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: -40 C to +85 C APPLICATIONS Audio Mix Consoles Intercom/Paging Systems 2-Way Radio Sonar Digital Audio Systems Self-Contained Audio Preamplifier SSM2019 FUNCTIONAL BLOCK DIAGRAM V+ V- +IN -IN RG1 RG2 5k 5k 5k REFERENCE V- 5k 1 5k 5k 1 OUT PIN CONNECTIONS 8-Lead PDIP (N Suffix) 8-Lead Narrow Body SOIC (RN Suffix)* 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. RG1 1 -IN 2 8 RG2 V+ TOP VIEW +IN 3 (Not to Scale) 6 OUT 7 SSM2019 V- 4 5 REFERENCE 16-Lead Wide Body SOIC (RW Suffix) NC 1 RG1 2 NC 3 -IN 4 16 NC 15 RG2 14 NC 13 V+ TOP VIEW +IN 5 (Not to Scale) 12 NC SSM2019 NC 6 V- 7 NC 8 11 OUT 10 REFERENCE 9 NC NC = NO CONNECT *Consult factory for availability. REV. 0 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: 781/326-8703 (c) 2003 Analog Devices, Inc. All rights reserved. -40 SSM2019-SPECIFICATIONS (V = at15 V=and C.) C T +85 C, unless otherwise noted. Typical specifications apply T 25 S A A Parameter DISTORTION PERFORMANCE Total Harmonic Distortion Plus Noise Symbol Conditions 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 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 = 2 kW CL = 100 pF G = 1000 G = 100 G = 10 G=1 Min Typ Max Unit THD + N 0.017 0.0085 0.0035 0.005 % % % % NOISE PERFORMANCE Input Referred Voltage Noise Density en Input Current Noise Density DYNAMIC RESPONSE Slew Rate Small Signal Bandwidth in SR BW-3 dB 1.0 1.7 7 50 2 16 200 1000 1600 2000 0.05 0.25 3 10 0.001 1.0 110 90 70 50 110 110 90 70 12 130 113 94 74 124 118 101 82 1 30 5.3 7.1 13.9 4 30 5000 50 Continuous nV//Hz nV//Hz nV//Hz nV//Hz pA//Hz V/ms kHz kHz kHz kHz mV mA mA dB dB dB dB dB dB dB dB V MW MW MW MW V mV 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 = 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 RL = 2 kW, TA = 25C Output-to-Ground Short Input Voltage Range Input Resistance IVR RIN OUTPUT Output Voltage Swing Output Offset Voltage Maximum Capacitive Load Drive Short Circuit Current Limit Output Short Circuit Duration GAIN Gain Accuracy VO VOOS ISC 13.5 RG = 10 kW G-1 TA = 25C RG = 10 W, G = 1000 RG = 101 W, G = 100 RG = 1.1 kW, G = 10 RG = , G = 1 0.5 0.5 0.5 0.1 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 0.1 0.2 0.2 0.2 70 10 12 1 dB dB dB dB dB kW V V/V 18 7.5 8.5 V mA mA VS ISY VCM = 0 V, RL = VCM = 0 V, VS = 18 V, RL = 5 4.6 4.7 -2- REV. 0 SSM2019 Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Voltage Output Short Circuit Duration . . . . . . . . . . . . . . . . . . . 10 sec Storage Temperature Range . . . . . . . . . . . . -65C to +150C Junction Temperature (TJ) . . . . . . . . . . . . . -65C to +150C Lead Temperature Range (Soldering, 60 sec) . . . . . . . . 300C Operating Temperature Range . . . . . . . . . . . -40C to +85C Thermal Resistance2 8-Lead PDIP (N) . . . . . . . . . . . . . . . . . . . . . . . JA = 96C/W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JC = 37C/W 16-Lead SOIC (RW) . . . . . . . . . . . . . . . . . . . . JA = 92C/W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . JC = 27C/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 ABSOLUTE MAXIMUM RATINGS 1 ORDERING GUIDE Model SSM2019BN SSM2019BRW SSM2019BRWRL SSM2019BRN* SSM2019BRNRL* Temperature Range -40C to +85C -40C to +85C -40C to +85C -40C to +85C -40C to +85C Package Description 8-Lead PDIP 16-Lead SOIC 16-Lead SOIC, Reel 8-Lead SOIC 8-Lead SOIC, Reel Package Option N-8 RW-16 RW-16 RN-8 RN-8 *Consult factory for availability. 