a FEATURES Excellent Noise Performance: 1.0 nV/÷Hz or 1.5 dB Noise Figure Ultra-low THD: < 0.01% @ G = 100 Over the Full Audio Band Wide Bandwidth: 1 MHz @ G = 100 High Slew Rate: 16 V/s @ G = 10 10 V rms Full-Scale Input, G = 1, VS = 18 V Unity Gain Stable True Differential Inputs Subaudio 1/f Noise Corner 8-Lead PDIP or 16-Lead SOIC Only One External Component Required Very Low Cost Extended Temperature Range: –40C to +85C APPLICATIONS Audio Mix Consoles Intercom/Paging Systems 2-Way Radio Sonar Digital Audio Systems GENERAL DESCRIPTION The SSM2019 is a latest generation audio preamplifier, combining SSM preamplifier design expertise with advanced processing. The result is excellent audio performance from a monolithic device, requiring only one external gain set resistor or potentiometer. The SSM2019 is further enhanced by its unity gain stability. Key specifications include ultra-low 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. Self-Contained Audio Preamplifier SSM2019 FUNCTIONAL BLOCK DIAGRAM V+ V– +IN 1 –IN RG1 5k 1 5k RG2 5k 5k OUT 5k 5k REFERENCE V– PIN CONNECTIONS 8-Lead PDIP (N Suffix) 8-Lead Narrow Body SOIC (RN Suffix)* 8 RG1 1 SSM2019 RG2 V+ TOP VIEW +IN 3 (Not to Scale) 6 OUT –IN 2 V– 4 7 5 REFERENCE 16-Lead Wide Body SOIC (RW Suffix) 16 NC NC 1 15 RG2 RG1 2 NC 3 –IN 4 14 NC SSM2019 13 V+ TOP VIEW +IN 5 (Not to Scale) 12 NC NC 6 11 OUT V– 7 10 REFERENCE NC 8 9 NC NC = NO CONNECT *Consult factory for availability. REV. A 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 that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective companies. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/461-3113 © 2011 Analog Devices, Inc. All rights reserved. V and –40C £ T £ +85C, unless otherwise noted. Typical specifications SSM2019–SPECIFICATIONS (Vapply= 15 at T = 25C.) S A A Parameter Symbol Conditions Min Typ Max Unit DISTORTION PERFORMANCE Total Harmonic Distortion Plus Noise NOISE PERFORMANCE Input Referred Voltage Noise Density Input Current Noise Density DYNAMIC RESPONSE Slew Rate Small Signal Bandwidth INPUT Input Offset Voltage Input Bias Current Input Offset Current Common-Mode Rejection Power Supply Rejection Input Voltage Range Input Resistance OUTPUT Output Voltage Swing Output Offset Voltage Maximum Capacitive Load Drive Short Circuit Current Limit Output Short Circuit Duration GAIN Gain Accuracy Maximum Gain THD + N en in SR BW–3 dB VIOS IB Ios CMR PSR IVR RIN VO = 7 V rms RL = 2 kW f = 1 kHz, G = 1000 f = 1 kHz, G = 100 f = 1 kHz, G = 10 f = 1 kHz, G = 1 BW = 80 kHz 0.017 0.0085 0.0035 0.005 % % % % 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 1.0 1.7 7 50 2 nV/÷Hz nV/÷Hz nV/÷Hz nV/÷Hz pA/÷Hz G = 10 RL = 2 kW CL = 100 pF G = 1000 G = 100 G = 10 G=1 16 V/ms 200 1000 1600 2000 kHz kHz kHz kHz 0.05 0.25 3 10 ± 0.001 ± 1.0 mV mA mA 110 90 70 50 130 113 94 74 dB dB dB dB 110 110 90 70 ± 12 124 118 101 82 1 30 5.3 7.1 dB dB dB dB V MW MW MW MW ± 13.5 ± 13.9 4 30 5000 ± 50 Continuous V mV pF mA sec 0.5 0.5 0.5 0.1 0.1 0.2 0.2 0.2 70 dB dB dB dB dB 10 ± 12 1 kW V V/V VCM = 0 V VCM = 0 V VCM = ± 12 V G = 1000 G = 100 G = 10 G=1 VS = ± 5 V to ± 18 V G = 1000 G = 100 G = 10 G=1 Differential, G = 1000 G=1 Common Mode, G = 1000 G=1 VO VOOS RL = 2 kW, TA = 25∞C ISC Output-to-Ground Short RG = 10 kW G–1 