Self-Contained Audio Preamplifier SSM2017 - …

1 ASelf-ContainedAudio PreamplifierSSM2017 One Technology Way, Box 9106, Norwood, MA 02062-9106, : 617/329-4700 Fax: 617/326-8703 FUNCTIONAL BLOCK DIAGRAM+IN INOUT 5k REFERENCERG1 SSM2017V+X1RG2V X1V 5k 5k 5k 5k 5k PIN CONNECTIONSE poxy Mini-DIP (P Suffix)REFERENCE12348765 TOP VIEW(Not to Scale) IN+INV V+OUTRG2RG1 SSM201716-Pin Wide Body SOL (S Suffix)12345678 TOP VIEW(Not to Scale)161514131211109 NCNC IN+INV V+OUTREFERENCENCNCNCNCRG1RG2 NCNCSSM2017NC = NO CONNECTTOP VIEW(Not to Scale)FEATURESE xcellent Noise Performance: 950 pV/ Hz or dBNoise FigureUltralow THD: < @ G = 100 Over the Full AudioBandWide Bandwidth: 1 MHz @ G = 100 High Slew Rate: 17 V/ms typUnity Gain StableTrue Differential InputsSubaudio 1/f Noise Corner8-Pin Mini-DIP with Only One External ComponentRequiredVery Low CostExtended Temperature Range: 408C to +858 CAPPLICATIONSA udio Mix ConsolesIntercom/Paging SystemsTwo-Way RadioSonarDigital Audio SystemsGENERAL DESCRIPTIONThe SSM2017 is a latest generation Audio Preamplifier combin-ing SSM Preamplifier design expertise with advanced process-ing.

2 The result is excellent Audio performance from a Self-Contained 8-pin mini-DIP device, requiring only one externalgain set resistor or potentiometer. The SSM2017 is further en-hanced by its unity gain specifications include ultralow noise ( dB noise figure)and THD (< at G = 100), complemented by wide band-width and high slew for this low cost device include microphone pream-plifiers and bus summing amplifiers in professional and con-sumer Audio equipment, sonar, and other applications requiringa low noise instrumentation amplifier with high gain BInformation furnished by Analog Devices is believed to be accurate andreliable. However, no responsibility is assumed by Analog Devices for itsuse, nor for any infringements of patents or other rights of third partieswhich may result from its use.

3 No license is granted by implication orotherwise under any patent or patent rights of Analog SPECIFICATIONS(VS = 615 V and 408C TA +858C, unless otherwise noted. Typical speci-fications apply at TA = +258C.)ParameterSymbolConditionsMinTypMa xUnitsDISTORTION PERFORMANCETA = +25 CVO = 7 V rmsRL = 5 k Total Harmonic Distortion Plus NoiseTHD+NG = 1000, f = 1 = 100, f = 1 = 10, f = 1 = 1, f = 1 PERFORMANCEI nput Referred Voltage Noise Densityenf = 1 kHz, G = Hzf = 1 kHz; G = Hzf = 1 kHz; G = Hzf = 1 kHz; G = HzInput Current Noise Densityinf = 1 kHz, G = 10002pA/ HzDYNAMIC RESPONSESlew RateSRG = 101017V/ sRL = k CL = 50 pFTA = +25 CSmall Signal BandwidthBW 3 dBG = 1000200kHzG = 1001000kHzG = 102000kHzG = 14000kHzINPUTI nput Offset Bias CurrentIBVCM = 0 V625 AInput Offset CurrentIosVCM = 0 V ACommon-Mode RejectionCMRVCM = 8 VG = 100080112dBG = 1006092dBG = 104074dBG = 1, TA = +25 C2654dBG = 1, TA = 40 C to +85 C2054dBPower Supply RejectionPSRVS = 6 V to 18 VG = 100080124dBG = 10060118dBG = 1040101dBG = 12682dBInput Voltage RangeIVR 8 VInput ResistanceRIND ifferential, G = 10001M G = 130M Common Mode, G = G = OUTPUTO utput Voltage SwingVORL = 2 k.

4 TA = +25 C Offset VoltageVOOS 40500mVMinimum Resistive Load DriveTA = +25 C2k TA = 40 C to +85 Maximum Capacitive Load Drive50pFShort Circuit Current LimitISCO utput-to-Ground Short 50mAOutput Short Circuit Duration10secGAINGain AccuracyRG = 10 k TA = +25 C G 1RG = 10 , G = = 101 , G = = k , G = = `, G = GainG70dBREFERENCE INPUTI nput Resistance10k Voltage Range 8 VGain to Output1V/VPOWER SUPPLYS upply Voltage RangeVS 6 22 VSupply CurrentISYVCM = 0 V, RL = ` subject to change without B 2 OBSOLETESSM2017 3 REV. BWARNING!ESD SENSITIVE DEVICECAUTIONESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readilyaccumulate on the human body and test equipment and can discharge without the SSM2017 features proprietary ESD protection circuitry, permanent damage mayoccur on devices subjected to high energy electrostatic discharges.

