mA.
Because I
is very small and constant when compared with the current
through R1, it represents a small error and can usually be ignored.
LX8415-xx
OUT
IN
ADJ
V
IN
R1
R2
R
L
R
Parasitic
Line Resistance
Connect
R1 to Case
of Regulator
Connect
R2
to Load
FIGURE 3
— CONNECTIONS FOR BEST LOAD REGULATION
LOAD REGULATION
Because the LX8
415
regulators are three-terminal devices, it is not
possible to provide true remote load sensing. Load regulation will
be limited by the resistance of the wire connecting the regulator to
the load. The data sheet specification for load regulation is
measured at the bottom of the package. Negative side sensing is a
true Kelvin connection, with the bottom of the output divider
returned to the negative side of the load. Although it may not be
immediately obvious, best load regulation is obtained when the top
of the resistor divider, (R1), is connected
directly
to the case of the
regulator,
not to the load
. This is illustrated in Figure 3. If R1 were
connected to the load, the effective resistance between the regulator
and the load would be:
R
Peff
= R
P
*
where: R
P
≡
Actual parasitic line resistance.
When the circuit is connected as shown in Figure 3, the parasitic
resistance appears as its actual value, rather than the higher R
.
Even when the circuit is optimally configured, parasitic resistance
can be a significant source of error. A 100 mil (2.54 mm) wide PC
trace built from 1 oz. copper-clad circuit board material has a
parasitic resistance of about 5 milliohms per inch of its length at
room temperature. If a 3-terminal regulator used to supply 2.50 volts
is connected by 2 inches of this trace to a load which draws 5 amps
of current, a 50 millivolt drop will appear between the regulator and
the load. Even when the regulator output voltage is precisely
2.50 volts, the load will only see 2.45 volts, which is a 2% error. It
LOAD REGULATION
(continued)
is important to keep the connection between the regulator output
pin and the load as short as possible, and to use wide traces or
heavy-gauge wire.
The minimum specified output capacitance for the regulator
should be located near the reglator package. If several capacitors
are used in parallel to construct the power system output capaci-
tance, any capacitors beyond the minimum needed to meet the
specified requirements of the regulator should be located near the
sections of the load that require rapidly-changing amounts of
current. Placing capacitors near the sources of load transients will
help ensure that power system transient response is not impaired
by the effects of trace impedance.
To maintain good load regulation, wide traces should be used on
the input side of the regulator, especially between the input
capacitors and the regulator. Input capacitor ESR must be small
enough that the voltage at the input pin does not drop below V
IN (MIN)
during transients.
V
IN (MIN)
= V
OUT
+ V
DROPOUT (MAX)
where: V
IN (MIN)
≡
the lowest allowable instantaneous
voltage at the input pin.
≡
the designed output voltage for the
power supply system.
V
DROPOUT (MAX)
≡
the specified dropout voltage
for the installed regulator.
V
OUT
THERMAL CONSIDERATIONS
The LX8
415
regulators have internal power and thermal limiting
circuitry designed to protect each device under overload conditions.
For continuous normal load conditions, however, maximum junc-
tion temperature ratings must not be exceeded. It is important to
give careful consideration to all sources of thermal resistance from
junction to ambient. This includes junction to case, case to heat sink
interface, and heat sink thermal resistance itself.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LX8415-25CSTT | THREE-TERMINAL POSITIVE FIXED VOLTAGE REGULATORS |
| LX8415-33CSTT | THREE-TERMINAL POSITIVE FIXED VOLTAGE REGULATORS |
| LX8554-XX | 5A EXTREMELY LOW DROPOUT POSITIVE REGULATORS |
| LX8554-00CDD | 5A EXTREMELY LOW DROPOUT POSITIVE REGULATORS |
| LX8554-00CP | 5A EXTREMELY LOW DROPOUT POSITIVE REGULATORS |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LX8415-25 | 制造商:MICROSEMI 制造商全稱:Microsemi Corporation 功能描述:0.5 A LOW DROPOUT POSITIVE REGULATORS |
| LX8415-25CST | 功能描述:IC REG LDO 2.5V SOT-223 RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式和可調(diào)式 輸出電壓:3.3V，1.25 V ~ 5.7 V 輸入電壓:4.5 V ~ 7 V 電壓 - 壓降（標(biāo)準(zhǔn)）:1.1V @ 1A 穩(wěn)壓器數(shù)量:2 電流 - 輸出:1A 電流 - 限制（最小）:1A 工作溫度:0°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:TO-252-5，DPak（4 引線 + 接片），TO-252AD 供應(yīng)商設(shè)備封裝:PPAK 包裝:管件 其它名稱:497-3576-5 |
| LX8415-25CSTT | 制造商:MICROSEMI 制造商全稱:Microsemi Corporation 功能描述:Positive Fixed Voltage Regulator |
| LX8415-33 | 制造商:MICROSEMI 制造商全稱:Microsemi Corporation 功能描述:0.5 A LOW DROPOUT POSITIVE REGULATORS |
| LX8415-33CST | 功能描述:IC REG LDO 3.3V SOT-223 RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):正，固定式和可調(diào)式 輸出電壓:3.3V，1.25 V ~ 5.7 V 輸入電壓:4.5 V ~ 7 V 電壓 - 壓降（標(biāo)準(zhǔn)）:1.1V @ 1A 穩(wěn)壓器數(shù)量:2 電流 - 輸出:1A 電流 - 限制（最?。?1A 工作溫度:0°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:TO-252-5，DPak（4 引線 + 接片），TO-252AD 供應(yīng)商設(shè)備封裝:PPAK 包裝:管件 其它名稱:497-3576-5 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。