TA = 25∞C RG = 10 W, G = 1000 RG = 101 W, G = 100 RG = 1.1 kW, G = 10 RG = , G = 1 G REFERENCE INPUT Input Resistance Voltage Range Gain to Output POWER SUPPLY Supply Voltage Range Supply Current VS ISY VCM = 0 V, RL = VCM = 0 V, VS = ± 18 V, RL = ±5 ± 4.6 ± 4.7 ± 18 ± 7.5 ± 8.5 V mA mA Specifications subject to change without notice. –2– REV. A SSM2019 ABSOLUTE MAXIMUM RATINGS 1 Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 19 V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Voltage Output Short Circuit Duration . . . . . . . . . . . . . . . . . . . 10 sec Storage Temperature Range . . . . . . . . . . . . –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 Resistance2 8-Lead PDIP (N) . . . . . . . . . . . . . . . . . . . . . . . JA = 96∞C/W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JC = 37∞C/W 16-Lead SOIC (RW) . . . . . . . . . . . . . . . . . . . . JA = 92∞C/W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JC = 27∞C/W NOTES 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 qJA is specified for worst-case mounting conditions, i.e., qJA is specified for device in socket for PDIP; qJA is specified for device soldered to printed circuit board for SOIC package. 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 SSM2019 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 Typical Performance Characteristics 100 RTI, VOLTAGE NOISE DENSITY – nV/ Hz 0.1 G = 1000 G = 100 THD + N – % 0.01 G=1 G = 10 0.001 ⴞ15V VS ⴞ18V 7Vrms VO 10Vrms RL 600⍀ BW = 80kHz 0.0001 10 20 100 1k FREQUENCY – Hz 10 1 0.1 10k 20k 1 10 100 1k 10k FREQUENCY – Hz TPC 1. Typical THD + Noise vs. Gain REV. A TA = 25ⴗC VS = ⴞ15V G = 1000 TPC 2. Voltage Noise Density vs. Frequency –3– SSM2019 100 TA = 25 C VS = 15V GAIN 80 IMPEDANCE – 10 f = 1kHz OR 10kHz 1 70 60 50 40 30 20 10 GAIN = 1 25 20 TA = 25 C RL = 2k VS = 15V 15 10 10 100 0 100 1k GAIN G 12 G=1 8 6 4 2 1k 10k 100 LOAD RESISTANCE – 30 10 30 20 SUPPLY VOLTAGE (V+ – V–) – V 150 G = 1000 125 100 +PSRR – dB 75 G=1 25 20 1k 10k FREQUENCY– Hz TPC 9. CMRR vs. Frequency 100k 0 10 G = 100 G = 10 G = 100 G=1 75 50 50 40 40 150 100 G=1 100 0 40 TPC 8. Output Voltage Range vs. Supply Voltage G = 10 60 10 5 0 20 10 125 G = 10 0 10 G = 1000 G = 100 80 10 15 TPC 7. Input Voltage Range vs. Supply Voltage VCM = 100mV 180 VS = 15V TA = 25C 160 100 20 0 200 G = 1000 1M TA = 25 C SUPPLY VOLTAGE (V+ – V–) – V TPC 6. Output Voltage vs. Load Resistance 120 30 0 100k 10k 100k FREQUENCY – Hz 20 TA = 25 C f = 100kHz 10 10 1k TPC 5. Maximum Output Swing vs. Frequency 40 TA = 25 C 14 VS = 15V INPUT SWING (VIN+ – VIN–) – V OUTPUT VOLTAGE – V 16 140 10 100 1M 10k 100k FREQUENCY – Hz TPC 4. Output Impedance vs. Frequency TPC 3. RTI Voltage Noise Density vs. Gain 0 10 1k OUTPUT SWING (VOUT+ – VOUT–) – V 1 –PSRR – dB 0.1 CMRR – dB 30 90 PEAK-TO-PEAK VOLTAGE – V RTI VOLTAGE NOISE DENSITY – nV/ Hz 100 VCM = 100mV TA = 25 C VS = 15V 100 25 1k 10k FREQUENCY – Hz 100k TPC 10. Positive PSRR vs. Frequency –4– 0 10 VS = 100mV TA = 25 C VS = 15V 100 1k 10k FREQUENCY – Hz 100k TPC 11. Negative PSRR vs. Frequency REV. A SSM2019 0.040 0 0.02 V+/V– = TA = 25C –1 0.030 0 –2 0.025 –0.01 –3 0.020 0.015 VOOS – mV 0.01 VIOS – mV VIOS – mV V+/V– = 15V 0.035 –0.02 –0.03 –4 –5 0.010 –0.04 –6 0.005 –0.05 –7 0 –50 –25 0 25 50 TEMPERATURE – C 75 100 –0.06 0 5 10 15 20 25 30 35 SUPPLY VOLTAGE (VCC – VEE) – V –8 –50 40 TPC 13. VIOS vs. Supply Voltage TPC 12. VIOS vs. Temperature 100 TA = 25C 4 4 0 3 IB – A IB – A VOOS – mV 75 5 10 IB+ OR IB– 3 2 2 –10 1 1 –20 0 –50 –30 0 5 10 15 20 25 30 35 SUPPLY VOLTAGE (VCC – VEE) – V 40 TPC 15. VOOS vs. Supply Voltage 0 –25 0 25 50 TEMPERATURE – C 75 100 TPC 16. IB vs. Temperature 8 8 6 6 0 I+ @ V+/V– = 15V 2 0 –2 I– @ V+/V– = 15V –4 –6 I– @ V+/V– = 18V –8 –50 –25 2 0 –2 –4 I– –6 75 TPC 18. Supply Current vs. Temperature REV. A TA = 25 C 14 I+ 4 –8 0 25 50 TEMPERATURE – C 100 40 16 SUPPLY CURRENT – mA SUPPLY CURRENT – mA I+ @ V+/V– = 18V 4 10 20 30 SUPPLY VOLTAGE (VCC – VEE) – V TPC 17. IB vs. Supply Voltage TA = 25C SUPPLY CURRENT – mA 25 0 50 TEMPERATURE – C 6 V+/V– = 15V TA = 25C 20 –25 TPC 14. VOOS vs. Temperature 5 30 15V 12 10 8 6 4 2 0 5 10 15 20 25 30 35 40 SUPPLY VOLTAGE (VCC – VEE) – V TPC 19. Supply Current vs. Supply Voltage –5– 0 0 5 10 15 SUPPLY VOLTAGE – V 20 TPC 20. ISY vs. Supply Voltage SSM2019 V+ VS = ⴞ15V TA = 25ⴗC +IN SSM2019 VOLTAGE GAIN – dB RG1 RG OUT RG2 REFERENCE –IN G= VOUT (+IN) – (– IN) = 10k⍀ RG +1 V– 60 40 20 0 Figure 1. Basic Circuit Connections GAIN 1k The SSM2019 only requires a single external resistor to set the voltage gain. The voltage gain, G, is: G= For convenience, Table I lists various values of RG for common gain levels. Table I. Values of RG for Various Gain Levels NC 4.7 k 1.1 k 330 100 32 10 0 10 20 30 40 50 60 1 3.2 10 31.3 100 314 1000 10M The SSM2019 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 SSM2019 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 SSM2019 is obtained at the expense of current noise performance. At low preamplifier gains, the effect of the SSM2019 voltage and current noise is insignificant. 10 kW G –1 dB 1M NOISE PERFORMANCE and the external gain resistor, RG , is: RG (⍀) AV 100k Figure 2. Bandwidth for Various Values of Gain 10 kW +1 RG RG = 10k The total noise of an audio preamplifier channel can be calculated by: E n = e n 2 + ( i n RS )2 + e t 2 where: En = total input referred noise en = amplifier voltage noise in = amplifier current noise The voltage gain can range from 1 to 3500. A gain set resistor is not required for unity gain applications. Metal film or wire-wound resistors are recommended for best results. RS = source resistance et = source resistance thermal noise The total gain accuracy of the SSM2019 is determined by the tolerance of the external gain set resistor, RG, combined with the gain equation accuracy of the SSM2019. Total gain drift combines the mismatch of the external gain set resistor drift with that of the internal resistors (20 ppm/∞C typ). For a microphone preamplifier, using a typical microphone impedance of 150 W, the total input referred noise is: Bandwidth of the SSM2019 is relatively independent of gain, as shown in Figure 2. For a voltage gain of 1000, the SSM2019 has a small-signal bandwidth of 200 kHz. At unity gain, the bandwidth of the SSM2019 exceeds 4 MHz. 1.93 nV / Hz @ 1 kHz E n = (1 nV Hz )2 + 2( pA / Hz ¥ 150 W)2 + (1.6 nV / Hz )2 = where: en = 1 nV/÷Hz @ 1 kHz, SSM2019 en in = 2 pA/÷Hz @ 1 kHz, SSM2019 in RS = 150 W, microphone source impedance et = 1.6 nV/÷Hz @ 1 kHz, microphone thermal noise This total noise