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 0.1 100 G = 1000 0.01 G = 100 G=1 G = 10 RTI, VOLTAGE NOISE DENSITY - nV/ Hz TA = 25 C VS = 15V G = 1000 10 THD + N - % 0.001 15V VS 7Vrms VO RL 600 BW = 80kHz 0.0001 10 20 18V 10Vrms 1 0.1 1k FREQUENCY - Hz 10k 20k 100 1 10 100 FREQUENCY - Hz 1k 10k TPC 1. Typical THD + Noise vs. Gain TPC 2. Voltage Noise Density vs. Frequency REV. 0 -3- SSM2019 100 RTI VOLTAGE NOISE DENSITY - nV/ Hz TA = 25 C VS = 15V 100 90 PEAK-TO-PEAK VOLTAGE - V 30 GAIN 25 10 80 10 IMPEDANCE - GAIN = 1 70 60 50 40 30 20 10 f = 1kHz OR 10kHz 20 1 TA = 25 C RL = 2k VS = 15V 15 0.1 1 10 GAIN 100 1k 0 100 1k 10k 100k FREQUENCY - Hz 1M 10 100 1k 10k 100k FREQUENCY - Hz 1M TPC 3. RTI Voltage Noise Density vs. Gain TPC 4. Output Impedance vs. Frequency TPC 5. Maximum Output Swing vs. Frequency 16 OUTPUT VOLTAGE - V 12 10 8 6 4 2 0 10 G=1 OUTPUT SWING (VOUT+ - VOUT-) - V TA = 25 C 14 VS = 15V 40 G 10 20 TA = 25 C f = 100kHz TA = 25 C INPUT SWING (VIN+ - VIN-) - V 30 15 20 10 10 5 1k 10k 100 LOAD RESISTANCE - 100k 0 0 10 20 30 40 SUPPLY VOLTAGE (V+ - V-) - V 0 0 10 30 20 SUPPLY VOLTAGE (V+ - V-) - V 40 TPC 6. Output Voltage vs. Load Resistance TPC 7. Input Voltage Range vs. Supply Voltage TPC 8. Output Voltage Range vs. Supply Voltage 200 VCM = 100mV 180 VS = 15V TA = 25 C 160 140 G = 1000 G = 100 G = 10 G=1 150 G = 1000 125 G = 10 100 +PSRR - dB 150 G = 1000 125 G = 100 G = 10 100 -PSRR - dB G = 100 CMRR - dB G=1 120 100 80 60 40 20 0 10 75 G=1 50 VCM = 100mV TA = 25 C VS = 15V 100 1k 10k FREQUENCY - Hz 100k 75 50 VS = 100mV TA = 25 C VS = 15V 100 1k 10k FREQUENCY - Hz 100k 25 25 100 1k 10k 100k 0 10 0 10 FREQUENCY- Hz TPC 9. CMRR vs. Frequency TPC 10. Positive PSRR vs. Frequency TPC 11. Negative PSRR vs. Frequency -4- REV. 0 SSM2019 0.040 V+/V- = 0.035 0.030 15V 0.02 TA = 25 C 0.01 0 0 V+/V- = -1 -2 15V 0.020 0.015 0.010 0.005 0 -50 VOOS - mV 0 5 10 15 20 25 30 35 SUPPLY VOLTAGE (VCC - VEE) - V 40 VIOS - mV VIOS - mV 0.025 -0.01 -0.02 -0.03 -0.04 -0.05 -3 -4 -5 -6 -7 -8 -50 -25 0 25 50 TEMPERATURE - C 75 100 -0.06 -25 25 0 50 TEMPERATURE - C 75 100 TPC 12. VIOS vs. Temperature TPC 13. VIOS vs. Supply Voltage TPC 14. VOOS vs. Temperature 30 TA = 25 C 20 5 V+/V- = 4 15V 6 TA = 25 C 5 10 VOOS - mV 4 IB - A IB+ OR IB- 2 IB - A 3 0 3 -10 1 2 -20 0 -50 1 -30 0 5 10 15 20 25 30 35 SUPPLY VOLTAGE (VCC - VEE) - V 40 0 -25 0 25 50 TEMPERATURE - C 75 100 0 10 20 30 SUPPLY VOLTAGE (VCC - VEE) - V 40 TPC 15. VOOS vs. Supply Voltage TPC 16. IB vs. Temperature TPC 17. IB vs. Supply Voltage 8 6 I+ @ V+/V- = SUPPLY CURRENT - mA 8 TA = 25 C 6 18V SUPPLY CURRENT - mA 4 2 0 -2 -4 -6 -8 -25 0 25 50 TEMPERATURE - C 75 100 I- 15V I+ SUPPLY CURRENT - mA 16 TA = 25 C 14 12 10 8 6 4 2 4 I+ @ V+/V- = 2 0 -2 -4 -6 -8 -50 I- @ V+/V- = I- @ V+/V- = 18V 15V 0 5 10 15 20 25 30 35 40 0 0 10 15 5 SUPPLY VOLTAGE - V 20 SUPPLY VOLTAGE (VCC - VEE) - V TPC 18. Supply Current vs. Temperature TPC 19. Supply Current vs. Supply Voltage TPC 20. ISY vs. Supply Voltage REV. 0 -5- SSM2019 V+ VS = 15V TA = 25 C +IN RG SSM2019 RG2 OUT REFERENCE -IN VOLTAGE GAIN - dB RG1 60 40 20 0 G= VOUT (+IN) - (- IN) = 10k RG +1 V- Figure 1. Basic Circuit Connections GAIN The SSM2019 only requires a single external resistor to set the voltage gain. The voltage gain, G, is: G= 10 kW +1 RG 10 kW G -1 1k 10k 100k 1M 10M Figure 2. Bandwidth for Various Values of Gain NOISE PERFORMANCE and the external gain resistor, RG , is: RG = For convenience, Table I lists various values of RG for common gain levels. Table I. Values of RG for Various Gain Levels RG ( ) AV NC 4.7 k 1.1 k 330 100 32 10 1 3.2 10 31.3 100 314 1000 dB 0 10 20 30 40 50 60 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. 