Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsLinear ICsLinear IC - Op-amp Multi-purpose SO 8

LT1462/LT1463

Dual/Quad Micropower,

260µW C-Load Picoampere

Bias Current JFET Input Op Amps

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Input Bias Current:

2pA Max (LT1462A)

20pA Max (LT1462, LT1463)

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Supply Current per Amplifier: 45

A Max

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Unity-Gain Stable for C-Load

Up to 10nF

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Input Common Mode Range Includes Positive Rail

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Guaranteed Specs with ±5V, ±15V Supplies

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Gain Bandwidth Product: 175kHz Typ

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Slew Rate: 0.13V/µs Typ

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Guaranteed Matching Specifications

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Standard Pinout: SO-8, SO-14 Package

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.

FEATURES

DESCRIPTION

TYPICAL APPLICATION

, LTC and LT are registered trademarks of Linear Technology Corporation.

–

R3

10k

C4

10µF

R11

1/4 LT1463

R12

10k

R10

50k

R6

100k

D3

1N4148

R7

10M

R5

24k

C5

200pF

AMP 3

1/4 LT1463

DC

OUT

C3

0.47µF

R3

100k

D2

1N4148

R4

10M

1/4 LT1463

C2

200pF

R2

24k

–5V

R1

100Ω

PHOTODIODE

C1

1nF

D1

1N4148

R8

100k

Q1

2N3904

C5

1µF

R9

1462 • TA01

AC

OUT

 INPUT DC OUTPUT

 CURRENT VOLTAGE OF AMP 3 

 10pA –0.145V

 100pA –0.341V

 1nA –0.518V

 10nA –0.684V

 100nA –0.846V

1µA –0.995V

10µA –1.13V

 100 µA –1.25V

 1mA –1.37V

Low Power Logging Amplifier

= 1

= ±5V, ±15V

= 10nF

1462 • TA02

C-Load is a trademark of Linear Technology Corporation.

Small-Signal Response, C

= 10nF

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Battery-Powered Systems

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Photocurrent Amplifiers

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Low Frequency, Micropower Active Filters

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Low Droop Track-and-Hold Circuits

APPLICATIONS

Summary of content (12 pages)

