a Single Supply, Low Power Triple Video Amplifier AD813 FEATURES Low Cost Three Video Amplifiers in One Package Optimized for Driving Cables in Video Systems Excellent Video Specifications (RL = 150 V) Gain Flatness 0.1 dB to 50 MHz 0.03% Differential Gain Error 0.068 Differential Phase Error Low Power Operates on Single +3 V to 615 V Power Supplies 5.5 mA/Amplifier Max Power Supply Current High Speed 125 MHz Unity Gain Bandwidth (–3 dB) 500 V/ms Slew Rate High Speed Disable Function per Channel Turn-Off Time 80 ns Easy to Use 50 mA Output Current Output Swing to 1 V of Rails APPLICATIONS Video Line Driver LCD Drivers Computer Video Plug-In Boards Ultrasound RGB Amplifier CCD Based Systems PRODUCT DESCRIPTION The AD813 is a low power, single supply triple video amplifier. Each of the three current feedback amplifiers has 50 mA of output current, and is optimized for driving one back-terminated video load (150 Ω). The AD813 features gain flatness of 0.1 dB to PIN CONFIGURATION 14-Lead DIP and SOIC DISABLE1 1 14 OUT2 DISABLE2 2 13 –IN2 DISABLE3 3 12 +IN2 VS+ 4 +IN1 5 AD813 11 VS– 10 +IN3 –IN1 6 9 –IN3 OUT1 7 8 OUT3 50 MHz while offering differential gain and phase error of 0.03% and 0.06°. This makes the AD813 ideal for broadcast and consumer video electronics. The AD813 offers low power of 5.5 mA per amplifier max and runs on a single +3 V power supply. The outputs of each amplifier swing to within one volt of either supply rail to easily accommodate video signals. While operating on a single +5 V supply the AD813 still achieves 0.1 dB flatness to 20 MHz and 0.05% & 0.05° of differential gain and phase performance. All this is offered in a small 14-lead plastic DIP or SOIC package. These features make this triple amplifier ideal for portable and battery powered applications where size and power are critical. The outstanding bandwidth of 125 MHz along with 500 V/µs of slew rate make the AD813 useful in many general purpose, high speed applications where a single +3 V or dual power supplies up to ± 15 V are needed. Furthermore the AD813 contains a high speed disable function for each amplifier in order to power down the amplifier or high impedance the output. This can then be used in video multiplexing applications. The AD813 is available in the industrial temperature range of –40°C to +85°C in plastic DIP and SOIC packages as well as chips. G = +2 RL = 150V NORMALIZED GAIN – dB 0.2 500mV 615V 500ns 0.1 100 0 90 –0.1 65V –0.2 3V –0.3 5V –0.4 10 –0.5 100k 0% 1M 10M 100M 5V FREQUENCY – Hz Figure 1. Fine Scale Gain Flatness vs. Frequency, G = +2, RL = 150 Ω Figure 2. Channel Switching Characteristics for a 3:1 Mux REV. B 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: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 1998 AD813* PRODUCT PAGE QUICK LINKS Last Content Update: 02/23/2017 COMPARABLE PARTS DESIGN RESOURCES View a parametric search of comparable parts. • AD813 Material Declaration • PCN-PDN Information EVALUATION KITS • Quality And Reliability • AD813 Evaluation Board • Symbols and Footprints DOCUMENTATION DISCUSSIONS Data Sheet View all AD813 EngineerZone Discussions. • AD813: Military Data Sheet • AD813: Single Supply, Low Power Triple Video Amplifier Data Sheet SAMPLE AND BUY Visit the product page to see pricing options. User Guides • UG-114: Universal Evaluation Board for Triple, High Speed Op Amps Offered in 14-Lead SOIC Packages TOOLS AND SIMULATIONS • AD813 SPICE Macro-Model REFERENCE MATERIALS TECHNICAL SUPPORT Submit a technical question or find your regional support number. DOCUMENT FEEDBACK Submit feedback for this data sheet. Tutorials • MT-034: Current Feedback (CFB) Op Amps • MT-051: Current Feedback Op Amp Noise Considerations • MT-057: High Speed Current Feedback Op Amps • MT-059: Compensating for the Effects of Input Capacitance on VFB and CFB Op Amps Used in Current-toVoltage Converters This page is dynamically generated by Analog Devices, Inc., and inserted into this data sheet. A dynamic change to the content on this page will not trigger a change to either the revision number or the content of the product data sheet. This dynamic page may be frequently modified. AD813–SPECIFICATIONS Dual Supply (@ T = +258C, R = 150 V, unless otherwise noted) A L Model DYNAMIC PERFORMANCE –3 dB Bandwidth Bandwidth for 0.1 dB Flatness Slew Rate1 Conditions VS Min AD813A Typ Max Units G = +2, No Peaking ±5 V ± 15 V 45 75 65 100 MHz