參數(shù)資料
型號: LMC662CN
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 運算放大器
英文描述: CMOS Dual Operational Amplifier
中文描述: DUAL OP-AMP, 6300 uV OFFSET-MAX, 1.4 MHz BAND WIDTH, PDIP8
封裝: PLASTIC, DIP-8
文件頁數(shù): 8/13頁
文件大小: 430K
代理商: LMC662CN
Application Hints
(Continued)
The designer should be aware that when it is inappropriate
to lay out a PC board for the sake of just a few circuits, there
is another technique which is even better than a guard ring
on a PC board: Don’t insert the amplifier’s input pin into the
board at all, but bend it up in the air and use only air as an in-
sulator. Air is an excellent insulator. In this case you may
have to forego some of the advantages of PC board con-
struction, but the advantages are sometimes well worth the
effort of using point-to-point up-in-the-air wiring. See Figure
10
BIAS CURRENT TESTING
The test method of Figure 11is appropriate for bench-testing
bias current with reasonable accuracy. To understand its op-
eration, first close switch S2 momentarily. When S2 is
opened, then
A suitable capacitor for C2 would be a 5 pF or 10 pF silver
mica, NPO ceramic, or air-dielectric. When determining the
magnitude of I
, the leakage of the capacitor and socket
must be taken into account. Switch S2 should be left shorted
most of the time, or else the dielectric absorption of the ca-
pacitor C2 could cause errors.
Similarly, if S1 is shorted momentarily (while leaving S2
shorted)
where C
x
is the stray capacitance at the + input.
DS009763-20
FIGURE 9. Guard Ring Connections: Howland Current
Pump
DS009763-21
(Input pins are lifted out of PC board and soldered directly to components.
FIGURE 10. Air Wiring
DS009763-22
FIGURE 11. Simple Input Bias Current Test Circuit
www.national.com
8
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LMC662CN 制造商:Texas Instruments 功能描述:IC OP AMP DUAL CMOS DIP8 662
LMC662CN/NOPB 功能描述:運算放大器 - 運放 DUAL CMOS OP-AMP RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比(最小值):63 dB 輸入補償電壓:1 mV 輸入偏流(最大值):10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel
LMC662EM 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Texas Instruments 功能描述:
LMC662EN 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Texas Instruments 功能描述:
LMC6681 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Low Voltage, Rail-To-Rail Input and Output CMOS