VCA610

VCA610 BURR-BROWN | Alldatasheet

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© 1992 Burr-Brown Corporation PDS-1140D Printed in U.S.A. January, 1995

DESCRIPTION

The VCA610 is a wideband, continuously variable, voltage controlled gain amplifier. It provides linear- dB gain control with high impedance inputs. It is designed to be used as a flexible gain control element in a variety of electronic systems. The VCA610 has a gain control range of 80dB (–40dB to +40dB) providing both gain and attenuation for maximum flexibility in a small 8-lead SO-8 or plastic dual-in-line package. The broad attenuation range can be used for gradual or controlled channel turn-on and turn-off for applications in which abrupt gain changes can create artifacts or other errors. In addition, the output can be disabled to provide –80dB of attenua- tion. Group delay variation with gain is typically less than ±2ns across a bandwidth of 1 to 15MHz. The VCA610 has a noise figure of 3.5dB (with an RS of 200Ω ) including the effects of both current and voltage noise. Instantaneous output dynamic range is 70dB for gains of 0dB to +40dB with 1MHz noise bandwidth. The output is capable of driving 100Ω . The high speed, 300dB/µs, gain control signal is a unipolar (0 to –2V) voltage that varies the gain lin- early in dB/V. VCA610

FEATURES

l WIDE GAIN CONTROL RANGE: 80dB l SMALL PACKAGE: 8-pin SOIC or DIP l WIDE BANDWIDTH: 30MHz l LOW VOLTAGE NOISE: 2.2nV/ √Hz l FAST GAIN SLEW RATE: 300dB/ µs l EASY TO USE WIDEBAND VOLTAGE CONTROLLED AMPLIFIER

APPLICATIONS

l OPTICAL DISTANCE MEASUREMENT l AGC AMPLIFIER l ULTRASOUND l SONAR l ACTIVE FILTERS l LOG AMPLIFIER l IF CIRCUITS l CCD CAMERAS The VCA610 is designed with a very fast overload recovery time of only 200ns. This allows a large signal transient to overload the output at high gain, without obscuring low-level signals following closely behind. The excellent overload recovery time and distortion specifications optimize this device for low- level doppler measurements. +5V –5V VOUT –In +In VC Gain Control VCA610 International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111 Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132 VCA610 VCA610

All specifications at VS = ±5V, RL = 500Ω , RS = 0Ω , and TA = +25°C, unless otherwise noted. VCA610PA, UA VCA610P, U PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS NOTES: (1) See Input/Output Range discussion in Applications Information Section (Figure 2). (2) Gain is laser trimmed and tested at gains of –40dB, 0dB, +15dB, +25dB, and +40dB; VIN =1Vp-p for gains less than 0dB; VOUT = 1V for gains of 0dB to +40dB. (3) Output offset change from offset at G = –40dB. (4) Gain = +40dB; Input step of 2V to 2mV; time required for output to return from saturation to linear operation. (5) VIN = 7mVp-p, VOUT = 700mVp-p (250mVrms); Output Power = –10dBm/tone, equal amplitude tones of 5MHz ±500Hz, G = +40dB. See typical performance curves. (6) With RS = 0Ω , and noise bandwidth of 1MHz. IDR = 20 log (VORMS /(eORMS x √BW)); where VORMS is rms output voltage, eORMS is output noise spectral density, and BW is noise bandwidth. Symmetrical to Ground (±10%) INPUT NOISE Input Voltage Noise G = +40dB, R S = 0Ω 2.2 * nV/ √Hz Input Current Noise G = –40dB to +40dB 1.4 * pA/ √Hz Noise Figure G = +40dB, R S = 200Ω 3.5 * dB INPUT Input Impedance Common-Mode 1 || 1 * M Ω || pF Bias Current All Gains 6 * µA Offset Current All Gains 2 * µA Differential Voltage Range (1) * Common-Mode Voltage Range ±2.5 * V Common-Mode Rejection 50 * dB GAIN Specified Gain Range –40 +40 * * dB Gain Accuracy(2) –40dB ≤ G ≤ +40dB ±0.5 ±2 ±2 ±4d B Gain Accuracy Temperature Drift T A = –25°C to +85°C ±0.01 * dB/ °C Gain with Output Disabled +0.1V ≤ VC ≤ +2.0V, f = 1MHz –80 * dB GAIN CONTROL Gain Scaling Factor –40dB ≤ G ≤ +40dB 40 * dB/V Control Voltage (VC) G = –40dB (V C = 0V) to +40dB (VC = –2V) 0 –2 * * V Bandwidth –3dB 1 * MHz Slew Rate 80dB Gain Step 300 * dB/ µs Settling Time: 1% V IN = 10mVDC, Δ G = 80dB 800 * ns Input Impedance 1 || 1 * M Ω || pF Input Bias Current All Gains 2 * µA Output Offset Change(3) Δ G = 80dB ±30 ±75 * ±125 mV FREQUENCY RESPONSE Bandwidth, Small-Signal –3dB, All Gains 30 * MHz Bandwidth, Large-Signal V O = 1Vp-p, G ≥ 0dB 25 * MHz Group Delay Unit-to-Unit Variation 0dB ≤ G ≤ +40dB f = 1 to 15MHz ±1* n s –40dB ≤ G < 0dB f = 1 to 15MHz ±2* n s Output Slew Rate V O = 1Vp-p 60 * V/ µs Overload Recovery(4) 200 * ns Two-tone Intermodulation Distortion(5) Small-Signal –50 * dBc Two-tone, 3rd Order IMD Intercept(5) Small-Signal 15 * dBm OUTPUT Voltage Swing(1) Output Voltage Limit * Short-Circuit Current Continuous to Common ±80 * mA Instantaneous Dynamic Range (IDR)(6) G = 0dB to +40dB V O = 1.5Vp-p 70 * dB Offset G = –40dB ±2 ±30 * * mV Output Resistance f = 1MHz, All Gains 10 * Ω POWER SUPPLY Specification ±5V Recommended ±4.5 ±5.5 * * V PSR G = 0dB 40 50 * dB Quiescent Current –26/+30 ±32 * * mA TEMPERATURE Specification Applies to Temperature Drift Specs –25 +85 * * °C Operation –40 +125 * * °C Thermal Resistance, θJA P, PA 100 * °C/W U, UA 125 * °C/W