MHz G = +2 ±5 V ± 15 V ±5 V ± 15 V ±5 V ± 15 V 15 25 25 50 150 250 225 450 MHz MHz V/µs V/µs V/µs V/µs ±5 V ± 15 V 50 40 ns ns ± 15 V ± 5 V, ± 15 V ± 5 V, ± 15 V ± 5 V, ± 15 V ±5 V ± 15 V ±5 V ± 15 V –90 3.5 1.5 18 0.08 0.03 0.13 0.06 dBc nV√Hz pA√Hz pA√Hz % % Degrees Degrees ± 5 V, ± 15 V 2 ± 5 V, ± 15 V ± 5 V, ± 15 V 15 5 ± 5 V, ± 15 V 0.5 G = +2, RL = 1 kΩ G = –1, RL = 1 kΩ Settling Time to 0.1% NOISE/HARMONIC PERFORMANCE Total Harmonic Distortion Input Voltage Noise Input Current Noise Differential Gain Error G = –1, RL = 1 kΩ VO = 3 V Step VO = 10 V Step fC = 1 MHz, RL = 1 kΩ f = 10 kHz f = 10 kHz, +In –In NTSC, G = ± 2, RL = 150 Ω Differential Phase Error DC PERFORMANCE Input Offset Voltage TMIN–TMAX Offset Drift –Input Bias Current TMIN–TMAX +Input Bias Current Open-Loop Voltage Gain Open-Loop Transresistance INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common Mode Voltage Range Common-Mode Rejection Ratio Input Offset Voltage –Input Current ± Input Current Input Offset Voltage –Input Current +Input Current TMIN–TMAX VO = ± 2.5 V, RL = 150 Ω TMIN–TMAX VO = ± 10 V, RL = 1 kΩ TMIN–TMAX VO = ± 2.5 V, RL = 150 Ω TMIN–TMAX VO = ± 10 V, RL = 1 kΩ TMIN–TMAX ±5 V ± 15 V ±5 V ± 15 V +Input –Input +Input ± 15 V ± 15 V ± 15 V ±5 V ± 15 V VCM = ± 2.5 V ±5 V VCM = ± 10 V ± 15 V –2– 150 69 66 73 72 300 200 400 300 0.09 0.12 5 12 30 35 1.7 2.5 76 82 500 900 15 65 1.7 ± 4.0 ± 13.5 54 57 58 2 0.07 62 1.5 0.05 mV mV µV/°C µA µA µA µA dB dB dB dB kΩ kΩ kΩ kΩ MΩ Ω pF V V 3 0.15 3.0 0.1 dB µA/V µA/V dB µA/V µA/V REV. B AD813 Model OUTPUT CHARACTERISTICS Output Voltage Swing Conditions VS Min RL = 150 Ω, TMIN–TMAX RL = 1 kΩ, TMIN–TMAX ±5 V ± 15 V ±5 V ± 15 V ± 15 V 3.5 13.6 25 30 Output Current Short Circuit Current G = +2, RF = 715 Ω VIN = 2 V AD813A Typ ±V ±V mA mA mA dB dB G = +2, f = 5 MHz G = +2, f = 40 MHz ± 5 V, ± 15 V ± 15 V –65 0.1 TMIN–TMAX TMIN–TMAX ± 5 V, ± 15 V ± 5 V, ± 15 V 0.5 2 POWER SUPPLY Operating Range Quiescent Current Per Amplifier ±5 V ± 15 V ± 15 V ±5 V ± 15 V Power Supply Rejection Ratio Input Offset Voltage –Input Current +Input Current DISABLE CHARACTERISTICS Off Isolation Off Output Impedance Channel-to-Channel Isolation Turn-On Time Turn-Off Time TMIN–TMAX Per Amplifier VS = ± 1.5 V to ± 15 V f = 5 MHz G = +1 2 or 3 Channels Mux, f = 5 MHz NOTES 1 Slew rate measurement is based on 10% to 90% rise time in the specified closed-loop gain. Specifications subject to change without notice. REV. B –3– 3.5 25 mV µA 0.5 0.75 ± 18 4.0 5.5 6.7 0.65 1.0 V mA mA mA mA mA 80 0.3 0.005 0.8 0.05 dB µA/V µA/V ± 1.2 3.5 4.5 72 Units 3.8 14.0 40 50 100 MATCHING CHARACTERISTICS Dynamic Crosstalk Gain Flatness Match DC Input Offset Voltage –Input Bias Current Quiescent Current, Powered Down Max ± 5 V, ± 15 V ± 5 V, ± 15 V ± 5 V, ± 15 V –57 12.5 –65 dB pF dB ± 5 V, ± 15 V 100 80 ns ns AD813–SPECIFICATIONS Single Supply (@ T = +258C, R = 150 V, unless otherwise noted) A L Model DYNAMIC PERFORMANCE –3 dB Bandwidth Bandwidth for 0.1 dB Flatness Slew Rate1 NOISE/HARMONIC PERFORMANCE Input Voltage Noise Input Current Noise Differential Gain Error2 Differential Phase Error2 AD813A Typ Max Conditions VS Min G = +2, No Peaking +5 V +3 V 35 25 50 40 MHz MHz G = +2 +5 V +3 V +5 V +3 V 12 8 20 15 100 50 MHz MHz V/µs V/µs +5 V, +3 V +5 V, +3 V +5 V, +3 V +5 V +3 V +5 V +3 V 3.5 1.5 18 0.05 0.2 0.05 0.2 nV√Hz pA√Hz pA√Hz % % Degrees Degrees +5 V, +3 V 1.5 +5 V, +3 V +5 V, +3 V 7 7 +5 V, +3 V 0.5 G = +2, RL = 1 kΩ f = 10 kHz f = 10 kHz, +In –In NTSC, G = +2, RL = 150 Ω G = +1 G = +2 G = +1 DC PERFORMANCE Input Offset Voltage TMIN–TMAX Offset Drift –Input Bias Current TMIN–TMAX +Input Bias Current Open-Loop Voltage Gain Open-Loop Transresistance INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common Mode Voltage Range Common-Mode Rejection Ratio Input Offset Voltage –Input Current +Input Current Input Offset Voltage –Input Current +Input Current OUTPUT CHARACTERISTICS Output Voltage Swing p-p TMIN–TMAX VO = +2.5 V p-p VO = +0.7 V p-p VO = +3 V p-p VO = +1 V p-p +5 V +3 V +5 V +3 V +Input –Input +Input 180 +5 V, +3 V +5 V VCM = 1.25 V to 3.75 V 1.0 1.0 +5 V 54 +3 V RL = 150 Ω, TMIN–TMAX +5 V +3 V +5 V +3 V +5 V G = +2, RF = 715 Ω VIN = 1 V –4– 30 40 1.7 2.5 70 69 300 225 15 90 2 +5 V +3 V VCM = 1 V to 2 V Output Current Short Circuit Current 65 5 10 3.0 1.0 20 15 4.0 2.0 58 3 0.1 56 3.5 0.1 3.2 1.3 30 25 40 6.5 0.2 Units mV mV µV/°C µA µA µA µA dB dB kΩ kΩ MΩ Ω pF V V dB µA/V µA/V dB µA/V µA/V ± V p-p ± V p-p mA mA mA REV. B AD813 Model Conditions VS Min AD813A Typ MATCHING CHARACTERISTICS Dynamic Crosstalk Gain Flatness Match DC Input Offset Voltage –Input Bias Current G = +2, f = 5 MHz G = +2, f = 20 MHz +5 V, +3 V +5 V, +3 V –65 0.1 TMIN–TMAX TMIN–TMAX +5 V, +3 V +5 V, +3 V 0.5 2 POWER SUPPLY Operating Range Quiescent Current Per Amplifier +5 V +3 V +5 V +5 V +3 V Quiescent Current, Powered Down Power Supply Rejection Ratio Input Offset Voltage –Input Current +Input Current DISABLE CHARACTERISTICS Off Isolation Off Output Impedance Channel-to-Channel Isolation Turn-On Time Turn-Off Time 2.4 TMIN–TMAX Per Amplifier 3.2 3.0 0.4 0.4 VS = +3.0 V to +30 V f = 5 MHz G = +1 2 or 3 Channel Mux, f = 5 MHz Max Units dB dB 3.5 25 mV µA 36 4.0 4.0 5.0 0.6 0.5 V mA mA mA mA mA 76 0.3 0.005 dB µA/V µA/V +5 V, +3 V +5 V, +3 V +5 V, +3 V –55 13 –65 dB pF dB +5 V, +3 V 100 80 ns ns TRANSISTOR COUNT 111 NOTES 1 Slew rate measurement is based on 10% to 90% rise time in the specified closed-loop gain. 2 Single supply differential gain and phase are measured with the ac coupled circuit of Figure 52. Specifications subject to change without notice. ABSOLUTE MAXIMUM RATINGS 1 Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V Internal Power Dissipation2 Plastic (N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 Watts Small Outline (R) . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 Watts Input Voltage (Common Mode) . . . . . . . . . . . . . . . . . . . ± VS Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . ± 6 V Output Short Circuit Duration . . . . . . . . . . . . . . . . . . . . . . . Observe Power Derating Curves Storage Temperature Range N, R . . . . . . . . –65°C to +125°C Operating Temperature Range AD813A . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C Lead Temperature Range (Soldering 10 sec) . . . . . . . +300°C ORDERING GUIDE Model AD813AN AD813AR-14 AD813ACHIPS AD813AR-REEL AD813AR-REEL7 5962-9559601M2A* Package Description Package Options –40°C to +85°C –40°C to +85°C –40°C to +85°C 14-Lead Plastic DIP N-14 14-Lead Plastic SOIC R-14 Die Form 13" REEL 7" REEL –55°C to +125°C 20-Lead LCC *Refer to official DSCC drawing for tested specifications and pin configuration. 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 Specification is for device in free air: 14-Lead Plastic DIP Package: θJA = 75°C/W 14-Lead SOIC Package: θJA = 120°C/W REV. B Temperature Range –5– AD813 2.5 Maximum Power Dissipation TJ = +150 C MAXIMUM POWER DISSIPATION – Watts The maximum power that can be safely dissipated by the AD813 is limited by the associated rise in junction temperature. The maximum safe junction temperature for the plastic encapsulated parts is determined by the glass transition temperature of the plastic, about 150°C. Exceeding this limit temporarily may cause a shift in parametric performance due to a change in the stresses exerted on the die by the package. Exceeding a junction temperature of 175°C for an extended period can result in device failure. While the AD813 is internally short circuit protected, this may not be enough to guarantee that the maximum junction temperature (150°C) is not exceeded under all conditions. To ensure proper operation, it is important to observe the derating curves. 2.0 14-LEAD DIP PACKAGE 1.5 14-LEAD SOIC 1.0 0.5 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 AMBIENT TEMPERATURE – C 70 80 90 Figure 3. Maximum Power Dissipation vs. Ambient Temperature It must also be noted that in (noninverting) gain configurations (with low values of gain resistor), a high level of input overdrive can result in a large input error current, which may result in a significant power dissipation in the input stage. This power must be included when computing the junction temperature rise due to total internal power. METALIZATION PHOTO Dimensions shown in inches and (mm). +IN2 12 0.124 (3.15) VS– 11 VS– 11 VS– 11 +IN3 10 9 –IN3 –IN2 13 8 OUT3 OUT2 14 0.057 (1.45) 7 OUT1 DISABLE1 1 DISABLE2 2 3 DISABLE3 4 VS+ 5 +IN1 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 AD813 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. –6– 6 –IN1 WARNING! ESD SENSITIVE DEVICE REV. B AD813 20 18 15 VS = 615V SUPPLY CURRENT – mA COMMON-MODE VOLTAGE RANGE – 6Volts 20 10 5 16 14 VS = 65V 12 10 0 0 5 10 15 SUPPLY VOLTAGE – 6Volts 8 –60 20 –40 –20 0 20 40 60 80 100 120 140 JUNCTION TEMPERATURE – C Figure 4. Input Common-Mode Voltage Range vs. Supply Voltage Figure 7. Supply Current vs. Junction Temperature 20 13 TA = +25 C SUPPLY CURRENT – mA OUTPUT VOLTAGE – V p-p 12 15 NO LOAD 10 RL = 150V 5 11 10 9 0 0 5 10 15 SUPPLY VOLTAGE – 6Volts 8 20 2 4 6 10 8 12 14 16 SUPPLY VOLTAGE – ±Volts Figure 8 Supply Current vs. Supply Voltage at Low Voltages Figure 5. Output Voltage Swing vs. Supply Voltage 25 30 615V SUPPLY 20 25 15 INPUT BIAS CURRENT – mA OUTPUT VOLTAGE – V p-p 0 20 15 10 65V SUPPLY 5 10 –IB, VS = 65V 5 0 +IB, VS = 65V, 615V –5 –IB, VS = 615V –10 –15 –20 0 10 100 1k –25 –60 10k LOAD RESISTANCE – V –20 0 20 40 60 80 100 120 140 JUNCTION TEMPERATURE – C Figure 6. Output Voltage Swing vs. Load Resistance REV. B –40 Figure 9. Input Bias Current vs. Junction Temperature –7– AD813 4 70 VS = 65V 0 60 OUTPUT CURRENT – mA INPUT OFFSET VOLTAGE – mV 2 –2 –4 VS = 615V –6 –8 –10 –12 50 40 30 –14 –16 –60 –40 –20 0 20 40 60 80 100 120 20 140 0 5 JUNCTION TEMPERATURE – C Figure 10. Input Offset Voltage vs. Junction Temperature 20 1k CLOSED-LOOP OUTPUT RESISTANCE – V VS = 615V SHORT CIRCUIT CURRENT – mA 15 Figure 13. Linear Output Current vs. Supply Voltage 160 140 SINK 120 100 SOURCE 80 60 40 –60 10 SUPPLY VOLTAGE – 6Volts –40 –20 0 20 40 60 80 100 120 G = +2 100 10 1 5VS 0.1 15VS 0.01 10k 140 100k 1M FREQUENCY – Hz JUNCTION TEMPERATURE – C Figure 11. Short Circuit Current vs. Junction Temperature 10M 100M Figure 14. Closed-Loop Output Resistance vs. Frequency 1M 80 ΩOUTPUT RESISTANCE – V OUTPUT CURRENT – mA 70 60 50 VS = 65V 40 VS = 615V 100k 10k 1k 30 20 –60 –40 –20 0 20 40 60 80 100 120 100 100k 140 JUNCTION TEMPERATURE – C 1M 10M 100M FREQUENCY – Hz Figure 12. Linear Output Current vs. Junction Temperature Figure 15. Output Resistance vs. Frequency, Disabled State –8– REV. B AD813 120 VS = 615V PHASE –45 10 10 VOLTAGE NOISE TRANSIMPEDANCE – dB INVERTING INPUT CURRENT NOISE CURRENT NOISE – pA/ Hz VOLTAGE NOISE – nV/ Hz –90 GAIN 100 1k FREQUENCY – Hz VS = 3V 40 10k VS = 615V 100k 1M FREQUENCY – Hz 10M 100M Figure 19. Open-Loop Transimpedance vs. Frequency (Relative to 1 Ω) Figure 16. Input Current and Voltage Noise vs. Frequency 90 –30 681V 80 G = +2 VO = 2V p-p VS = 615V: RL = 1kV VS = 65V: RL = 150V 681V VIN VOUT HARMONIC DISTORTION – dBc COMMON-MODE REJECTION – dB –180 60 1 100k 10k VS = 3V 80 NONINVERTING INPUT CURRENT NOISE 1 10 –135 100 PHASE – Degrees 0 100 100 70 681V 681V 60 50 VS = 3V 40 VS = 615V 30 –50 –70 2ND HARMONIC VS = 65V –90 3RD HARMONIC VS = 65V VS = 615V –110 20 2ND 3RD 10 10k 100k 1M FREQUENCY – Hz 10M –130 100M 615V OUTPUT SWING FROM 6V TO 0 POWER SUPPLY REJECTION – dB 10M 100M GAIN = –1 VS = 615V 8 70 60 50 61.5V 30 20 10 6 4 2 1% 0 0.1% 0.025% –2 –4 –6 –8 –10 100k 1M FREQUENCY – Hz 10M 20 100M 40 60 SETTLING TIME – ns 80 Figure 21. Output Swing and Error vs. Settling Time Figure 18. Power Supply Rejection vs. Frequency REV. B 100k 1M FREQUENCY – Hz 10 80 0 10k 10k Figure 20. Harmonic Distortion vs. Frequency Figure 17. Common-Mode Rejection vs. Frequency 40 1k –9– AD813 700 1000 VS = 615V RL = 500V 900 600 G = +10 500 700 SLEW RATE – V/ms SLEW RATE – V/ms 800 600 G = +10 500 400 G = –1 300 400 G = –1 300 G = +2 200 G = +2 200 100 100 G = +1 G = +1 0 0 0 1 2 3 4 5 6 7 8 9 10 0 1.5 3.0 4.5 Figure 22. Slew Rate vs. Output Step Size AAA A AA A A AAA AA A AAAA AAAA A AAA A AA A A A A A AAAA AA AAAAA 2V 500m V 100 VIN 90 VIN 10 VOUT 65V –90 –180 +1 CLOSED-LOOP GAIN – dB 0 GAIN –270 VS = 615V 65V 5V 20n s 90 0% RL = 150V 3V –3 15.0 140 –3dB BANDWIDTH – MHz VS = 615V –2 13.5 Figure 26. Small Signal Pulse Response, Gain = +1, (RF = 750 Ω, RL = 150 Ω, VS = ± 5 V) PHASE SHIFT – Degrees +90 –1 12.0 500m V Figure 23. Large Signal Pulse Response, Gain = +1, (RF = 750 Ω, RL = 150 Ω, VS = ± 5 V) 0 10.5 1 00 2V 5V 9.0 10 VOUT 0% 3V 7.5 Figure 25. Maximum Slew Rate vs. Supply Voltage 50ns PHASE 6.0 SUPPLY VOLTAGE – 6Volts OUTPUT STEP SIZE – V p-p 120 100 RF = 750V 80 RF = 866V 60 RF = 1kV 40 –4 –5 –6 1 10 100 2 1000 FREQUENCY – MHz Figure 24. Closed-Loop Gain and Phase vs. Frequency, G = +1 4 6 8 10 12 SUPPLY VOLTAGE – 6Volts 14 16 Figure 27. –3 dB Bandwidth vs. Supply Voltage, G = +1 –10– REV. B AD813 100 100 90 VIN 90 VIN 10 VOUT 10 VOUT 0% 0% 500mV 500mV G = +10 RL = 150V 65V –90 5V +1 –180 3V GAIN 0 0 –270 VS = 615V –1 5V –2 –3 65V 3V –4 –5 –6 1 10 100 VS = 615V PHASE CLOSED-LOOP GAIN (NORMALIZED) – dB VS = 615V PHASE SHIFT – Degrees PHASE +1 –180 5V GAIN 0 –270 –1 VS = 615V 5V –2 –3 65V 3V –5 –6 1 10 100 FREQUENCY – MHz G = +10 RL = 1kV 90 –3dB BANDWIDTH – MHz –3dB BANDWIDTH – MHz 80 RF = 357V 60 RF = 154V 50 1000 Figure 32. Closed-Loop Gain and Phase vs. Frequency, G = +10, RL = 1 kΩ G = +10 RL = 150V 1dB –360 –4 1000 Figure 29. Closed-Loop Gain and Phase vs. Frequency, G = +10, RL = 150 Ω PEAKING 0 –90 65V 3V FREQUENCY – MHz 70 G = +10 RL = 1kV RF = 649V 40 30 20 RF = 357V 80 70 60 50 RF = 649V RF = 154V 40 30 20 2 4 6 8 10 12 14 16 2 SUPPLY VOLTAGE – 6Volts 4 6 8 10 12 14 16 SUPPLY VOLTAGE – 6Volts Figure 30. –3 dB Bandwidth vs. Supply Voltage, G = +10, RL = 150 Ω REV. B PHASE SHIFT – Degrees Figure 31. Small Signal Pulse Response, Gain = +10, (RF = 357 Ω, RL = 150 Ω, VS = ± 5 V) Figure 28. Large Signal Pulse Response, Gain = +10, (RF = 357 Ω, RL = 500 Ω, VS = ± 15 V) CLOSED-LOOP GAIN (NORMALIZED) – dB 20ns 50mV 50ns 500mV Figure 33. –3 dB Bandwidth vs. Supply Voltage, G = +10, RL = 1 kΩ –11– AD813 2V 500m V 50ns 100 10 0 90 90 10 10 0% 0% 2V 500m V 65V –90 3V 5V CLOSED-LOOP GAIN – dB +1 0 –180 GAIN –270 VS = 615V –1 PHASE 3V –2 65V –3 5V –4 –5 –6 1 10 100 FREQUENCY – MHz VS = 615V 65V –90 +1 –180 5V GAIN 0 –270 –1 VS = 615V –2 3V –3 65V –4 5V –5 –6 10 100 FREQUENCY – MHz 1000 Figure 38. Closed-Loop Gain and Phase vs. Frequency, G = –10, RL = 1 kΩ Figure 35. Closed-Loop Gain and Phase vs. Frequency, G = –1, RL = 150 Ω G = –1 RL = 150V G = –10 RL = 1kV 110 80 100 –3dB BANDWIDTH – MHz –3dB BANDWIDTH – MHz 0 3V 1 1000 G = –10 RL = 1kV PHASE SHIFT – Degrees G = –1 RL = 150V CLOSED-LOOP GAIN (NORMALIZED) – dB VS = 615V PHASE Figure 37. Small Signal Pulse Response, Gain = –1, (RF = 750 Ω, RL = 150 Ω, VS = ± 5 V) PHASE SHIFT – Degrees Figure 34. Large Signal Pulse Response, Gain = –1, (RF = 750 Ω, RL = 150 Ω, VS = ± 5 V) 0 2 0n s PEAKING 1.0dB RF = 681V 90 80 PEAKING 0.2dB RF = 715V 70 60 50 70 RF = 357V 60 RF = 154V 50 RF = 649V 40 30 20 40 2 4 6 8 10 12 14 16 2 SUPPLY VOLTAGE – 6Volts 4 6 8 10 12 14 16 SUPPLY VOLTAGE – 6Volts Figure 36. –3 dB Bandwidth vs. Supply Voltage, G = –1, RL = 150 Ω Figure 39. –3 dB Bandwidth vs. Supply Voltage, G = –10, RL = 1 kΩ –12– REV. B AD813 General Consideration The AD813 is a wide bandwidth, triple video amplifier that offers a high level of performance on less than 5.5 mA per amplifier of quiescent supply current. With its fast acting power down switch, it is designed to offer outstanding functionality and performance at closed-loop inverting or noninverting gains of one or greater. To estimate the –3 dB bandwidth for closed-loop gains or feedback resistors not listed in the above table, the following two pole model for the AD813 may be used: ACL = Built on a low cost, complementary bipolar process, and achieving bandwidth in excess of 100 MHz, differential gain and phase errors of better than 0.1% and 0.1° (into 150 Ω), and output current greater than 40 mA, the AD813 is an exceptionally efficient video amplifier. Using a conventional current feedback architecture, its high performance is achieved through careful attention to design details. where: RF RG f2 s Choice of Feedback & Gain Resistors Because it is a current feedback amplifier, the closed-loop bandwidth of the AD813 depends on the value of the feedback resistor. The bandwidth also depends on the supply voltage. In addition, attenuation of the open-loop response when driving load resistors less than about 250 Ω will also affect the bandwidth. Table I contains data showing typical bandwidths at different supply voltages for some useful closed-loop gains when driving a load of 150 Ω. (Bandwidths will be about 20% greater for load resistances above a few hundred ohms.) ACL = G = rIN = CT = = = = = G (RF + Gr IN)CT S + S (R F + GrIN ) CT + 1 2 π f2 2 closed-loop gain from “transcapacitance” 1 + RF/RG input resistance of the inverting input “transcapacitance,” which forms the open-loop dominant pole with the transresistance feedback resistor gain resistor frequency of second (nondominant) pole 2 πj f Appropriate values for the model parameters at different supply voltages are listed in Table II. Reasonable approximations for these values at supply voltages not found in the table can be obtained by a simple linear interpolation between those tabulated values which ‘bracket’ the desired condition. Table II. Two Pole Model Parameters at Various Supplies Table I. –3 dB Bandwidth vs. Closed-Loop Gain