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參數(shù)資料
| 型號： | L4945 |
| 廠商： | 意法半導體 |
| 元件分類： | 基準電壓源/電流源 |
| 英文描述： | Very Low Drop Voltage Regulators(低壓差5V穩(wěn)壓器) |
| 中文描述： | 非常低壓差電壓調節(jié)器（低壓差5V的穩(wěn)壓器） |
| 文件頁數(shù)： | 4/6頁 |
| 文件大小： | 42K |
| 代理商： | L4945 |
EXTERNAL COMPENSATION
Since the purpose of a voltageregulator is to sup-
ply and load variations, the open loop gain of the
regulators must be very high at low frequencies.
This may cause instability as a result of the vari-
ous poles present in the loop. To avoid this insta-
bility dominant pole compensation is used to re-
duce phase shift due to other poles at the unity
gain frequency. The lower the frequency of these
others poles at the unity gain frequency. The
lower the frequency of these other poles, the
greater must be capacitor esed to create the
dominant pole for the same DC gain.
Where the output transistor is a lateral PNP type
there is a pole in the regulation loop at a fre-
quencybtoo low to be compensated by a capaci-
tor which can be integrated. An external compen-
sation is thereforenecessary so a very high value
capacitor must be connected from the output to
ground.
The paeassitic equivalent series resistance of the
capacitor used adds a zero to the regulationloop.
This zero may compromise the stability of the
system since its effect tends to cancel the effect
of the pole added. In regulatorsthis ESR must be
less than 3
and the minimum capacitor value is
47
μ
F.
Figure 1:
Typical Dropout Voltage vs. T
j
(I
o
= 500mA).
L4945
4/6
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| L4946B | Quad Voltage Regulator with Inhibit and Reset(帶禁止和復位的四電壓穩(wěn)壓器) |
| L4946 | Quad Voltage Regulator with Inhibit and Reset(帶禁止和復位的四電壓穩(wěn)壓器) |
| L4947PD | 5V-0.5A Very Low Drop Regulator with Reset(帶復位低壓差穩(wěn)壓器) |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| L4946 | 制造商:STMicroelectronics 功能描述:REG LDO LIN FIX POS 10V/8V/5V/5V 0.125A/0.25A/0.2A/0.1A 11PI - Bulk |
| L4946B | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:QUAD VOLTAGE REGULATOR WITH INHIBIT AND RESET |
| L4946SQ | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Output Capacitor-Less Audio Subsystem with Programmable National 3D |
| L4947 | 功能描述:低壓差穩(wěn)壓器 - LDO 5.0 Volt 0.5 Amp 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 |
| L4947H | 功能描述:低壓差穩(wěn)壓器 - LDO 5.0V 0.5A Positive 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 |
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