LMC6041AIN National Semiconductor, LMC6041AIN Datasheet - Page 10

• Manufacturer Part Number: LMC6041AIN
• Description: IC OP AMP CMOS SINGL MICRO 8-DIP
• Manufacturer: National Semiconductor

Specifications of LMC6041AIN

• Amplifier Type: General Purpose
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 0.02 V/µs
• Gain Bandwidth Product: 75kHz
• Current - Input Bias: 0.002pA
• Voltage - Input Offset: 1000µV
• Current - Supply: 18µA
• Current - Output / Channel: 40mA
• Voltage - Supply, Single/dual (±): 4.5 V ~ 15.5 V, ±2.25 V ~ 7.75 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -
• Other names: *LMC6041AIN; *LMC6041AIN/NOPB; LMC6041AIN/NOPB

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Applications Hints
terminals of capacitors, diodes, conductors, resistors, relay
terminals, etc. connected to the op-amp’s inputs, as in Fig-
ure 4. To have a significant effect, guard rings should be
placed on both the top and bottom of the PC board. This PC
foil must then be connected to a voltage which is at the same
voltage as the amplifer inputs, since no leakage current can
flow between two points at the same potential. For example,
a PC board trace-to-pad resistance of 10
mally considered a very large resistance, could leak 5 pA if
the trace were a 5V bus adjacent to the pad of the input. This
would cause a 100 times degradation from the LMC6041’s
actual performance. However, if a guard ring is held within 5
mV of the inputs, then even a resistance of 10
cause only 0.05 pA of leakage current. See Figure 5 for
typical connections of guard rings for standard op-amp con-
figurations.
FIGURE 4. Example of Guard Ring
in P.C. Board Layout
(Continued)
12
Ω, which is nor-
11
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Ω would
10
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
insulator. 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
6.
(Input pins are lifted out of PC board and soldered directly to components.
All other pins connected to PC board.)
FIGURE 5. Typical Connections of Guard Rings
Non-Inverting Amplifier
FIGURE 6. Air Wiring
Inverting Amplifier
Follower
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