and Feedback Resistor , (RL = 150 V) VS (V) Gain RF (V) BW (MHz) ± 15 +1 +2 +10 –1 –10 866 681 357 681 357 125 100 60 100 55 +1 +2 +10 –1 –10 750 649 154 649 154 75 65 40 70 40 +1 +2 +10 –1 –10 715 619 154 619 154 60 50 30 50 30 +1 +2 +10 –1 –10 681 619 154 619 154 50 40 25 40 20 ±5 +5 +3 VS (V) rIN (V) CT (pF) f2 (MHz) ± 15 ±5 +5 +3 85 90 105 115 2.5 3.8 4.8 5.5 150 125 105 95 As discussed in many amplifier and electronics textbooks (such as Roberge’s Operational Amplifiers: Theory and Practice), the –3 dB bandwidth for the 2-pole model can be obtained as: [ f 3 = f n 1 − 2d 2 + (2 − 4d 2 + 4d 4 )1/2 1/2 1/2 f2 ( R + Gr ) C IN T F where: fn = and: d= [ 1 f 2 (R F +Gr IN ) C T 2 ]1/2 This model will predict –3 dB bandwidth within about 10% to 15% of the correct value when the load is 150 Ω. However, it is not accurate enough to predict either the phase behavior or the frequency response peaking of the AD813. The choice of feedback resistor is not critical unless it is important to maintain the widest, flattest frequency response. The resistors recommended in the table are those (metal film values) that will result in the widest 0.1 dB bandwidth. In those applications where the best control of the bandwidth is desired, 1% metal film resistors are adequate. Wider bandwidths can be attained by reducing the magnitude of the feedback resistor (at the expense of increased peaking), while peaking can be reduced by increasing the magnitude of the feedback resistor. REV. B ] –13– AD813 Printed Circuit Board Layout Guidelines As with all wideband amplifiers, printed circuit board parasitics can affect the overall closed-loop performance. Most important for controlling the 0.1 dB bandwidth are stray capacitances at the output and inverting input nodes. Increasing the space between signal lines and ground plane will minimize the coupling. Also, signal lines connecting the feedback and gain resistors should be kept short enough that their associated inductance does not cause high frequency gain errors. Power Supply Bypassing Adequate power supply bypassing can be very important when optimizing the performance of high speed circuits. Inductance in the supply leads can (for example) contribute to resonant circuits that produce peaking in the amplifier’s response. In addition, if large current transients must be delivered to a load, then large (greater than 1 µF) bypass capacitors are required to produce the best settling time and lowest distortion. Although 0.1 µF capacitors may be adequate in some applications, more elaborate bypassing is required in other cases. A carefully laid-out PC board should be able to achieve the level of crosstalk shown in the figure. The most significant contributors to difficulty in achieving low crosstalk are inadequate power supply bypassing, overlapped input and/or output signal paths, and capacitive coupling between critical nodes. The bypass capacitors must be connected to the ground plane at a point close to and between the ground reference points for the loads. (The bypass of the negative power supply is particularly important in this regard.) This requires careful planning as there are three amplifiers in the package, and low impedance signal return paths must be provided for each load. (Using a parallel combination of 1 µF, 0.1 µF, and 0.01 µF bypass capacitors will help to achieve optimal crosstalk.) The input and output signal return paths (to the bypass caps) must also be kept from overlapping. Since ground connections are not of perfectly zero impedance, current in one ground return path can produce a voltage drop in another ground return path if they are allowed to overlap. When multiple bypass capacitors are connected in parallel, it is important to be sure that the capacitors themselves do not form resonant circuits. A small (say 5 Ω) resistor may be required in series with one of the capacitors to minimize this possibility. Electric field coupling external to (and across) the package can be reduced by arranging for a narrow strip of ground plane to be run between the pins (parallel to the pin rows). Doing this on both sides of the board can reduce the high frequency crosstalk by about 5 dB or 6 dB. As discussed below, power supply bypassing can have a significant impact on crosstalk performance. Driving Capacitive Loads Achieving Low Crosstalk Measured crosstalk from the output of Amplifier 2 to the input of Amplifier 1 