Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsLinear ICsLinear IC - Op-amp J-FET SO 8

LT1457

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Handles 10,000pF Capacitive Load

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450µV Max Offset Voltage

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1200µV Max Offset Voltage in S8 Package

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50pA Bias Current at 70°C

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13nV/√Hz Voltage Noise

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4V/µs Slew Rate

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4µV/°C Drift

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130dB Channel Separation

The LT1457 is a dual, JFET input op amp optimized for

handling large capacitive loads in combination with preci-

sion performance.

Precision specifications include 220µV offset voltage in

plastic and surface mount packages. At 70°C input bias

current is 50pA, input offset current is 20pA. Channel

separation is 130dB.

Other dual JFET input op amps from Linear Technology

include the LT1057, which is three times faster than the

LT1457 but at the expense of significantly lower capacitive

load handling capability; and the LT1113 with 4.5nV/√Hz

voltage noise.

Dual, Precision

JFET Input Op Amp

FEATURES

DESCRIPTION

= ±15V

= 25°C

= +1

CAPACITIVE LOAD (nF)

100

OVERSHOOT (%)

100

LT11457• TA01

0.1 1 10

Capacitive Load Handling

Input Offset Voltage Distribution

S8 Package

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Sample-and-Hold (Drives Large Hold Capacitors)

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A/D and D/A Converters

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Photodiode Amplifiers

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Voltage-to-Frequency Converters

APPLICATIONS

TYPICAL PERFORMANCE CHARACTERISTICS

INPUT OFFSET VOLTAGE (mV)

PERCENT OF UNITS

1.0

LT1457 • TA02

–1.0 –0.6 –0.2 0.60.2–0.8 –0.4 0 0.80.4

= ±15V

= 25°C

400 DUALS

(800 OP AMPS)

TESTED FROM

3 RUNS

Summary of content (8 pages)

PAGE 1
LT1457 Dual, Precision JFET Input Op Amp U DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ Handles 10,000pF Capacitive Load 450µV Max Offset Voltage 1200µV Max Offset Voltage in S8 Package 50pA Bias Current at 70°C 13nV/√Hz Voltage Noise 4V/µs Slew Rate 4µV/°C Drift 130dB Channel Separation U APPLICATIONS ■ ■ ■ Sample-and-Hold (Drives Large Hold Capacitors) A/D and D/A Converters Photodiode Amplifiers Voltage-to-Frequency Converters Precision specifications include 220µV offset voltage in plastic and surface mo
PAGE 2
LT1457 W U U W W W Supply Voltage ...................................................... ±20V Differential Input Voltage ....................................... ±40V Input Voltage .......................... Equal to Supply Voltages Output Short-Circuit Duration .......................... Indefinite Operating Temperature Range ................ – 40°C to 85°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec)..................
PAGE 3
LT1457 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER CONDITIONS GBW Gain-Bandwidth Product (Note 5) IS Supply Current Per Amplifier Channel Separation IOS IB AVOL CMRR PSRR VOUT IS Average Temperature Coefficient of Input Offset Voltage (Note 4) Input Offset Current Input Bias Current Large-Signal Voltage Gain Common-Mode Rejection Ratio Power Supply Rejection Ratio Output Voltage Swing Supply Current Per Amplifier MIN 1.0 DC to 5kHz, VIN = ±10V IOS IB AVOL CMRR PSRR VOUT IS 1.0 3.0 1.7 1.
PAGE 4
LT1457 U W TYPICAL PERFORMANCE CHARACTERISTICS Input Bias and Offset Current vs Temperature Input Bias Current Over the Common-Mode Range 100 BIAS CURRENT 30 10 OFFSET CURRENT 0 25 50 75 AMBIENT TEMPERATURE (°C) 120 100 TA = 70°C 80 60 40 20 0 –20 –15 100 18 15 12 9 6 0 5 Long Term Drift of Representative Units 50 RL = 2k VS = ±15V VO = ±10V VS = ±15V TA = 25°C 40 300 RL = 1k 100 30 30 20 10 0 –10 –20 –30 –40 10 –50 0 0.2 0.4 0.6 0.8 –0.8 –0.6 –0.4 –0.
PAGE 5
LT1457 U W TYPICAL PERFORMANCE CHARACTERISTICS Common-Mode Rejection Ratio vs Frequency Common-Mode Range vs Temperature 15 120 VS = ±15V TA = 25°C VS = ±5V TO ±17V FOR PSRR VS = ±15V, VCM = ±10.5V FOR CMRR 60 40 20 13 12 CMRR, PSRR (dB) 80 11 ±10 –11 –12 –14 0 10 100 1k 10k 100k FREQUENCY (Hz) 1M –25 0 25 50 TEMPERATURE (°C) LT1457• TPC10 90 –50 100 8 2.0 1.5 GBW (MHz) GBW 4 1.0 SLEW RISE 2 –25 0 25 50 TEMPERATURE (°C) 75 SUPPLY CURRENT PER AMPLIFIER (mA) 2.
PAGE 6
LT1457 U W TYPICAL PERFORMANCE CHARACTERISTICS Large-Signal Response AV = 1, CL = 100pF Small-Signal Response AV = 1, CL = 1000pF LT1457 TPC19 Small-Signal Response AV = 1, CL = 10,000pF LT1457 TPC20 LT1457 TPC21 U W U U APPLICATIONS INFORMATION Phase Reversal Protection Most industry standard JFET input single, dual, and quad op amps (e.g.
PAGE 7
LT1457 U U W U APPLICATIONS INFORMATION High Speed Operation When the feedback around the op amp is resisitive (RF), a pole will be created with RF, the source resistance and capacitance (RS, CS), and the amplifier input capacitance (CIN ≈ 4pF). In low closed loop gain configurations and with RS and RF in the kilohm range, this pole can create excess phase shift and even oscillation on high speed amplifiers. Because the LT1457’s phase margin is very high, this problem is minimal.
PAGE 8
LT1457 U.S. Area Sales Offices NORTHEAST REGION Linear Technology Corporation One Oxford Valley 2300 E. Lincoln Hwy.,Suite 306 Langhorne, PA 19047 Phone: (215) 757-8578 FAX: (215) 757-5631 SOUTHEAST REGION Linear Technology Corporation 17060 Dallas Parkway Suite 208 Dallas, TX 75248 Phone: (214) 733-3071 FAX: (214) 380-5138 SOUTHWEST REGION Linear Technology Corporation 22141 Ventura Blvd.