Datasheet

LF411-N

SNOSBH6D –APRIL 1998–REVISED MARCH 2013

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Figure 27. Large Signal Inverting Figure 28. Large Signal Non-Inverting

Figure 29. Current Limit (R

=100Ω)

APPLICATION HINTS

The LF411 series of internally trimmed JFET input op amps (BI-FET II™ ) provide very low input offset voltage

and specified input offset voltage drift. These JFETs have large reverse breakdown voltages from gate to source

and drain eliminating the need for clamps across the inputs. Therefore, large differential input voltages can easily

be accommodated without a large increase in input current. The maximum differential input voltage is

independent of the supply voltages. However, neither of the input voltages should be allowed to exceed the

negative supply as this will cause large currents to flow which can result in a destroyed unit. BI-FET II™

Exceeding the negative common-mode limit on either input will force the output to a high state, potentially

causing a reversal of phase to the output. Exceeding the negative common-mode limit on both inputs will force

the amplifier output to a high state. In neither case does a latch occur since raising the input back within the

common-mode range again puts the input stage and thus the amplifier in a normal operating mode.

Exceeding the positive common-mode limit on a single input will not change the phase of the output; however, if

both inputs exceed the limit, the output of the amplifier may be forced to a high state.

The amplifier will operate with a common-mode input voltage equal to the positive supply; however, the gain

bandwidth and slew rate may be decreased in this condition. When the negative common-mode voltage swings

to within 3V of the negative supply, an increase in input offset voltage may occur.

Product Folder Links: LF411-N