LT1462/LT1463
Dual/Quad Micropower,
260µW C-Load Picoampere
Bias Current JFET Input Op Amps
FEATURES
s Input Bias Current:
2pA Max (LT1462A)
20pA Max (LT1462, LT1463)
s Supply Current per Amplifier: 45µA Max
s Unity-Gain Stable for C-LoadTM Up to 10nF
s Input Common Mode Range Includes Positive Rail
s Guaranteed Specs with ±5V, ±15V Supplies
s Gain Bandwidth Product: 175kHz Typ
s Slew Rate: 0.13V/µs Typ
s Guaranteed Matching Specifications
s Standard Pinout: SO-8, SO-14 Package
U
APPLICATIONS
s Battery-Powered Systems
s Photocurrent Amplifiers
s Low Frequency, Micropower Active Filters
s Low Droop Track-and-Hold Circuits
DESCRIPTION
The LT ®1462 (dual) and LT1463 (quad) are the first
micropower op amps (45µA max per amp) to offer
picoampere input bias currents (1pA typ) and unity gain
stability for capacitive loads up to 10nF. The output can
swing a 10k load to within 1.5V of either supply, just like
op amps that require an order of magnitude more supply
current. This unique combination of performance makes
the LT1462/LT1463 ideal over a wide range of input and
output impedances.
In the design and testing of the LT1462/LT1463, particular
emphasis has been placed on optimizing performance in
the low cost SO-8 (dual) and 14-lead SO package (quad) for
±15V and ±5V supplies. The input common mode range
includes the positive rail. Slew rate (0.08V/µs min) and gain
bandwidth product (125kHz min) are 100% tested. A full set
of matching specifications is also provided.
, LTC and LT are registered trademarks of Linear Technology Corporation.
C-Load is a trademark of Linear Technology Corporation.
TYPICAL APPLICATION
Low Power Logging Amplifier
R8
100k
D1
1N4148
Q1
2N3904
C1
1nF
R5
24k
R1
100Ω
5V
2– 4
1/4 LT1463
3+
11
– 5V
PHOTODIODE
R2
24k
C2
200pF
C5
200pF
1
12 +
1/4 LT1463
13 –
R4
10M
14
D2
1N4148
R3
100k
C5
1µF R9
1M
DC
5+
OUT C3
0.47µF
AMP 3
7
1/4 LT1463
6–
R7 R10
10M 50k
D3
1N4148
R6
100k
INPUT
DC OUTPUT
CURRENT VOLTAGE OF AMP 3
10pA
100pA
1nA
10nA
100nA
1 µA
10 µA
100 µA
1mA
–0.145V
–0.341V
–0.518V
–0.684V
–0.846V
–0.995V
–1.13V
–1.25V
–1.37V
10 +
1/4 LT1463
9–
C4
10µF
8
R11
1M
AC
OUT
R3
10k
R12
10k
1462 • TA01
Small-Signal Response, CL = 10nF
AV = 1
VS = ±5V, ±15V
CL = 10nF
1462 • TA02
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