5 Therefore, proper ESDprecautions are recommended to avoid performance degradation or loss of Performance CharacteristicsFigure 1. Typical THD+Noise* at G = 1, 10, 100, 1000;VO = 7 VRMS, VS = 15 V, RL = 5 k ; TA = +25 C*80 kHz low-pass filter used for Figures MAXIMUM RATINGSS upply Voltage .. 22 VInput Voltage .. Supply VoltageOutput Short Circuit Duration .. 10 secStorage Temperature Range (P, Z Packages) 65 C to +150 CJunction Temperature (TJ) .. 65 C to +150 CLead Temperature Range (Soldering, 60 sec) .. 300 COperating Temperature Range .. 40 C to +85 CThermal Resistance*8-Pin Hermetic DIP (Z): JA = 134; JC = 12 .. C/W8-Pin Plastic DIP (P): JA = 96; JC = 37 .. C/W16-Pin SOIC (S): JA = 92; JC = 27 .. C/W* JA is specified for worst case mounting conditions, , JA is specified for devicein socket for cerdip and plastic DIP; JA is specified for device soldered to printedcircuit board for SOL GUIDET emperaturePackagePackageModelRange*Descr iptionOptionSSM2017P 40 C to +85 C8-Pin Plastic DIPN-8 SSM2017S 40 C to +85 C16-Lead SOLR-16 SSM2017S-REEL 40 C to +85 C16-Lead SOLR-16*XIND = 40 C to +85 2.

6 Typical THD+ Noise * at G = 2, 10, 100, 1000;VO = 10 VRMS, VS = 18 V, RL = 5 k ; TA = +25 COBSOLETESSM2017 4 REV. BFigure 3. Voltage Noise Density 6. Maximum Output Swingvs. FrequencyFigure 9. Output Voltage Range VoltageFigure 4. RTI Voltage Noise Densityvs. GainFigure 7. Maximum Output Voltagevs. Load ResistanceFigure 10. CMRR vs. FrequencyFigure 5. Output Impedance 8. Input Voltage Range VoltageFigure 11. +PSRR vs. FrequencyOBSOLETESSM2017 5 REV. BFigure 12. PSRR vs. FrequencyFigure 15. VOOS vs. TemperatureFigure 18. IB vs. Supply VoltageFigure 13. VIOS vs. TemperatureFigure 16. VOOS vs. Supply VoltageFigure 19. ISY vs. TemperatureFigure 14. VIOS vs. Supply VoltageFigure 17. IB vs. TemperatureFigure 20. ISY VoltageOBSOLETESSM2017 6 REV. BFigure 21. Bandwidth of the SSM2017 for Various Valuesof GainNOISE PERFORMANCEThe SSM2017 is a very low noise Audio Preamplifier exhibitinga typical voltage noise density of only 1 nV/ Hz at 1 kHz.

7 Theexceptionally low noise characteristics of the SSM2017 are inpart achieved by operating the input transistors at high collectorcurrents since the voltage noise is inversely proportional to thesquare root of the collector current. Current noise, however, isdirectly proportional to the square root of the collector a result, the outstanding voltage noise performance of theSSM2017 is obtained at the expense of current noise perfor-mance. At low Preamplifier gains, the effect of the SSM2017 svoltage and current noise is total noise of an Audio Preamplifier channel can be calcu-late by:En = en2+(inRS)2+et2where:En = total input referred noiseen = amplifier voltage noisein = amplifier current noiseRS = source resistanceet = source resistance thermal a microphone Preamplifier , using a typical microphone im-pedance of 150 the total input referred noise is.

8 En = 1 nV/ Hz @ 1 kHz, SSM2017 enin = 2 pA/ Hz @ 1 kHz, SSM2017 inRS = 150 , microphone source impedanceet = nV/ Hz @ 1 kHz, microphone thermal noiseEn = (1 nV Hz)2 + 2 (pA/ Hz 150 )2 + ( nV/ Hz)2= nV/ Hz @ 1 total noise is extremely low and makes the SSM2017virtually transparent to the = VOUT(+In) (In) = 10 kVRG +1 Basic Circuit ConnectionsGAINThe SSM2017 only requires a single external resistor to set thevoltage gain. The voltage gain, G, is:G = 10k RG+1andRG = 10k G 1 For convenience, Table I lists various values of RG for commongain I. Values of RG for Various Gain LevelsThe voltage gain can range from 1 to 3500. A gain set resistor isnot required for unity gain applications. Metal-film or wire-wound resistors are recommended for best total gain accuracy of the SSM2017 is determined by thetolerance of the external gain set resistor, RG, combined with thegain equation accuracy of the SSM2017 .

9 Total gain drift com-bines the mismatch of the external gain set resistor drift withthat of the internal resistors (20 ppm/ C typ).Bandwidth of the SSM2017 is relatively independent of gain asshown in Figure 21. For a voltage gain of 1000, the SSM2017has a small-signal bandwidth of 200 kHz. At unity gain, thebandwidth of the SSM2017 exceeds 4 7 REV. BFigure 23. SSM2017 in Phantom Powered Microphone CircuitINPUTSThe SSM2017 has protection diodes across the base emitterjunctions of the input transistors. These prevent accidental ava-lanche breakdown which could seriously degrade noise perfor-mance. Additional clamp diodes are also provided to prevent theinputs from being forced too far beyond the Single Endedb. Pseudo Differentialc. True DifferentialFigure 22. Three Ways of Interfacing Transducers for HighNoise ImmunityAlthough the SSM2017 s inputs are fully floating, care must beexercised to ensure that both inputs have a dc bias connectioncapable of maintaining them within the input common-moderange.

10 The usual method of achieving this is to ground one sideof the transducer as in Figure 22a, but an alternative way is tofloat the transducer and use two resistors to set the bias point asin Figure 22b. The value of these resistors can be up to 10 k ,but they should be kept as small as possible to limit common-mode pickup. Noise contribution by resistors themselves is neg-ligible since it is attenuated by the transducer s impedance. Bal-anced transducers give the best noise immunity and interfacedirectly as in Figure TERMINALThe output signal is specified with respect to the reference ter-minal, which is normally connected to analog ground. The ref-erence may also be used for offset correction or level shifting. Areference source resistance will reduce the common-mode rejec-tion by the ratio of 5 k /RREF.