Datasheet

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LT1115

1115fa

Ultralow Noise,

Low Distortion, Audio Op Amp

■

High Quality Audio Preamplifiers

■

Low Noise Microphone Preamplifiers

■

Very Low Noise Instrumentation Amplifiers

■

Low Noise Frequency Synthesizers

■

Infrared Detector Amplifiers

■

Hydrophone Amplifiers

■

Low Distortion Oscillators

RIAA Phonograph Preamplifier (40/60db Gain)

Measured Deviation from RIAA

Response. lnput at 1kHz = 1mV

RMS

Pre-Emphasized

FREQUENCY (Hz)

–0.2000

DEVIATION (dB)

0.0

0.20000

0.40000

0.60000

100

1k 10k 50k

–0.4000

–0.6000

–0.8000

–1.000

0.80000

1.0000

= ± 18V

=25Ω

=25

MEASURED

COMPUTER

SIMULATED

LT1115 • TA02

–

INPUT

(SELECT

PER

PHOTO

CART-

RIDGE)

COM

47.5k (MM)

100Ω (MC)

18V 18V

–18V

18V

–

–18V

1µF

35V

1µF

35V

470µF

35V

2200µF

16V

4.7µF

FILM

470µF

35V

1µF

35V

1µF

35V

100Ω

49.9Ω

562Ω

499Ω

22.6Ω

330pF

15nF

2N4304*

~250Ω

SELECT

FOR 2mA

RESISTORS 1%

*OR USE 2mA CURRENT SOURCE

MM = MOVING MAGNET

MC = MOVING COIL

BYPASS SUPPLIES WITH LOW ESR CAPS

OTHER CAPS: HIGH QUALITY FILM

NOTE:

2mA

17.8k

82.5k

210k

25k

210Ω

3900pF

SINGLE

POINT

BOARD

GROUND

OPEN—MM

CLOSED—MC

COM

BOOST

OUTPUT

LT1115

LT1010CT

LT1115 • TA01

+ +

FEATURES

APPLICATIO S

DESCRIPTIO

TYPICAL APPLICATIO

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

■

Voltage Noise: 1.2nV/√Hz Max at 1kHz

0.9nV/√Hz Typ at 1kHz

■

Voltage and Current Noise 100% Tested

■

Gain-Bandwidth Product: 40MHz Min

■

Slew Rate: 10V/µs Min

■

Voltage Gain: 2 Million Min

■

Low THD at 10kHz, A

= –10, R

= 600Ω: 0.002%

= 7V

RMS

■

Low IMD, CCIF Method, A

= +10: 0.002%

= 600Ω

= 7V

RMS

The LT

1115 is the lowest noise audio operational ampli-

fier available. This ultralow noise performance (0.9nV/√Hz

at 1kHz) is combined with high slew rates (>15V/µs) and

very low distortion specifications.

The RIAA circuit shown below using the LT1115 has very

low distortion and little deviation from ideal RIAA

response (see graph).

Summary of content (16 pages)