is extremely low and makes the SSM2019 virtually transparent to the user. –6– REV. A SSM2019 Although the SSM2019 inputs are fully floating, care must be exercised to ensure that both inputs have a dc bias connection capable of maintaining them within the input common-mode range. The usual method of achieving this is to ground one side of the transducer as in Figure 3a. An alternative way is to float the transducer and use two resistors to set the bias point as in Figure 3b. The value of these resistors can be up to 10 kW, but they should be kept as small as possible to limit common-mode pickup. Noise contribution by resistors is negligible since it is attenuated by the transducer’s impedance. Balanced transducers give the best noise immunity and interface directly as in Figure 3c. INPUTS The SSM2019 has protection diodes across the base emitter junctions of the input transistors. These prevent accidental avalanche breakdown, which could seriously degrade noise performance. Additional clamp diodes are also provided to prevent the inputs from being forced too far beyond the supplies. (INVERTING) SSM2019 TRANSDUCER (NONINVERTING) For stability, it is required to put an RF bypass capacitor directly across the inputs, as shown in Figures 3 and 4. This capacitor should be placed as close as possible to the input terminals. Good RF practice should also be followed in layout and power supply bypassing, since the SSM2019 uses very high bandwidth devices. a. Single-Ended R TRANSDUCER R REFERENCE TERMINAL SSM2019 The output signal is specified with respect to the reference terminal, which is normally connected to analog ground. The reference may also be used for offset correction or level shifting. A reference source resistance will reduce the common-mode rejection by the ratio of 5 kW/RREF. If the reference source resistance is 1 W, then the CMR will be reduced to 74 dB (5 kW/1 W = 74 dB). b. Pseudo-Differential COMMON-MODE REJECTION Ideally, a microphone preamplifier responds to only the difference between the two input signals and rejects common-mode voltages and noise. In practice, there is a small change in output voltage when both inputs experience the same common-mode voltage change; the ratio of these voltages is called the common-mode gain. Common-mode rejection (CMR) is the logarithm of the ratio of differential-mode gain to common-mode gain, expressed in dB. SSM2019 TRANSDUCER c. True Differential Figure 3. Three Ways of Interfacing Transducers for High Noise Immunity PHANTOM POWERING A typical phantom microphone powering circuit is shown in Figure 4. Z1 to Z4 provide transient overvoltage protection for the SSM2019 whenever microphones are plugged in or unplugged. +48V C1 +18V +IN R5 100 C3 47F R3 6.8k 1% R4 6.8k 1% R1 10k Z1 Z2 C4 200pF R2 10k RG1 RG SSM2019 VOUT RG2 Z3 Z4 –IN –18V C2 C1, C2: 22F TO 47F, 63V, TANTALUM OR ELECTROLYTIC Z1–Z4: 12V, 1/2W Figure 4. SSM2019 in Phantom Powered Microphone Circuit REV. A –7– SSM2019 critical, then the servo loop can be replaced by the diode biasing scheme of Figure 5. If ac coupling is used throughout, then Pins 2 and 3 may be directly grounded. BUS SUMMING AMPLIFIER In addition to its use as a microphone preamplifier, the SSM2019 can be used as a very low noise summing amplifier. Such a