LINEAR TECHNOLOGY LT1115 Data Sheet

LT1115

Ultralow Noise,

Low Distortion, Audio Op Amp

FEATURES DESCRIPTIO Voltage Noise: 1.2n V/√Hz Max at 1k Hz The LT®1115 is the lowest noise audio operational ampli-

0.9n V/√Hz Typ at 1k Hz fier available. This ultralow noise performance (0.9n V/√Hz

Voltage and Current Noise 100% Tested at 1k Hz) is combined with high slew rates (>15V/µs) and

Gain-Bandwidth Product: 40MHz Min very low distortion specifications.

Slew Rate: 10V/µs Min

The RIAA circuit shown below using the LT1115 has very

Voltage Gain: 2 Million Min

low distortion and little deviation from ideal RIAA

■ Low THD at 10k Hz, AV = –10, RL = 600Ω: 0.002%

response (see graph).

VO = 7VRMS Low IMD, CCIF Method, AV = +10: 0.002% , LTC and LT are registered trademarks of Linear Technology Corporation. RL = 600Ω VO = 7VRMS

APPLICATIO S High Quality Audio Preamplifiers Low Noise Microphone Preamplifiers Very Low Noise Instrumentation Amplifiers

DE VI AT IO (d B)

Low Noise Frequency Synthesizers Infrared Detector Amplifiers Hydrophone Amplifiers Low Distortion Oscillators

TYPICAL APPLICATIO

RIAA Phonograph Preamplifier (40/60db Gain)

Measured Deviation from RIAA

1µF 1µF RBOOST

35V 35V 49.9Ω Response. lnput at 1k Hz = 1m VRMS

+INPUT

Pre-Emphasized

OUTPUT

RIN 47.5k (MM) LT1115 LT1010CT 1.0000

100Ω (MC) VS 18V

(SELECT 2N4304*

RL 0.80000 RS 25Ω

PER ~250Ω 3900p F

25k TA 25°C

COM SELECT 0.60000

PHOTO 2m A

CART- FOR 2m A

RIDGE) 1µF

–18V MEASURED

499Ω 17.8k 210k –0.2000 COMPUTER

18VV+ SIMULATED

COM –0.8000

470µF 210Ω OPEN—MM –1.000

35V CLOSED—MC 1k 10k 50k

SINGLE 3900p F RESISTORS 1%

POINT *OR USE 2m A CURRENT SOURCE FREQUENCY (Hz) LT1115 • TA02

BOARD 82.5k MM = MOVING MAGNET

GROUND MC = MOVING COIL

2200µF 4.7µF NOTE: BYPASS SUPPLIES WITH LOW ESR CAPS LT1115 • TA01 16V FILM OTHER CAPS: HIGH QUALITY FILM

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