參數(shù)資料
型號(hào): LM34CAZ
廠商: National Semiconductor Corporation
元件分類: 溫度/濕度傳感器
英文描述: Precision Fahrenheit Temperature Sensors
中文描述: 精密華氏溫度傳感器
文件頁(yè)數(shù): 6/12頁(yè)
文件大?。?/td> 248K
代理商: LM34CAZ
Typical Performance Characteristics
(Continued)
Typical Applications
The LM34 can be applied easily in the same way as other
integrated-circuit temperature sensors. It can be glued or ce-
mented to a surface and its temperature will be within about
0.02F of the surface temperature. This presumes that the
ambient air temperature is almost the same as the surface
temperature; if the air temperature were much higher or
lower than the surface temperature, the actual temperature
of the LM34 die would be at an intermediate temperature be-
tween the surface temperature and the air temperature. This
is expecially true for the TO-92 plastic package, where the
copper leads are the principal thermal path to carry heat into
the device, so its temperature might be closer to the air tem-
perature than to the surface temperature.
To minimize this problem, be sure that the wiring to the
LM34, as it leaves the device, is held at the same tempera-
ture as the surface of interest. The easiest way to do this is
to cover up these wires with a bead of epoxy which will in-
sure that the leads and wires are all at the same temperature
as the surface, and that the LM34 die’s temperature will not
be affected by the air temperature.
The TO-46 metal package can also be soldered to a metal
surface or pipe without damage. Of course in that case, the
V
terminal of the circuit will be grounded to that metal. Alter-
natively, the LM34 can be mounted inside a sealed-end
metal tube, and can then be dipped into a bath or screwed
into a threaded hole in a tank. As with any IC, the LM34 and
accompanying wiring and circuits must be kept insulated and
dry, to avoid leakage and corrosion. This is especially true if
the circuit may operate at cold temperatures where conden-
sation can occur. Printed-circuit coatings and varnishes such
as Humiseal and epoxy paints or dips are often used to in-
sure that moisture cannot corrode the LM34 or its connec-
tions.
These
light-weight heat fin to decrease the thermal time constant
devices
are
sometimes
soldered
to
a
small,
and speed up the response in slowly-moving air. On the
other hand, a small thermal mass may be added to the sen-
sor to give the steadiest reading despite small deviations in
the air temperature.
Capacitive Loads
Like most micropower circuits, the LM34 has a limited ability
to drive heavy capacitive loads. The LM34 by itself is able to
drive 50 pF without special precautions. If heavier loads are
anticipated, it is easy to isolate or decouple the load with a
resistor; see Figure 3 Or you can improve the tolerance of
capacitance with a series R-C damper from output to
ground; see Figure 4 When the LM34 is applied with a 499
load resistor (as shown), it is relatively immune to wiring ca-
pacitance because the capacitance forms a bypass from
ground to input, not on the output. However, as with any lin-
ear circuit connected to wires in a hostile environment, its
performance can be affected adversely by intense electro-
magnetic sources such as relays, radio transmitters, motors
with arcing brushes, SCR’s transients, etc., as its wiring can
act as a receiving antenna and its internal junctions can act
as rectifiers. For best results in such cases, a bypass capaci-
tor from V
to ground and a series R-C damper such as 75
in series with 0.2 or 1 μF from output to ground are often
useful. These are shown in the following circuits.
Noise Voltage
DS006685-31
Start-Up Response
DS006685-32
DS006685-6
www.national.com
6
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參數(shù)描述
LM34CAZ 制造商:Texas Instruments 功能描述:IC PRECISION TEMP SENSOR TO-92-3
LM34CAZ/NOPB 功能描述:板上安裝溫度傳感器 PREC FAHRENHEIT TEMP SENSOR RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor
LM34CAZ/T4 制造商:Texas Instruments 功能描述:Temp Sensor Analog Serial (2-Wire) 3-Pin TO-92 制造商:Texas Instruments 功能描述:Temp Sensor Analog(Voltage) Serial (2-Wire) 3-Pin TO-92
LM34CH 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Precision Fahrenheit Temperature Sensors
LM34CH/NOPB 功能描述:IC SENSOR TEMP PREC FAHR TO46-3 RoHS:是 類別:傳感器,轉(zhuǎn)換器 >> 溫度 系列:- 其它有關(guān)文件:DS1820 Digital Thermometer 標(biāo)準(zhǔn)包裝:500 系列:- 感應(yīng)溫度:-55°C ~ 125°C 輸出類型:開(kāi)路漏極 電源電壓:3 V ~ 5.5 V 精確度:±0.5°C 封裝/外殼:TO-226-3、TO-92-3 標(biāo)準(zhǔn)主體 供應(yīng)商設(shè)備封裝:TO-92 包裝:散裝