of the AD813 is shown in Figure 40. All other crosstalk combinations, (from the output of one amplifier to the input of another), are a few dB better than this due to the additional distance between critical signal nodes. When used with the appropriate output series resistor, any load capacitance can be driven without peaking or oscillation. In most cases, less than 50 Ω is all that is needed to achieve an extremely flat frequency response. As illustrated in Figure 44, the AD813 can be very attractive for driving large capacitive loads. In this case, the AD813’s high output short circuit current allows for a 150 V/µs slew rate when driving a 510 pF capacitor. –10 RL = 150V –20 RF –30 +VS 0.1mF CROSSTALK – dB –40 –50 1.0mF RG –60 4 –70 –80 VIN 11 VO 1.0mF CL RL RT –90 0.1mF –100 –110 100k RS AD813 1M 10M FREQUENCY – Hz –VS 100M Figure 41. Circuit for Driving a Capacitive Load Figure 40. Worst Case Crosstalk vs. Frequency –14– REV. B AD813 CLOSED-LOOP GAIN – dB VS = 65V G = +2 RF = 750V RL = 1kV CL = 10pF 9 RS = 0 6 3 RS = 30V 0 RS = 50V –3 Overload Recovery There are three important overload conditions to consider. They are due to: input common-mode voltage overdrive, output voltage overdrive, and input current overdrive. When the amplifier is configured for low closed-loop gains, and the input common-mode voltage range is exceeded, the recovery time will be very fast, typically under 30 ns. When configured for a higher gain, and overloaded at the output, the recovery time will also be short. For example, in a gain of +10, with 6 dB of input overdrive, the recovery time of the AD813 is about 25 ns (see Figure 45). 1V 1 10 100 FREQUENCY – MHz 50ns 1000 100 90 Figure 42. Response to a Small Load Capacitor at VS = ± 5 V VS = 615V G = +2 RF = 750V RL = 1kV 10 0% CLOSED-LOOP GAIN – dB 2V 9 6 Figure 45. 6 dB Overload Recovery, G = +10, (RL = 500 Ω, RF = 357 Ω, VS = ± 5 V) CL = 150pF, RS = 30V 3 In the case of high gains with very high levels of input overdrive, a longer recovery time will occur. For example, if the input common-mode voltage range is exceeded in the gain of +10, the recovery time will be on the order of 100 ns. This is primarily due to current overloading of the input stage. 0 CL = 510pF, RS = 15V –3 1 10 100 FREQUENCY – MHz 1000 Figure 43. Response to a Large Load Capacitor at VS = ± 15 V 5V 100 As noted in the warning under Maximum Power Dissipation, a high level of input overdrive in a high noninverting gain circuit can result in a large current flow in the input stage. Though this current is internally limited to about 40 mA, its effect on the total power dissipation may be significant. 1 00 n s 100 90 10 0% 5V Figure 44. Circuit of Figure 38 Driving a 510 pF Load Capacitor, VS = ± 15 V (RL = 1 kΩ, RF = RG = 750 Ω, RS =15 Ω) REV. B –15– AD813 High Performance Video Line Driver RG Figures 50 and 51 show the worst case matching; the match between amplifiers 2 and 3 is typically much better than this. RF +VS 0.1mF 75V 75V CABLE 4 75V CABLE 0.2 VOUT AD813 VIN G = +2 RL = 150V NORMALIZED GAIN – dB At a gain of +2, the AD813 makes an excellent driver for a back terminated 75 Ω video line. Low differential gain and phase errors and wide 0.1 dB bandwidth can be realized over a wide range of power supply voltage. Excellent gain and group delay matching are also attainable over the full operating supply voltage range. 615V 0.1 0 –0.1 65V –0.2 3V –0.3 5V –0.4 75V 11 –0.5 0.1mF 75V 100k –VS 0 –90 VS = 615V 65V 3V –180 5V –270 0 –1 2.5 1.5 VS = 615V 5V –3 65V –4 G = +2 RL = 150V 2.0 GAIN MATCHING – dB CLOSED-LOOP GAIN (NORMALIZED) – dB G = +2 RL = 150V –2 3V 1.0 0.5 VS = 615V 0 –0.5 VS = 3V –1.0 –1.5 –5 –2.0 –6 –2.5 1 10 100 1000 1 FREQUENCY – MHz 10 100 FREQUENCY – MHz 1000 Figure 50. Closed-Loop Gain Matching vs. Frequency Figure 47. Closed-Loop Gain & Phase vs. Frequency for the Line Driver 10 120 110 RF = 590V 8 100 RF = 681V 6 90 RF = 750V 4 GROUP DELAY – ns –3dB BANDWIDTH – MHz 100M Figure 49. Fine-Scale Gain (Normalized) vs. Frequency PHASE SHIFT – Degrees +90 PHASE GAIN 10M FREQUENCY – Hz Figure 46. A Video Line Driver Operating at a Gain of +2 (RF = RG from Table I) +1 1M 80 NO PEAKING 70 60 50 2 VS = 3V 5V 65V 615V DELAY 1.0 VS = 615V 0.5 40 0 30 –0.5 20 –1.0 100k 3V DELAY MATCHING 0 2 4 6 8 10 12 14 16 18 20 SUPPLY VOLTAGE – Volts 1M 10M FREQUENCY – Hz 100M Figure 51. Group Delay and Group Delay Matching vs. Frequency, G = +2, RL = 150 Ω