PAGE 1
LT1115 Ultralow Noise, Low Distortion, Audio Op Amp U FEATURES ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LT ®1115 is the lowest noise audio operational amplifier available. This ultralow noise performance (0.9nV/√Hz at 1kHz) is combined with high slew rates (>15V/µs) and very low distortion specifications. Voltage Noise: 1.2nV/√Hz Max at 1kHz 0.
PAGE 2
LT1115 W W W AXI U U ABSOLUTE RATI GS (Note 1) Supply Voltage ...................................................... ±22V Differential Input Current (Note 5) ...................... ±25mA Input Voltage ............................ Equal to Supply Voltage Output Short-Circuit Duration .......................... Indefinite Operating Temperature Range ..................... 0°C to 70°C Storage Temperature Range ..................–65°C to 150°C Lead Temperature (Soldering, 10 sec)..................
PAGE 3
LT1115 ELECTRICAL CHARACTERISTICS VS = ±18V, TA = 25°C, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP CMRR Common Mode Rejection Ratio VCM = ±13.5V 104 123 dB PSRR Power Supply Rejection Ratio VS = ±4V to ±19V 104 126 dB AVOL Large-Signal Voltage Gain 2.0 1.5 1.0 20 15 10 V/µV V/µV V/µV VOUT Maximum Output Voltage Swing RL ≥ 2kΩ, Vo = ±14.5V RL ≥ 1kΩ, Vo = ±13V RL ≥ 600Ω, Vo = ±10V No Load RL ≥ 2kΩ RL ≥ 600Ω ±15.5 ±14.5 ±11.0 ±16.5 ±15.5 ±14.
PAGE 4
LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS Wideband Voltage Noise (0.1Hz to Frequency Indicated) Wideband Noise, DC to 20kHz Total Noise vs Matched Source Resistance 10 100 FPO RS TOTAL NOISE DENSITY (nV/√Hz) RMS VOLTAGE NOISE (µV) 0.5µV/DIV VS = ± 18V TA = 25°C 1 0.1 – RS + 10 AT 1kHz AT 10Hz 2 RS NOISE ONLY 1.0 VS = ± 18V TA = 25°C 0.5ms/DIV 0.01 100 1k 100k 10k BANDWIDTH (Hz) 1M 0.
PAGE 5
LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS AV = 10 RL = 600 TA = 25°C VS = ±18V 0.010 0.001 0.1 1 OUTPUT AMPLITUDE (VRMS) 10 100 0.1 0.010 0.001 0.0001 10m 10 SLEW LT1115 • TPC12 Voltage Noise vs Temperature 2.0 VS = ± 18V TA = 25°C 0.1 1 10 TYPICAL 1 1/f CORNER = 250Hz 0.1 10 3 10 30 100 300 1k 3k 10k UNMATCHED SOURCE RESISTANCE, RS (Ω) RMS VOLTAGE NOISE DENSITY (nV/√Hz) CURRENT NOISE DENSITY (pA/√Hz) RS NOISE ONLY 1.
PAGE 6
LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS Gain, Phase vs Frequency 60 120 50 50 40 40 100 80 60 40 70 0 60 30 30 GAIN 20 20 10 VS = ±18V TA = 25°C CL = 10pF 0 –20 0.01 0.
PAGE 7
LT1115 U W TYPICAL PERFOR A CE CHARACTERISTICS Maximum Output vs Frequency (Power Bandwidth*) PEAK-TO-PEAK OUTPUT VOLTAGE (V) 20mV/DIVISION 30 FPO 0.2µs/DIVISION AV = –1, RS = Rf = 2kΩ Cf = 30pF CL = 80pF Closed-Loop Output Impedance 100 VS = ±18V TA = 25°C RL = 2kΩ 25 OUTPUT IMPEDANCE (Ω) Small-Signal Transient Response 20 15 *POWER BANDWIDTH SLEW RATE fP = πEOP 5 f = POWER BANDWIDTH P EP-P = PEAK-TO-PEAK AMPLIFIER 10 0 10k 1 AV = 1000 0.1 AV = 5 0.
PAGE 8
LT1115 U W U U APPLICATIO S I FOR ATIO Therefore, to realize truly low noise performance it is important to understand the interaction between voltage noise (en), current noise (in) and resistor noise (rn). Total Noise vs Source Resistance The total input referred noise of an op amp is given by et = [en2 + rn2 + (inReq)2]1/2 where Req is the total equivalent source resistance at the two inputs and rn = √4kTReq = 0.
