Low Cost Quad Voltage Controlled Amplifier

a FEATURES Four High Performance VCAs in a Single Package 0.02% THD No External Trimming 120 dB Gain Range 0.07 dB Gain Matching (Unity Gain) Class A or AB Operation APPLICATIONS Remote, Automatic, or Computer Volume Controls Automotive Volume/Balance/Faders Audio Mixers Compressor/Limiters/Compandors Noise Reduction Systems Automatic Gain Controls Voltage Controlled Filters Spatial Sound Processors Effects Processors GENERAL DESCRIPTION Low Cost Quad Voltage Controlled Amplifier SSM2164 FUNCTIONAL BLOCK DIAGRAM VC IIN VCA1 IIOUT VC IIN VCA2 IIOUT VC The SSM2164 contains four independent voltage controlled amplifiers (VCAs) in a single package. High performance (100 dB dynamic range, 0.02% THD) is provided at a very low cost-per-VCA, resulting in excellent value for cost sensitive gain control applications. Each VCA offers current input and output for maximum design flexibility, and a ground referenced –33 mV/dB control port. All channels are closely matched to within 0.07 dB at unity gain, and 0.24 dB at 40 dB of attenuation. A 120 dB gain range is possible. A single resistor tailors operation between full Class A and AB modes. The pinout allows upgrading of SSM2024 designs with minimal additional circuitry. The SSM2164 will operate over a wide supply voltage range of ± 4 V to ± 18 V. Available in 16-pin P-DIP and SOIC packages, the device is guaranteed for operation over the extended industrial temperature range of –40°C to +85°C. IIN VCA3 IIOUT VC IIN VCA4 IIOUT POWER SUPPLY AND BIASING CIRCUITRY V+ GND V– MODE 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 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 Fax: 617/326-8703 SSM2164–SPECIFICATIONS ELECTRICAL SPECIFICATIONS (V = ±15 V, A = 0 dB, 0 dBu = 0.775 V rms, V Parameter AUDIO SIGNAL PATH Noise Headroom Total Harmonic Distortion Conditions VIN = GND, 20 kHz Bandwidth Clip Point = 1% THD+N 2nd and 3rd Harmonics Only AV = 0 dB, Class A AV = ± 20 dB, Class A1 AV = 0 dB, Class AB AV = ± 20 dB, Class AB1 CF = 10 pF CF = 10 pF VIN = 0 S V IN = 0 dBu, RIN = ROUT = 30 kΩ, f = 1 kHz, –40°C < TA < +85°C using Typical Application Circuit (Class AB), unless otherwise noted. Typical specifications apply at TA = +25°C.) Min SSM2164 Typ Max –94 22 0.02 0.15 0.16 0.3 –110 500 0.7 ± 10 ± 50 ± 0.1 5 –33 –3300 1.5 0.07 0.24 –100 +20 .1 Units dBu dBu % % % % dB kHz mA/µs nA nA V kΩ mV/dB ppm/°C mV dB dB dB dB V mA dB Channel Separation Unity Gain Bandwidth Slew Rate Input Bias Current Output Offset Current Output Compliance CONTROL PORT Input Impedance Gain Constant Gain Constant Temperature Coefficient Control Feedthrough Gain Matching, Channel-to-Channel Maximum Attenuation Maximum Gain POWER SUPPLIES Supply Voltage Range Supply Current Power Supply Rejection Ratio NOTES 1 –10 dBu input @ 20 dB gain; +10 dBu input @ –20 dB gain. 2 After 60 seconds operation. 