Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

LMC660 Datasheet(PDF) 8 Page - National Semiconductor (TI)

[Old version datasheet] Texas Instruments acquired National semiconductor.
Part No. LMC660
Description  CMOS Quad Operational Amplifier
Download  12 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  NSC [National Semiconductor (TI)]
Homepage  http://www.national.com
Logo 

LMC660 Datasheet(HTML) 8 Page - National Semiconductor (TI)

 
Zoom Inzoom in Zoom Outzoom out
 8 / 12 page
background image
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
7.
BIAS CURRENT TESTING
The test method of
Figure 8 is 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 bea5pFor10pF silver
mica, NPO ceramic, or air-dielectric. When determining the
magnitude of I
b−, 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.
DS008767-17
(a) Inverting Amplifier
DS008767-18
(b) Non-Inverting Amplifier
DS008767-19
(c) Follower
DS008767-20
(d) Howland Current Pump
FIGURE 6. Guard Ring Connections
DS008767-21
(Input pins are lifted out of PC board and soldered directly to components.
All other pins connected to PC board.)
FIGURE 7. Air Wiring
DS008767-22
FIGURE 8. Simple Input Bias Current Test Circuit
www.national.com
8


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12 


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn