Self-Contained Audio Preamplifier

a FEATURES Excellent Noise Performance: 950 pV/√Hz or 1.5 dB Noise Figure Ultralow THD: < 0.01% @ G = 100 Over the Full Audio Band Wide Bandwidth: 1 MHz @ G = 100 High Slew Rate: 17 V/ s typ Unity Gain Stable True Differential Inputs Subaudio 1/f Noise Corner 8-Pin Mini-DIP with Only One External Component Required Very Low Cost Extended Temperature Range: –40 C to +85 C APPLICATIONS Audio Mix Consoles Intercom/Paging Systems Two-Way Radio Sonar Digital Audio Systems Self-Contained Audio Preamplifier SSM2017 FUNCTIONAL BLOCK DIAGRAM V+ SSM2017 V– +IN –IN RG1 RG2 5kΩ 5kΩ X1 5kΩ X1 5kΩ 5kΩ 5kΩ REFERENCE OUT V– PIN CONNECTIONS Epoxy Mini-DIP (P Suffix) RG1 1 –IN 2 8 RG2 V+ OUT REFERENCE SSM2017 TOP VIEW (Not to Scale) 7 6 5 GENERAL DESCRIPTION +IN 3 V– 4 The SSM2017 is a latest generation audio preamplifier, combining SSM preamplifier design expertise with advanced processing. The result is excellent audio performance from a selfcontained 8-pin mini-DIP device, requiring only one external gain set resistor or potentiometer. The SSM2017 is further enhanced by its unity gain stability. Key specifications include ultralow noise (1.5 dB noise figure) and THD (<0.01% at G = 100), complemented by wide bandwidth and high slew rate. Applications for this low cost device include microphone preamplifiers and bus summing amplifiers in professional and consumer audio equipment, sonar, and other applications requiring a low noise instrumentation amplifier with high gain capability. 16-Pin Wide Body SOL (S Suffix) NC RG1 NC –IN +IN NC V– NC 1 2 3 4 5 6 7 8 NC = NO CONNECT 16 15 14 NC RG2 NC V+ NC OUT REFERENCE NC SSM2017 TOP VIEW TOP VIEW (Not to Scale) (Not to Scale) 13 12 11 10 9 REV. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 617/329-4700 World Wide Web Site: http://www.analog.com Fax: 617/326-8703 © Analog Devices, Inc., 1997 (V = V and ≤ ≤ SSM2017–SPECIFICATIONS fications15apply at–40=C+25T C.)+85 C, unless otherwise noted. Typical speciT S A A Parameter DISTORTION PERFORMANCE Total Harmonic Distortion Plus Noise Symbol Conditions TA = +25°C VO = 7 V rms RL = 5 kΩ G = 1000, f = 1 kHz G = 100, f = 1 kHz G = 10, f = 1 kHz G = 1, f = 1 kHz f = 1 kHz, G = 1000 f = 1 kHz; G = 100 f = 1 kHz; G = 10 f = 1 kHz; G = 1 f = 1 kHz, G = 1000 G = 10 RL = 4.7 kΩ CL = 50 pF TA = +25°C G = 1000 G = 100 G = 10 G=1 Min Typ Max Units THD+N 0.012 0.005 0.004 0.008 0.95 1.95 11.83 107.14 2 10 17 % % % % nV/√Hz nV/√Hz nV/√Hz nV/√Hz pA/√Hz V/µs NOISE PERFORMANCE Input Referred Voltage Noise Density en Input Current Noise Density DYNAMIC RESPONSE Slew Rate in SR Small Signal Bandwidth BW–3 dB 200 1000 2000 4000 0.1 1.2 6 25 ± 0.002 ± 2.5 80 60 40 26 20 80 60 40 26 ±8 112 92 74 54 54 124 118 101 82 1 30 5.3 7.1 ± 11.0 ± 12.3 –40 2 4.7 50 ± 50 kHz kHz kHz kHz mV µA µA dB dB dB dB dB dB dB dB dB V MΩ MΩ MΩ MΩ V mV kΩ kΩ pF mA sec INPUT Input Offset Voltage Input Bias Current Input Offset Current Common-Mode Rejection VIOS IB Ios CMR Power Supply Rejection PSR VCM = 0 V VCM = 0 V VCM = ± 8 V G = 1000 G = 100 G = 10 G = 1, TA = +25°C G = 1, TA = – 40°C to +85°C VS = ± 6 V to ± 18 V G = 1000 G = 100 G = 10 G=1 Differential, G = 1000 G=1 Common Mode, G = 1000 G=1 RL = 2 kΩ; TA = +25°C TA = +25°C TA = –40°C to +85°C Input Voltage Range Input Resistance IVR RIN OUTPUT Output Voltage Swing Output Offset Voltage Minimum Resistive Load Drive Maximum Capacitive Load Drive Short Circuit Current Limit Output Short Circuit Duration GAIN Gain Accuracy VO VOOS 500 ISC Output-to-Ground Short 10 10 kΩ G–1 TA = +25°C RG = 10 Ω, G = 1000 RG = 101 Ω, G = 100 RG = 1.1 kΩ, G = 10 RG = , G = 1 RG = Maximum Gain REFERENCE INPUT Input Resistance Voltage Range Gain to Output POWER SUPPLY Supply Voltage Range Supply Current Specifications subject to change without notice. G 0.25 0.20 0.20 0.05 70 10 ±8 1 1 1 1 0.5 dB dB dB dB dB kΩ V V/V VS ISY ±6 VCM = 0 V, RL = ± 10.6 ± 22 ± 14.0 V mA –2– REV. C SSM2017 Typical Performance Characteristics Figure 1. Typical THD+Noise* at G = 1, 10, 100, 1000; VO = 7 V rms, VS = ± 15 V, RL = 5 kΩ; TA = +25°C *80 kHz low-pass filter used for Figures 1-2. Figure 2. Typical THD+ Noise * at G = 2, 10, 100, 1000; VO = 10 V rms, VS = ± 18 V, RL = 5 kΩ; TA = +25°C ABSOLUTE MAXIMUM RATINGS Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 22 V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Voltage Output Short Circuit Duration . . . . . . . . . . . . . . . . . . . 