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 RS = source resistance et = source resistance thermal noise For a microphone preamplifier, using a typical microphone impedance of 150 W, the total input referred noise is: E n = (1 nV Hz )2 + 2( pA / Hz 150 W)2 + (1.6 nV / Hz )2 = 1.93 nV / Hz @ 1 kHz 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. 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). 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. 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. 0 SSM2019 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) TRANSDUCER (NONINVERTING) 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. 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. REFERENCE TERMINAL a. Single-Ended R TRANSDUCER R SSM2019 b. Pseudo-Differential 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). COMMON-MODE REJECTION TRANSDUCER SSM2019 c. True Differential Figure 3. Three Ways of Interfacing Transducers for High Noise Immunity 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. 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 +IN R3 6.8k 1% R1 10k Z1 Z2 Z3 Z4 C4 200pF +18V R5 100 RG1 RG SSM2019 RG2 VOUT C3 47 F -IN R4 6.8k 1% C2 R2 10k -18V C1, C2: 22 F TO 47 F, 63V, TANTALUM OR ELECTROLYTIC Z1-Z4: 12V, 1/2W Figure 4. SSM2019 in Phantom Powered Microphone Circuit REV. 0 -7- SSM2019 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. 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 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. + IN - IN R2 6.2k C1 R3 0.33 F 33k R4 5.1k A2 C2 200 F TO PINS 2 AND 3 IN4148 V R5 10k Figure 5. Bus Summing Amplifier OUTLINE DIMENSIONS 8-Lead Plastic Dual In-Line Package [PDIP] (N-8) Dimensions shown in inches and (millimeters) 0.375 (9.53) 0.365 (9.27) 0.355 (9.02) 8 5 16-Lead Standard Small Outline Package [SOIC] Wide Body (RW-16) Dimensions shown in millimeters and (inches) 10.50 (0.4134) 10.10 (0.3976) 1 4 0.295 (7.49) 0.285 (7.24) 0.275 (6.98) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.015 (0.38) MIN SEATING PLANE 0.060 (1.52) 0.050 (1.27) 0.045 (1.14) 16 9 7.60 (0.2992) 7.40 (0.2913) 0.150 (3.81) 0.135 (3.43) 0.120 (3.05) 1 8 0.100 (2.54) BSC 0.180 (4.57) MAX 0.150 (3.81) 0.130 (3.30) 0.110 (2.79) 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) 10.65 (0.4193) 10.00 (0.3937) 0.015 (0.38) 0.010 (0.25) 0.008 (0.20) 1.27 (0.0500) BSC 0.30 (0.0118) 0.10 (0.0039) 0.51 (0.0201) 0.33 (0.0130) 2.65 (0.1043) 2.35 (0.0925) 0.75 (0.0295) 0.25 (0.0098) 45 COPLANARITY 0.10 SEATING PLANE 0.32 (0.0126) 0.23 (0.0091) 8 0 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MO-095AA 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 COMPLIANT TO JEDEC STANDARDS MS-013AA 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 8-Lead Standard Small Outline Package [SOIC]* Narrow Body (RN-8) Dimensions shown in millimeters and (inches) 5.00 (0.1968) 4.80 (0.1890) 8 5 4 4.00 (0.1574) 3.80 (0.1497) 1 6.20 (0.2440) 5.80 (0.2284) 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY SEATING 0.10 PLANE 1.75 (0.0688) 1.35 (0.0532) 8 0.25 (0.0098) 0 0.19 (0.0075) 0.50 (0.0196) 0.25 (0.0099) 45 0.51 (0.0201) 0.33 (0.0130) 1.27 (0.0500) 0.41 (0.0160) COMPLIANT TO JEDEC STANDARDS MS-012AA 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 *Consult factory for availability. -8- REV. 0 PRINTED IN U.S.A. C02718-0-2/03(0) SSM2019 VOUT