–VS +V S –In VOUT VCA610 GND +In Gain Control, VC No Internal Connection The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant any BURR-BROWN product for use in life support devices and/or systems. ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDERING INFORMATION PACKAGE DRAWING PRODUCT PACKAGE NUMBER (1) VCA610PA 8-Pin Plastic DIP 006 VCA610P 8-Pin Plastic DIP 006 VCA610UA SO-8 Surface-Mount 182 VCA610U SO-8 Surface-Mount 182 NOTE:(1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. ELECTROSTATIC DISCHARGE SENSITIVITY This integrated circuit can be damaged by ESD. Burr-Brown recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degrada- tion to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.

NOISE FIGURE vs SOURCE RESISTANCE Source Resistance (Ω ) NF (dB) 10 100 1k 10k 100k NF dB = 10 log 1 +en 2 + (inR S)2 4kTR S VOLTAGE AND CURRENT NOISE vs GAIN Gain (dB) 10k 100 –40 –20 0 +20 +40 Voltage Noise (nV/√Hz) 100 0.1 Current Noise (pA/√Hz)Output Voltage Noise Input Current Noise Input-Referred Voltage Noise GAIN CONTROL RESPONSE Frequency (Hz) Normalized Response (dB) –12 –15 10k 100k 1M 10M 100M GAIN vs CONTROL VOLTAGE Control Voltage, VC (V) Gain (dB) –20 –40 –60 –80 Output Disabled for +0.1V ≤ VC ≤ +2V Specified Operating Range SMALL-SIGNAL RESPONSE vs GAIN Frequency (MHz) 0.1 1.0 10 100 Gain (dB) –10 –20 –30 –40 –50 VC = –2.0V VC = –1.5V VC = –1.0V VC = –0.5V VC = 0V Large Signal, VO = 1Vp-p TYPICAL PERFORMANCE CURVES At VS = ±5V, RL = 500Ω , RS = 0Ω , and TA = +25°C, unless otherwise noted. FEEDTHRU WITH OUTPUT DISABLED Frequency (MHz) Disabled Gain (dB) –20 –40 –60 –80 –100 0.1 1 10 100 Output Disabled for +0.1V ≤ VC ≤ +2V

Frequency (Hz) Rejection (dB) 10k 100k 1M 10M 100M –PSR +PSR CMR G = 0dB OUTPUT OFFSET CHANGE vs GAIN Gain (dB) Output Offset Change (mV) 150 100 –50 –100 –150 –40 –20 0 20 40 Change from Output Offset at G = –40dB Specification Limit Low Grade High Grade 2-TONE, 3rd ORDER INTERMODULATION INTERCEPT vs GAIN Gain (dB) Intercept Point (dBm) –10 –20 –30 –40 –40 –20 0 20 40 10MHz1MHz GROUP DELAY vs GAIN Gain (dB) Group Delay (ns) –40 –20 0 20 40 1MHz 10MHz 15MHz 02 5 5 0 “DIAMOND PATTERN” RESPONSE Time (µs) 0 100 200 LARGE SIGNAL RESPONSE Time (µs) TYPICAL PERFORMANCE CURVES (CONT) Output Voltage (mV) Output Voltage (mV) G = +40dB f = 5MHz R L = 500Ω +500 –500 At VS = ±5V, RL = 500Ω , RS = 0Ω , and TA = +25°C, unless otherwise noted. –500 +500

I below summarizes these results. tion of the offset effects produces the greatest output offset. would otherwise couple to the amplifier input. required, a ground-referenced bipolar voltage is needed. to prevent saturation of internal circuitry. FIGURE 3. Optional Offset Adjustment and Control Line 3a) Optional Offset Adjustment. bypassed to ground as close as possible to the amplifier pins. vide excellent results due to their low lead inductance. recover from most overload conditions in 200ns or less. TABLE I. Output Signal Compression.

FIGURE 6. Two Series Connected VCA610s Expand the Gain Range and Improve Noise Performance. V CA1 serves as a low-noise, fixed-gain preamp. segment of the composite gain range. FIGURE 8. Adding Wein-bridge Feedback to the AGC Circuit of Figure 7 Produces an Amplitude Stabilized Oscillator.

0.1 VDC

R 1 through R3 that determine attack and release times. ward biasing the diode and charging the holding capacitor. the attack time of this AGC correction. overload of the VCA610’s gain control circuit. FIGURE 7. This AGC Circuit Maintains a Constant Output Amplitude for a 1000:1 Input Range.