3 +25°C to +85°C. Specifications subject to change without notice. (Note 2) 0 dB to –40 dB Gain Range3 AV = 0 dB AV = –40 dB 8.5 ±4 Class AB 60 Hz 6 90 ± 18 8 TYPICAL APPLICATION AND TEST CIRCUIT VC VC4 100pF 14 IIN 30kΩ VIN4 500Ω 560pF 15 13 IIOUT VCA4 30kΩ 1/2 OP275 VOUT4 POWER SUPPLY AND BIASING CIRCUITRY 9 V– 8 16 GND V+ 1 MODE RB (7.5kΩ CLASS A) (OPEN CLASS AB) 0.1µF 0.1µF –15V +15V Figure 1. RIN = ROUT = 30 kΩ, CF = 100 pF. Optional RB = 7.5 kΩ, Biases Gain Core to Class A Operation. For Class AB, Omit RB. –2– REV. 0 SSM2164 ABSOLUTE MAXIMUM RATINGS Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V Input, Output, Control Voltages . . . . . . . . . . . . . . . . V– to V+ Output Short Circuit Duration to GND . . . . . . . . . Indefinite Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C Operating Temperature Range . . . . . . . . . . . . . –40°C to +85°C Junction Temperature Range . . . . . . . . . . . . –65°C to +150°C Lead Temperature Range (Soldering 60 sec) . . . . . . . . +300°C Package Type 16-Pin Plastic DIP (P Suffix) 16-Pin SOIC (S Suffix) θJA* 76 92 θJC 33 27 Units °C/W °C/W ORDERING GUIDE Model SSM2164P SSM2164S Temperature Range –40°C to +85°C –40°C to +85°C Package Description Plastic DIP Narrow SOIC Package Options N-16 R-16A PIN CONFIGURATION 16-Lead Epoxy DIP and SOIC *θJA is specified for the worst case conditions; i.e., θJA is specified for device in socket for P-DIP packages, θJA is specified for device soldered in circuit board for SOIC package. MODE IIN1 VC1 IOUT1 IOUT2 VC2 IIN2 GND 1 2 3 4 5 6 7 8 16 V+ 15 IIN4 14 VC4 SSM2164 13 IOUT4 TOP VIEW 12 IOUT3 (Not to Scale) 11 VC3 10 IIN3 9 V– 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 SSM2164 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. 0 –3– SSM2164 Typical Performance Characteristics 1.0 CLASS A VS = ±15V LPF = 80kHz THD + N – % AV = + 20dB 0.1 AV = – 20dB AV = 0dB 0.01 20 100 1k FREQUENCY – Hz 10k 20k 210 200 190 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 0.00 0.05 0.10 0.15 0.20 0.25 THD – % VS = ±15V TA = +25°C 1200 CHANNELS UNITS 0.30 0.35 0.40 0.45 Figure 2. THD+N vs. Frequency, Class A Figure 5. THD Distribution, Class AB 1.0 CLASS AB VS = ±15V LPF = 80kHz AV = +20dB THD + N – % AV = –20dB 1.0 VS ±15V AV = 0dB LPF = 22kHz THD + N – % 0.1 AV = 0dB CLASS AB 0.1 CLASS A 0.01 20 100 1k FREQUENCY – Hz 10k 20k 0.01 20 100 1k AMPLITUDE – VRMS 10k 20k Figure 3. THD+N vs. Frequency Class, AB Figure 6. THD+N vs. Amplitude 300 280 260 240 220 200 VS = ±15V TA = +25°C 1200 CHANNELS 0.10 LPF = 80kHz 0.08 THD + N – % 180 UNITS 0.06 160 140 120 100 80 60 40 20 0 0.005 0.010 0.04 0.02 0 0.015 0.020 0.025 0.030 THD – % 0.035 0.040 0.045 0.050 0 ±4 ±8 ±12 ±16 ±20 SUPPLY – Volts Figure 4. THD Distribution, Class A Figure 7. THD+N vs. Supply Voltage, Class A –4– REV. 0 SSM2164 1000 0.030 0.025 % THD VOLTAGE NOISE DENSITY – nV/ VS = ±15V VIN = 0dBu AV = 0dB VS = ±15V TA = +25°C Hz 100 10 0.020 0.015 0.010 –40 –20 0 20 40 TEMPERATURE – °C 60 80 1k 10k RBIAS – Ω 100k 1M Figure 8. THD vs. Temperature, Class A Figure 11. Voltage Noise Density vs. RBIAS 1.0 0.30 VS = ±15V VIN = 0dBu AV = 0dB VS = ±15V TA = +25°C 0.25 % THD 0.20 THD – % –40 –20 0 20 40 TEMPERATURE – °C 60 80 0.1 0.15 0.10 0.01 1k 10k RBIAS – Ω 100k 1M Figure 9. THD vs. Temperature, Class AB 500 VS = ±15V RIN = RF = 30kΩ TA = +25°C 10 Figure 12. THD vs. RBIAS CONTROL FEEDTHROUGH – mV 400 5 VS = ±15V TA = +25°C Hz 0 300 NOISE – nV/ –5 200 –10 100 –15 0 1 10 100 1k FREQUENCY – Hz 10k 100k –20 1k 10k RBIAS – Ω 100k 1M Figure 10. Voltage Noise Density vs. Frequency, Class AB Figure 13. Control Feedthrough vs. RBIAS REV. 0 –5– SSM2164 Typical Performance Characteristics 15 PHASE 10 VS = ±15V TA = +25°C AV = 0dB CF = 10pF GAIN 0 0 180 –3dB BANDWIDTH – Hz 10M VS = ±15V TA = +25°C 1M PHASE – Degrees 5 90 GAIN – dB –5 –90 100k –10 –180 –15 1k 10k 100k FREQUENCY – Hz 1M 10M 10k 1 10 100 1000 I TO V FEEDBACK CAPACITOR – pF Figure 14. Gain/Phase vs. Frequency 0.1 CF = 10pF 0 Figure 17. –3 dB Bandwidth vs. I-to-V Feedback Capacitor 30 ±SLEW RATE VS = ±15V TA = +25°C 25 CF = 100pF GAIN – dB –0.1 VS = ±15V TA = +25°C AV = 0dB SLEW RATE – V/µs 20 OP275 OUTPUT AMPLIFIER 15 –0.2 10 –0.3 5 –0.4 10 100 1k FREQUENCY – Hz 10k 100k 0 1 10 I TO V FEEDBACK CAPACITOR – pF 100 Figure 15. Gain Flatness vs. Frequency Figure 18. Slew Rate vs. I-to-V Feedback Capacitor 40 VS = ±15V TA = +25°C CF = 10pF 20 VS = ±15V TA = +25°C VIN = 0V RF = RIN = 30kΩ AV = 0dB 0 CONTROL FEEDTHROUGH – dB 20 AV = +20dB 0 GAIN – dB –20 AV = –20dB –20 –40 –40 –60 –60 100 1k 10k 100k FREQUENCY – Hz 1M 10M –80 100 1k 10k FREQUENCY – Hz 100k 1M Figure 16. Bandwidth vs. Gain Figure 19. Control Feedthrough vs. Frequency –6– REV. 0 SSM2164 0 APPLICATIONS INFORMATION Circuit Description VS = ±15V TA = +25°C –20 PSRR – dB –40 +PSRR –60 –PSRR –80 The SSM2164 is a quad Voltage Controlled Amplifier (VCA) with 120 dB of gain control range. Each VCA is a current-in, current-out device with a separate –33 mV/dB voltage input control port. The class of operation (either Class A or Class AB) is set by a single external resistor allowing optimization of the distortion versus noise tradeoff for a particular application. The four independent VCAs in a single 16-pin package make the SSM2164 ideal for applications where multiple volume control elements are needed. V+ –100 10 100 1k 10k FREQUENCY – Hz 100K 1M Figure 20. PSRR vs. Frequency IIN 25 VS = ±15V TA = +25°C Q5 Q6 Q7 Q8 20 IOUT MODE 4.5kΩ Q1 Q2 Q3 Q4 450Ω 500Ω VC SUPPLY CURRENT – mA +ISY 15 –ISY 10 5 0 1k 10k RBIAS – Ω 100k 1M V– Figure 23. Simplified Schematic (One Channel) Figure 21. Supply Current vs. RBIAS –45 CLASS A AND CLASS AB –40 GAIN CONSTANT – mV/dB VS = ±15V –35 The simplified schematic in Figure 23 shows the basic structure of