circuit is particularly useful when many medium impedance outputs are summed together to produce a high effective noise gain. The principle of the summing amplifier is to ground the SSM2019 inputs. Under these conditions, Pins 1 and 8 are ac virtual grounds sitting about 0.55 V below ground. To remove the 0.55 V offset, the circuit of Figure 5 is recommended. + IN SSM2019 VOUT – IN R2 6.2k A2 forms a “servo” amplifier feeding the SSM2019 inputs. This places Pins l and 8 at a true dc virtual ground. R4 in conjunction with C2 removes the voltage noise of A2, and in fact just about any operational amplifier will work well here since it is removed from the signal path. If the dc offset at Pins l and 8 is not too V C1 R3 0.33F 33k R5 10k R4 5.1k A2 C2 200F TO PINS 2 AND 3 IN4148 PRINTED IN U.S.A. Figure 5. Bus Summing Amplifier –8– REV. A SSM2019 OUTLINE DIMENSIONS 0.400 (10.16) 0.365 (9.27) 0.355 (9.02) 8 5 1 4 0.280 (7.11) 0.250 (6.35) 0.240 (6.10) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.100 (2.54) BSC 0.060 (1.52) MAX 0.210 (5.33) MAX 0.015 (0.38) MIN 0.150 (3.81) 0.130 (3.30) 0.115 (2.92) SEATING PLANE 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) 0.195 (4.95) 0.130 (3.30) 0.115 (2.92) 0.015 (0.38) GAUGE PLANE 0.014 (0.36) 0.010 (0.25) 0.008 (0.20) 0.430 (10.92) MAX 0.005 (0.13) MIN 0.070 (1.78) 0.060 (1.52) 0.045 (1.14) 070606-A COMPLIANT TO JEDEC STANDARDS MS-001 CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. CORNER LEADS MAY BE CONFIGURED AS WHOLE OR HALF LEADS. Figure 6. 8-Lead Plastic Dual In-Line Package [PDIP] Narrow Body (N-8) Dimensions shown in inches and (millimeters) 10.50 (0.4134) 10.10 (0.3976) 9 16 7.60 (0.2992) 7.40 (0.2913) 8 1.27 (0.0500) BSC 0.30 (0.0118) 0.10 (0.0039) COPLANARITY 0.10 0.51 (0.0201) 0.31 (0.0122) 10.65 (0.4193) 10.00 (0.3937) 2.65 (0.1043) 2.35 (0.0925) SEATING PLANE 0.75 (0.0295) 45° 0.25 (0.0098) 8° 0° 0.33 (0.0130) 0.20 (0.0079) COMPLIANT TO JEDEC STANDARDS MS-013-AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. Figure 7. 16-Lead Standard Small Outline Package [SOIC_W] Wide Body (RW-16) Dimensions shown in millimeters and (inches) REV. A –9– 1.27 (0.0500) 0.40 (0.0157) 03-27-2007-B 1 SSM2019 5.00 (0.1968) 4.80 (0.1890) 1 5 4 6.20 (0.2441) 5.80 (0.2284) 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) 0.50 (0.0196) 0.25 (0.0099) 45° 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MS-012-AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 012407-A 8 4.00 (0.1574) 3.80 (0.1497) Figure 8. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (RN-8) Dimensions shown in millimeters and (inches) ORDERING GUIDE Model1 SSM2019BNZ SSM2019BRNZ SSM2019BRNZRL SSM2019BRWZ SSM2019BRWZRL 1 Temperature Range −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C −40°C to +85°C Package Description 8-Lead PDIP 8-Lead SOIC_N 8-Lead SOIC_N, REEL 16-Lead SOIC_W 16-Lead SOIC_W, REEL Package Option N-8 R-8 R-8 RW-16 RW-16 Z = RoHS Compliant Part REVISION HISTORY 6/11—Rev. 0 to Rev. A Updated Outline Dimensions ......................................................... 9 Changes to Ordering Guide .......................................................... 10 2/03—Revision 0: Initial Version ©2003–2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D02718-0-6/11(A) –10– REV. A