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參數(shù)資料
| 型號： | LM2936DTX-3.3 |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 基準電壓源/電流源 |
| 英文描述： | Ultra-Low Quiescent Current LDO Voltage Regulator |
| 中文描述： | 3.3 V FIXED POSITIVE LDO REGULATOR, 0.4 V DROPOUT, PSSO2 |
| 封裝： | TO-252, 3 PIN |
| 文件頁數(shù)： | 11/15頁 |
| 文件大?。?/td> | 861K |
| 代理商： | LM2936DTX-3.3 |
Applications Information
Unlike other PNP low dropout regulators, the LM2936 re-
mains fully operational to 40V. Owing to power dissipation
characteristics of the available packages, full output current
cannot be guaranteed for all combinations of ambient tem-
perature and input voltage. As an example, consider an
LM2936Z–5.0 operating at 25C ambient. Using the formula
for maximum allowable power dissipation given in (Note 3) ,
we find that P
= 641 mW at 25C. Including the small
contribution of the quiescent current to total power dissipa-
tion the maximum input voltage (while still delivering 50 mA
output current) is 17.3V. The LM2936Z–5.0 will go into ther-
mal shutdown if it attempts to deliver full output current with
an input voltage of more than 17.3V. Similarly, at 40V input
and 25C ambient the LM2936Z–5.0 can deliver 18 mA
maximum.
Under conditions of higher ambient temperatures, the volt-
age and current calculated in the previous examples will
drop. For instance, at the maximum ambient of 125C the
LM2936Z–5.0 can only dissipate 128 mW, limiting the input
voltage to 7.34V for a 50 mA load, or 3.5 mA output current
for a 40V input.
The junction to ambient thermal resistance
θ
rating has
two distinct components: the junction to case thermal resis-
tance rating
θ
; and the case to ambient thermal resistance
rating
θ
CA
. The relationship is defined as:
θ
JA
=
θ
JC
+
θ
CA
.
For the SO-8 and TO-252 surface mount packages the
θ
rating can be improved by using the copper mounting pads
on the printed circuit board as a thermal conductive path to
extract heat from the package.
On the SO-8 package the four ground pins are thermally
connected to the backside of the die. Adding approximately
0.04 square inches of 2 oz. copper pad area to these four
pins will improve the
θ
rating to approximately 110C/W. If
this extra pad are is placed directly beneath the package
there should not be any impact on board density.
On the TO-252 package the ground tab is thermally con-
nected to the backside of the die. Adding 1 square inch of 2
oz. copper pad area directly under the ground tab will im-
prove the
θ
JA
rating to approximately 50C/W.
While the LM2936 has an internally set thermal shutdown
point of typically 160C, this is intended as a safety feature
only. Continuous operation near the thermal shutdown tem-
perature should be avoided as it may have a negative affect
on the life of the device.
While the LM2936 maintains regulation to 60V, it will not
withstand a short circuit above 40V because of safe operat-
ing area limitations in the internal PNP pass device. Above
60V the LM2936 will break down with catastrophic effects on
the regulator and possibly the load as well. Do not use this
device in a design where the input operating voltage may
exceed 40V, or where transients are likely to exceed 60V.
SHUTDOWN PIN
The LM2936BM has a pin for shutting down the regulator
output.Applying a Logic Level High (
>
2.0V) to the Shutdown
pin will cause the output to turn off. Leaving the Shutdown
pin open, connecting it to Ground, or applying a Logic Level
Low (
<
0.6V) will allow the regulator output to turn on.
L
www.national.com
11
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| LM2936HVBMAX3.0 | Ultra-Low Quiescent Current LDO Voltage Regulator |
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相關代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM2936DTX-5.0 | 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 |
| LM2936DTX-5.0/NOPB | 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 |
| LM2936HVBMA-3.0 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Texas Instruments 功能描述:IC V REG LDO LOW IQ 3V SMD SOIC8 |
| LM2936HVBMA-3.0/NOPB | 功能描述:IC REG LDO 3V 50MA 8SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - 線性 系列:- 標準包裝:1 系列:- 穩(wěn)壓器拓撲結(jié)構(gòu):正，固定式 輸出電壓:4V 輸入電壓:最高 16V 電壓 - 壓降（標準）:0.28V @ 150mA 穩(wěn)壓器數(shù)量:1 電流 - 輸出:150mA 電流 - 限制（最小）:- 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:5-VFBGA 供應商設備封裝:5-uSMD 包裝:Digi-Reel® 其它名稱:LP2985AIBP-4.0DKR |
| LM2936HVBMA-3.3 | 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 |
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