PAGE 9
LT1115 U TYPICAL APPLICATIO S R1 1k, 0.1% R3 316k, 0.1% 18V + 2 – LT1115 3 + 100 1% OUT 4 –18V R2 1k, 0.1% 4.7µF FILM 6 + 1µF 35V LOW ESR 10k 1% NOTE: MATCH RESISTOR PAIRS R1 = R3 TO ± 0.1% R4 R2 R4 316k, 0.1% LT1115 • TA03 Figure 1. Balanced Transformerless Microphone Preamp THD + Noise vs Frequency (Figure 1) TOTAL HARMONIC DISTORTION + NOISE (%) INPUT RP 30k 1% 1µF 35V LOW ESR 7 1 TA = 25°C RL = 100kΩ VIN = 10mVRMS VOUT = 2.92VRMS RS = 150Ω 0.1 0.
PAGE 10
LT1115 U TYPICAL APPLICATIO S 18V 18V 49.9Ω + INPUT R1 100Ω 3 C1 33pF 8 – 4 1 V+ 100Ω 6 IN RL V– 2N4304* R2 909Ω + ~250Ω SELECT FOR 2mA + 33.2k 1% OUTPUT LT1010CT 2mA –18V 1µF 35V 1µF 35V 7 + LT1115 2 + RBOOST 1µF 35V –18V RESISTORS 1% METAL FILM CAPACITORS – BYPASS; LOWER ESR OTHER: POLYESTER OR OTHER 1µF HIGH QUALITY FILM. 35V *OR USE 2mA CURRENT SOURCE. 33.
PAGE 11
LT1115 U TYPICAL APPLICATIO S 100pF GAIN: 40dB 30dB 24.9Ω 75Ω 475Ω 2.49k 18V 0.
PAGE 12
LT1115 U TYPICAL APPLICATIO S 18V 1µF 35V + + 470µF 35V 100pF RIAA NETWORK 2.49k + 1µF 2 3 100Ω + 35V R1 6081Ω 6 LT1115 3 0.01µF 7 + 4.7µF FILM 6 LT1056 4 + MOVING COIL INPUT 7 – 1µF 35V C1 0.1645µF 2 R2 490Ω C2 0.483µF – OUTPUT 499Ω 4 100k 10k 499Ω + 12.1Ω 1µF 35V –18V RESISTORS 1% METAL FILM CAPACITORS—BYPASS: LOW ESR OTHER: HIGH QUALITY FILM NOTE 1: 1kHz GAIN = 53dB NOTE 2: IN RIAA NETWORK VALUES SHOWN ARE MEASURED AND PRODUCE THE “DEVIATION FROM RIAA” GRAPH SHOWN.
PAGE 13
LT1115 U TYPICAL APPLICATIO S 470µF 35V 18V + 2.5k REV. AUDIO 1µF 35V TAPER + + 1N4002 100pF 4.99Ω 2 RED 100Ω 3 YELLOW 7 – + V+ 22Ω 100Ω 6 LT1115 1µF 35V 49.9Ω BOOST IN 2.49k 10Ω LT1010CT BRN OUT 4 OPTIONAL SINGLE-ENDED TO BALANCED OUTPUT TRANSFORMER V– 2N4304** RED 150Ω MICROPHONE INPUT 6.
PAGE 14
LT1115 U TYPICAL APPLICATIO S R1 2k 200Ω 15V + 3 2k 200Ω + 1µF – 6 + 470µF 35V 1µF 35V + 100Ω – 15V RBOOST = 49.9Ω 2 IN 1 4 LT1010 2 3 500Ω (20T) 2.4k 20VP-P OUTPUT 5 3 4 1µF 35V –15V 5.6k –15V + 15V 2 LT1022 4 7 + 7 35V 1µF 35V LT1115 R2 15V C2 0.1µF FILM + 1µF 35V + C1 0.1µF FILM 1µF 35V 4.7k 10pF –15V 10µF + + –15V MOUNT, 1N4148's IN CLOSE PROXIMITY 1k 1 2πRC WHERE R1C1 = R2C2 MEASURED WITH R1 = R2 = 1.5k 120k –15V 470µF 35V 1µF 10k + + 10k 2.
PAGE 15
LT1115 U PACKAGE DESCRIPTIO N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( 8.255 +0.889 –0.381 ) .045 – .065 (1.143 – 1.651) .130 ± .005 (3.302 ± 0.127) .065 (1.651) TYP .100 (2.54) BSC .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 NOTE: 1.
PAGE 16
LT1115 U PACKAGE DESCRIPTIO SW Package 16-Lead Plastic Small Outline (Wide .300 Inch) (Reference LTC DWG # 05-08-1620) .050 BSC .045 ±.005 .030 ±.005 TYP .398 – .413 (10.109 – 10.490) NOTE 4 16 N 15 14 13 12 11 10 9 N .325 ±.005 .420 MIN .394 – .419 (10.007 – 10.643) NOTE 3 1 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT 1 .005 (0.127) RAD MIN .009 – .013 (0.229 – 0.330) .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737) 2 3 4 5 6 .093 – .104 (2.362 – 2.