Datasheet

6
LT1457
TYPICAL PERFORMANCE CHARACTERISTICS
U
W
Small-Signal Response
A
V
= 1, C
L
= 10,000pF
APPLICATIONS INFORMATION
WUU
U
LT1457 TPC20LT1457 TPC19 LT1457 TPC21
Large-Signal Response
A
V
= 1, C
L
= 100pF
Small-Signal Response
A
V
= 1, C
L
= 1000pF
Phase Reversal Protection
Most industry standard JFET input single, dual, and quad
op amps (e.g., LF156, LF351, LF353, LF411, LF412,
OP-15, OP-16, OP-215, and TL084) exhibit phase reversal
at the output when the negative common-mode limit at the
input is exceeded (i.e., below –12V with ±15V supplies).
The photos show a ±16V sine wave input (A), the response
of an LF412A in the unity gain follower mode (B), and the
response of the LT1457 (C).
The phase reversal of photo (B) can cause lock-up in servo
systems. The LT1457 does not phase-reverse due to a
unique phase reversal protection circuit.
All Photos 5V/Div Vertical Scale, 50µs/Div Horizontal Scale
(B) LF412A Output(A) ±16V Sine Wave Input (C) LT1457 Output
LT1457 AI03LT1457 AI01 LT1457 AI02