PAGE 1
LT1462/LT1463 Dual/Quad Micropower, 260µW C-Load Picoampere Bias Current JFET Input Op Amps U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ 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.
PAGE 2
LT1462/LT1463 W W U W ABSOLUTE MAXIMUM RATINGS Supply Voltage ..................................................... ±20V Differential Input Voltage ....................................... ±40V Input Current ....................................................... 20mA Output Short-Circuit Duration ......................... Indefinite Operating Temperature Range ............... – 40°C to 85°C Specified Temperature Range ................ – 40°C to 85°C Maximum Junction Temperature ........................
PAGE 3
LT1462/LT1463 ELECTRICAL CHARACTERISTICS VS = ±15V, VCM = 0V, TA = 25°C, unless otherwise noted. SYMBOL PARAMETER CONDITIONS (Note 1) VOUT Output Voltage Swing RL = 10k RL = 2k VS = ±5V, RL = 2k IO Output Current SR Slew Rate GBW Gain Bandwidth Product IS Supply Current per Amplifier MIN LT1462AC TYP MAX LT1462C/LT1463C MIN TYP MAX UNITS ±13.5 ±11.0 ±3.5 ±13.7 ±12.4 ±3.7 ±13.5 ±11.0 ±3.5 ±13.7 ±12.4 ±3.7 ±13 ±17 ±13 ±17 mA RL = 10k (Note 4) 0.08 0.13 0.08 0.
PAGE 4
LT1462/LT1463 ELECTRICAL CHARACTERISTICS VS = ±15V, VCM = 0V, 0°C ≤ TA ≤ 70°C, unless otherwise noted. MIN LT1462AC TYP MAX LT1462C/LT1463C MIN TYP MAX SYMBOL PARAMETER CONDITIONS (Note 1) UNITS ∆CMRR Common Mode Rejection Match (Notes 5, 7) ● 73 84 70 84 dB ∆PSRR Power Supply Rejection Match (Notes 5, 7) ● 77 87 74 87 dB VS = ±15V, VCM = 0V, – 40°C ≤ TA ≤ 85°C (Note 2), unless otherwise noted.
PAGE 5
LT1462/LT1463 U W TYPICAL PERFORMANCE CHARACTERISTICS Input Bias and Offset Current vs Temperature 20 VS = ±15V VCM = 0V LT1462/LT1463 LT1462A 100 BIAS CURRENT 10 15 15 COMMON MODE RANGE (V) 1000 16 VS = ±15V TA = 25°C INPUT BIAS CURRENT (pA) 10 5 0 OFFSET CURRENT 1 0 25 75 100 50 AMBIENT TEMPERATURE (°C) –5 –15 125 10 –5 0 5 –10 COMMON MODE INPUT VOLTAGE (V) 13 12 –11 –12 –13 Supply Current vs Temperature 50 40 VS = ±15V VS = ±5V 20 100 1/f CORNER = 5Hz 30 0.
PAGE 6
LT1462/LT1463 U W TYPICAL PERFORMANCE CHARACTERISTICS 100 80 PHASE 40 60 30 40 20 20 GAIN 10 0 0 PHASE MARGIN (DEG) 50 –20 –10 1 VS = ±15V TA = 25°C 80 60 40 20 –40 1000 10 100 FREQUENCY (kHz) 120 100 POSITIVE SUPPLY 80 NEGATIVE SUPPLY 60 40 20 0 10 100 10k 1k FREQUENCY (Hz) 100k 10 1M 100 95 VS = ±15V TA = 25°C Closed-Loop Output Impedance 10k VS = ±2.
PAGE 7
LT1462/LT1463 U W U U APPLICATIONS INFORMATION 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 response of a competing JFET input op amp in the unitygain follower mode (Figure 1b) and the response of the LT1462/LT1463 (Figure 1c).
PAGE 8
LT1462/LT1463 U TYPICAL APPLICATIONS 10Hz 4th Order Chebyshev Lowpass Filter (0.01dB Ripple) R2 237k R5 154k C1 33nF R1 237k C3 10nF 15V R3 249k 2 VIN C2 100nF – 4 1/4 LT1463 3 R6 249k R4 154k 1 13 + 1/4 LT1463 C4 330nF 11 – 12 14 + VOUT LT1462 • TA05 –15V TYPICAL OFFSET ≈ 0.6mV 1% TOLERANCES FOR VIN = 10VP-P,V OUT = –110dB AT f > 300Hz V OUT = –6dB AT f = 16Hz THE LOW INPUT BIAS CURRENTS ALLOW THE USE OF HIGH RESISTOR VALUES Micropower 0.
PAGE 9
LT1462/LT1463 W W SI PLIFIED SCHE ATIC VCC R20 R6 R3 R4 Q3 ×4 Q4 R7 Q5 J4 J3 R5 Q17 Q7 R17 – IN Q18 Q20 J5 R22 C2 R10 Q16 +IN Q22 R18 OUT J1 J2 VCC VCC Q21 C1 Q15 Q28 VEE Q25 Q13 Q14 Q1 Q8 R5 Q23 R16 Q11 1µA R1 R19 R1O Q29 Q2 Q9 R2 R5 Q19 Q24 VEE Q10 Q26 Q27 R10 1462 SS VEE 9
PAGE 10
LT1462/LT1463 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.300 – 0.325 (7.620 – 8.255) 0.065 (1.651) TYP 0.009 – 0.015 (0.229 – 0.381) ( +0.635 –0.381 0.125 (3.175) MIN 0.005 (0.127) MIN +0.025 0.325 –0.015 8.255 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) ) 0.018 ± 0.003 (0.457 ± 0.076) 0.100 ± 0.010 (2.
PAGE 11
LT1462/LT1463 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N Package 14-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.770* (19.558) MAX 14 13 12 11 10 9 8 1 2 3 4 5 6 7 0.255 ± 0.015* (6.477 ± 0.381) 0.130 ± 0.005 (3.302 ± 0.127) 0.300 – 0.325 (7.620 – 8.255) 0.045 – 0.065 (1.143 – 1.651) 0.015 (0.380) MIN 0.065 (1.651) TYP 0.009 – 0.015 (0.229 – 0.381) +0.025 0.325 –0.015 0.005 (0.125) MIN 0.100 ± 0.010 (2.540 ± 0.
PAGE 12
LT1462/LT1463 U TYPICAL APPLICATION Micropower 0.016% Voltage-to-Frequency Converter LT1009 VREF = – 2.5V R3 1k –5V C4 1µF 17 1/2 LTC1043 5V 8 7 fOUT: 0kHz TO 3kHz 11 14 13 fOUT = RIN 12 4 VIN 0V TO 5V 6.19k GAIN 2.5k 5V 6 C1 1µF – 5 + 4 –5V R1 100k )( ) VIN 1 (RIN)(CIN) VREF 16 CIN 0.