10 sec Storage Temperature Range (P, Z Packages) –65°C to +150°C Junction Temperature (TJ) . . . . . . . . . . . . . –65°C to +150°C Lead Temperature Range (Soldering, 60 sec) . . . . . . . . 300°C Operating Temperature Range . . . . . . . . . . . . –40°C to +85°C Thermal Resistance* 8-Pin Hermetic DIP (Z): θJA = 134; θJC = 12 . . . . . . °C/W 8-Pin Plastic DIP (P): θJA = 96; θJC = 37 . . . . . . . . . . °C/W 16-Pin SOIC (S): θJA = 92; θJC = 27 . . . . . . . . . . . . . °C/W *θJA is specified for worst case mounting conditions, i.e., θJA is specified for device in socket for cerdip and plastic DIP; θJA is specified for device soldered to printed circuit board for SOL package. ORDERING GUIDE Model SSM2017P SSM2017S SSM2017S-REEL Temperature Range* –40°C to +85°C –40°C to +85°C –40°C to +85°C Package Description 8-Pin Plastic DIP 16-Lead SOL 16-Lead SOL Package Option N-8 R-16 R-16 *XIND = –40°C to +85°C. CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the SSM2017 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. WARNING! ESD SENSITIVE DEVICE REV. C –3– SSM2017 Figure 3. Voltage Noise Density vs. Frequency Figure 4. RTI Voltage Noise Density vs. Gain Figure 5. Output Impedance vs. Frequency Figure 6. Maximum Output Swing vs. Frequency Figure 7. Maximum Output Voltage vs. Load Resistance Figure 8. Input Voltage Range vs. Supply Voltage Figure 9. Output Voltage Range vs. Supply Voltage Figure 10. CMRR vs. Frequency Figure 11. +PSRR vs. Frequency –4– REV. C SSM2017 Figure 12. –PSRR vs. Frequency Figure 13. VIOS vs. Temperature Figure 14. VIOS vs. Supply Voltage Figure 15. VOOS vs. Temperature Figure 16. VOOS vs. Supply Voltage Figure 17. IB vs. Temperature Figure 18. IB vs. Supply Voltage Figure 19. ISY vs. Temperature Figure 20. ISY vs. Supply Voltage REV. C –5– SSM2017 G= V OUT   =  10 k  +1 (+In) – (In) RG   Figure 21. Bandwidth of the SSM2017 for Various Values of Gain NOISE PERFORMANCE Basic Circuit Connections GAIN The SSM2017 only requires a single external resistor to set the voltage gain. The voltage gain, G, is: 10 kΩ +1 RG G= and RG = 10 kΩ G –1 The SSM2017 is a very low noise audio preamplifier exhibiting a typical voltage noise density of only 1 nV/√Hz at 1 kHz. The exceptionally low noise characteristics of the SSM2017 are in part achieved by operating the input transistors at high collector currents since the voltage noise is inversely proportional to the square root of the collector current. Current noise, however, is directly proportional to the square root of the collector current. As a result, the outstanding voltage noise performance of the SSM2017 is obtained at the expense of current noise performance. At low preamplifier gains, the effect of the SSM2017’s voltage and current noise is insignificant. The total noise of an audio preamplifier channel can be calculate by: En = en 2 +(in RS )2 + et 2 For convenience, Table I lists various values of RG for common gain levels. Table I. Values of RG for Various Gain Levels AV 1 3.2 10 31.3 100 314 1000 dB 0 10 20 30 40 50 60 RG NC 4.7k 1.1k 330 100 32 10 where: En = total input referred noise en = amplifier voltage noise in = amplifier current noise RS = source resistance et = source resistance thermal noise. For a microphone preamplifier, using a typical microphone impedance of 150 Ω the total input referred noise is: en = 1 nV/√Hz @ 1 kHz, SSM2017 en in = 2 pA/√Hz @ 1 kHz, SSM2017 in RS = 150 Ω, microphone source impedance et = 1.6 nV/√Hz @ 1 kHz, microphone thermal noise En =√(1 nV√Hz)2 + 2 (pA/√Hz × 150 Ω)2 + (1.6 nV/√Hz)2 = 1.93 nV/√Hz @ 1 kHz. This total noise is extremely low and makes the SSM2017 virtually transparent to the user. The voltage gain can range from 1 to 3500. A gain set resistor is not required for unity gain applications. Metal-film or wirewound resistors are recommended for best results. The total gain accuracy of the SSM2017 is determined by the tolerance of the external gain set resistor, RG, combined with the gain equation accuracy of the SSM2017. Total gain drift combines the mismatch of the external gain set resistor drift with that of the internal resistors (20 ppm/°C typ). Bandwidth of the SSM2017 is relatively independent of gain as shown in Figure 21. For a voltage gain of 1000, the SSM2017 has a small-signal bandwidth of 200 kHz. At unity gain, the bandwidth of the SSM2017 exceeds 4 MHz. –6– REV. C SSM2017 INPUTS The SSM2017 has protection diodes across the base emitter junctio