LT1462 Linear Technology, LT1462 Datasheet - Page 7

• Manufacturer Part Number: LT1462
• Description: Dual/Quad Micropower/ 260uW C-Load Picoampere Bias Current JFET Input Op Amps
• Manufacturer: Linear Technology

APPLICATIONS
Phase Reversal Protection
Most industry standard JFET input single, dual and quad
op amps exhibit phase reversal at the output when the
negative common mode limit at the input is exceeded.
Common mode range is at a premium at 5V supplies. The
Figures show a 5.2V sine wave input (Figure 1a), the
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Figure 1. Voltage Follower with Input Exceeding the Common Mode Range (V
INFORMATION
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(1a) 5.2V Sine Wave
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(1c) LT1462/LT1463 Output
with 5V Supplies
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LT1462 • F01a
response of a competing JFET input op amp in the unity-
gain follower mode (Figure 1b) and the response of the
LT1462/LT1463 (Figure 1c).
The phase reversal of Figure 1b can cause lock-up in servo
systems. The LT1462/LT1463 does not phase-reverse when
the common mode input is anywhere within the supplies.
(1b) Typical JFET Input Op Amp
with 5V Supplies
LT1462 • F01c
S
LT1462 • F01b
= 5V)
LT1462/LT1463
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