Iout 5. Iout 12. Iout 4. Iout 13

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Rafe Bennett
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1 1. Overview The V2164M/D contains four independent voltage controlled amplifiers(vcas) in a single package. High performance(1 db dynamic range,.2% THD) is provided at a very lowcostpervca, 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.. The V2164M/D will operate over a wide supply voltage range of ±4 V to ±18 V. Available in 16pin SOC packages, the device is guaranteed for operation over the extended industrial temperature range of 4 C to 85 C. The V2164M/D is available for many applications as 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. ts features are: Four High Performance VCAs in a Single Package.2% THD No External Trimming 12 db Gain Range.7 db Gain Matching (Unity Gain) Class A or AB Operation 2. Block Diagram and Pin Description 2.1 Block Diagram VCA1 VCA2 VCA3 VCA4 Biasing Circuitry Power Supply and MODE V GND V 3 2 N 6 7 N 11 1 N 14 N 2. 2 Pin Description Pin No. Symbol Function Pin No. Symbol Function 1 MODE Mode select 9 V negative power supply 2 N1 current input1 1 N3 current input 3 3 V C1 voltage controller 1 11 V C3 voltage controller 3 Page 1 of 1

2 4 OUT1 current output 1 12 OUT3 current output 3 5 OUT2 current output 2 13 OUT4 current output 4 6 V C2 voltage controller 2 14 V C4 voltage controller 4 7 N2 current input 2 N4 current input 4 8 GND GND 16 V positive power supply 3. Electrical Characteristics 3.1 Absolute Maximum Ratings Unless otherwise specified, T amb = 25 Parameter Symbol Value Unit Supply voltage c ±18 V input, output, control voltages Vin Vout VCA V ~ V V Output Short Circuit Duration to GND ndefinite S Storage Temperature Range Tstg 65~ Operating Temperature Range Topr 4~85 Junction Temperature Range Tj 65~ Lead Temperature Range (Soldering 6 sec) Electrical Characteristics Unless otherwise specified, T amb = 25,V CC =±V,A V =db,v N =dbμ,r N =R OUT =, f=1khz, using Typical Application Circuit (Class AB) Parameter Symbol Conditions Audio signal path Value Min Typ Max Noise V NO V N =GND,BW=2kHz 94 dbμ Headroom Hr Clip point=1%thdn 22 dbμ Total Harmonic Distortion (2nd and 3rd Harmonics Only) THD A V =db,class A.2.1 % A V =±2dB,Class A 1. % A V =db,class AB.16 % A V =±2dB,Class AB 1.3 % Channel Separation Sep 11 db Unity Gain Bandwidth GB C F =1pF 5 khz Slew Rate S R C F =1pF.7 ma/μs nput Bias Current B ±1 na Output Offset Current O V N = ±5 na Output Compliance V OD ±.1 V Control port nput mpedance Rin 5 kω Unit Page 2 of 1

3 Gain Constant G C (note 2) 33 mv/db Gain Constant Temperature G CT 33 ppm/ Coefficient Control Feedthrough V CF db to 4dB Gain Range mv Gain Matching, A V =db.7 db G M ChanneltoChannel A V =4dB.24 db Maximum Attenuation G A 1 db Maximum Gain G MAX 2 db Power supplies Supply Voltage Range V CC ±4 ±18 V Supply Current CCQ Class AB 6 8 ma Power Supply Rejection Ratio PSRR 6Hz 9 db Note:1,1 2 db gain,1 dbμ 2 db gain 2,After 6 seconds operation 3,25 to Test Circuit V C4 14 1pF 4 5Ω N VCA4 13 OUT 1/2 OP275 V OUT4 56pF Power Supply and Biasing Circuitry V GND V MODE Open Class AB (7.5kΩ Class A) V V Page 3 of 1

4 5. Characteristics Curve Units Ta= Channels THD% Figure 1 THD Distribution,Class AB THDN % 1..1 Class A LPF=8kHz Av=2dB Av=2dB Av=dB k 1k 2k Frequency Hz Figure 2 THDN vs. Frequency,Class A THDN % 1..1 Class AB LPF=8kHz Av=2dB Av=2dB Av=dB THDN % 1..1 Av=dB LPF=22kHz Class AB Class A Units THD% k 1k 2k Frequency Hz Figure 3 THDN vs. Frequency,Class AB Ta=25 12 Channels THD% Figure 5 THD Distribution,Class A Vin=dBu Av=dB THDN% k 1k 2k Amplitude Vrms Figure 4 THDN vs. Amplitude LPF=8kHz. ±4 ±8 ±12 ±16 ±2 Supply VoltageV Voltage Noise Density Figure 6 THDN vs. Supply Voltage,Class A 1 1 Ta= Temperature Figure 7 THD vs. Temperature, Class A 1 1k 1k RbiasΩ 1k 1M Figure 8 Voltage Noise Density vs. R BAS Page 4 of 1

5 .3 Vin=dBu Av=dB 1 THD% THD% 1 Ta= Temperature Figure 9 THD vs. temperature, Class AB 1 1k 1k RbiasΩ 1k 1M Figure 1 THD vs. R BAS ConrtolFeedthroughmV Ta=25 Noise Rin=Rf= Ta=25 2 1k 1k RbiasΩ 1k 1M Figure 11 Control Feedthrough vs. R BAS k 1k 1k FrequencyHz Figure 12 Voltage Noise Density vs. Frequency,Class AB 3dB BW Hz 1M Ta=25 1M 1k GaindB 1 Ta=25 5 Av=dB Cf=1pF 5 1 Phase Gain 1k to V feedback capacitorpf 1k 1k 1k 1M FrequencyHz 1M Figure 13 3 db Bandwidth vs. tov Feedback Capacitor Figure 14 Gain/Phase vs. Frequency Slew RateV/μS OP275 Output Amplifier ±Slew Rate Ta=25 GaindB.2 Ta=25.1 Av=dB.1.2 Cf=1pF Cf=1pF to V Feedback Capacitor pf Figure Slew Rate vs. tov Feedback Capacitor k 1k 1k FrequencyHz Figure 16 Gain Flatness vs. Frequency Page 5 of 1

6 GaindB 6 Ta=25 4 Cf=1pF Av=2dB Av=dB Av=2dB Control FeedthroughdB 4 Ta=25 2 Vin=V Rf=Rin= k 1k 1k FrequencyHz 1M 1M 8 1 1k 1k 1k FrequencyHz 1M Figure 17 Bandwidth vs. Gain Figure 18 Control Feedthrough vs. Frequency 2 Ta= Ta=25 PSRRdB PSRR PSRR k 1k FrequencyHz Figure 19 PSRR vs. Frequency 1k 1M Supply CurrentmA SY SY 1k 1k RbiasΩ 1k 1M Figure 2 Supply Current vs. R BAS 45 Gain ConstantmV/dB Class A and Class AB 2 ±4 ±8 ±12 ±16 ±2 Temperature Figure 21 Gain Constant vs. Temperature Page 6 of 1

7 6. Application Circuit and nformation 6. 1 Basic VCA Configurationm 8V 1kΩ 3 1pF V N1 5Ω 56pF 8V 1kΩ VCA1 N /4 OP482 Vout1 1pF V N2 5Ω 56pF 8V 1kΩ VCA2 N /4 OP482 Vout1 1pF V N3 V N4 5Ω 56pF 8V 1kΩ 5Ω 56pF VCA VCA4 13 Power Supply and Biasing Circuitry 1/4 OP482 Vout1 1pF 1/4 OP482 Vout V GND V MODE Open Class AB (7.5kΩ Class A) V V This is the basic application circuit of V2164M/D.,Each of the four channels is configured identically. A 3 k Ω resistor converts the input voltage to an input current for the VCA. Additionally, a 5 Ω resistor in series with a 56 pf capacitor must be added from each input to ground to ensure stable operation. The output current pin should be maintained at a virtual ground using an external amplifier. Page 7 of 1

8 6. 2 Low Cost, FourChannel Mixer 3 V N1 5Ω 2 4 VCA1 56pF 6 1pF V N2 5Ω 56pF 7 5 VCA2 11 OP176 Vout1 V N Ω VCA3 56pF 14 V N4 13 5Ω 56pF VCA4 Power Supply and Biasing Circuitry V GND V MODE open for Class AB (7.5kΩ for class A) V V The four VCAs in a single package can be configured to create a simple fourchannel mixer. The inputs and control ports are configured the same as for the basic VCA, but the outputs are summed into a single output amplifier. Additional V2164M/D could be added to increase the number of mixer channels by simply summing their outputs into the same output amplifier. Another possible configuration is to use a dual amplifier such as the OP275 to create a stereo, two channel mixer with a single V2164M/D.f additional V2164M/Ds are added, the 1 pf capacitor may need to be increased to ensure stability of the output amplifier. Most op amps are sensitive to capacitance on their inverting inputs. The capacitance forms a pole with the feedback resistor, which reduces the high frequency phase margin. As more V2164M/D s are added to the mixer circuit, their output capacitance and the parasitic trace capacitance add, increasing the overall input capacitance. ncreasing the feedback capacitor will maintain the stability of the output amplifier. Page 8 of 1

9 6.3 Digital Control of the V2164M/D V VrefOUT1V Vod DAC8426 1V Reference 2 6 Latch A DAC A Vout A 7 5 MSB LAB 7 14 Data Bus Latch B Latch C DAC B DAC C 1 Vout B 2 Vout C WR A1 A Logic Control Latch D DAC D Vout D Power Supply and Biasing Circuitry V GND V MODE Vss AGND DGND Open Class AB (7.5kΩ Class A) V V Using a voltage output digitaltoanalog converter such as DAC8426 also can control the gain and attenuation of the V2164M/D. n Digitally Controlled system, its simple 8bit parallel interface can easily be connected to a microcontroller or microprocessor, The coltage output of D/A provedes a low impenence drive to the V2164M/D, so the attenuation can be controlled accurately. The input and output configuration for the V2164M/D is the same as for the basic VCA circuit shown. The 4to1 mixer configuration could also be used. 6.4 V2164M/D Single Supply Operation V=8V 1.8kΩ for class A Rb open for class B 1pF V N 1uF 5Ω 56pF V MODE GND V Rb 1/4 OP482 Vout db gain at =V/2 V V V/2 OP176 1kΩ to additional OP482 1kΩ 1uF The V2164M/D can easily be operated from a single power supply as low as 8V or as high as 36V. The key to using a single supply is to reference all groung connection to a voltage midway between the supplly Page 9 of 1

10 and ground.,as shown above. The OP176 is used to create a pseudeground reference for the V2164M/D.Both the OP482 and OP176 are single supply amplifiers, and can operate over the same voltage range as the V2164M/D, with little or no change in performance. 7. Package Dimensions Page 1 of 1

OBSOLETE. Low Cost Quad Voltage Controlled Amplifier SSM2164 REV. 0

OBSOLETE. Low Cost Quad Voltage Controlled Amplifier SSM2164 REV. 0 a FEATURES Four High Performance VCAs in a Single Package.2% THD No External Trimming 12 db Gain Range.7 db Gain Matching (Unity Gain) Class A or AB Operation APPLICATIONS Remote, Automatic, or Computer