Figure 48. –3 dB Bandwidth vs. Supply Voltage for Gain = +2, RL = 150 Ω –16– REV. B AD813 Operation Using a Single Supply Disable Mode Operation The AD813 will operate with total supply voltages from 36 V down to 2.4 V. With proper biasing (see Figure 52) it can make an outstanding single supply video amplifier. Since the input and output voltage ranges extend to within 1 V of the supply rails, it will handle a 1.3 V peak-to-peak signal on a single 3.3 V supply, or a 3 V peak-to-peak signal on a single 5 V supply. The small signal 0.1 dB bandwidths will exceed 10 MHz in either case, and the large signal bandwidths will exceed 6 MHz. Pulling the voltage on any one of the Disable pins about 2.5 V down from the positive supply will put the corresponding amplifier into a disabled, powered down, state. In this condition, the amplifier’s quiescent supply current drops to about 0.5 mA, its output becomes a high impedance, and there is a high level of isolation from input to output. In the case of the gain of two line driver for example, the impedance at the output node will be about the same as for a 1.4 kΩ resistor (the feedback plus gain resistors) in parallel with a 12.5 pF capacitor and the input to output isolation will be about 65 dB at 1 MHz. The capacitively coupled cable driver in Figure 52 will achieve outstanding differential gain and phase errors of 0.05% and 0.05 degrees respectively on a single 5 V supply. Resistor R2, in this circuit, is selected to optimize the differential gain and phase by biasing the amplifier in its most linear region. 619V 619V R3 1kV C3 30mF C2 1mF R1 9kV C1 2mF COUT 75V 47mF 75V CABLE AD813 VIN Input voltages greater than about 1.5 V peak-to-peak will defeat the isolation. In addition, large signals (greater than 3 V peakto-peak) applied to the output node will cause the output impedance to drop significantly. +5V 4 VOUT 75V 11 R2 12.4kV VS = 5V G = +2 RF = 619V RL = 150V CLOSED-LOOP GAIN – dB 0.5 0 –90 –180 0 GAIN –0.5 –270 PHASE SHIFT – Degrees Figure 52. Biasing for Single Supply Operation PHASE Leaving the Disable pin disconnected (floating) will leave the corresponding amplifier operational, in the enabled state. The input impedance of the disable pins is about 35 kΩ in parallel with a few pF. When grounded, about 50 µA flows out of a disable pin on ± 5 V supplies. When the Disable pins are driven by complementary output CMOS logic (such as the 74HC04), the disable time is about 80 ns (until the output goes high impedance) and the enable time is about 100 ns (to low impedance output) on ± 15 V supplies. When operated on ± 15 V supplies, the disable pins should be driven by open drain logic. In this case, pull-up resistors from the disable pins to the plus supply will ensure minimum switching time. 464V 590V +5V 4 6 –1.0 84V 7 –1.5 VIN1 –2.0 5 1 75V –2.5 SELECT1 –3.0 464V –3.5 1 10 100 590V 1000 FREQUENCY – MHz Figure 53. Closed-Loop Gain and Phase vs. Frequency, Circuit of Figure 52 13 VIN2 1V 84V 75V CABLE VOUT 14 50ns 12 75V 2 75V 100 VIN 90 SELECT2 464V 590V 9 84V VOUT 8 10 VIN3 0% 75V 500mV 10 11 3 –5V SELECT3 Figure 54. Pulse Response for the Circuit of Figure 52 with +VS = 5 V REV. B Figure 55. A Fast Switching 3:1 Video Mux (Supply Bypassing Not Shown) –17– AD813 3:1 Video Multiplexer Single Supply Differential Line Driver Wiring the amplifier outputs together will form a 3:1 mux with outstanding gain flatness. Figure 55 shows a recommended configuration which results in –0.1 dB bandwidth of 20 MHz and OFF channel isolation of 60 dB at 10 MHz on ± 5 V supplies. The time to switch between channels is about 180 ns. Switching time is only slightly affected by signal level. Due to its outstanding overall performance on low supply voltages, the AD813 makes possible exceptional differential transmission on very low power. The circuit of Figure 59 will convert a single-ended, ground referenced signal to a differential signal whose common-mode reference is set to one half the supply voltage. This allows for a greater than 2 V peak-to-peak signal swing on a single 3 V power supply. A bandwidth over 30 MHz is achieved with 20 mA of output drive on only 30 mW of quiescent power (excluding load current). 500mV 500ns 100 715V 90 715V VOUT+ 1mF +3V RL1 4 2 +3V 715V 10 0% 1kV 1mF 715V 715V VIN 5V 9kV 1 715V Figure 56. Channel Switching Characteristic for the 3:1 Mux 1mF 715V 1mF 10kV –10 3 VOUT– –20 11 FEEDTHROUGH – dB –30 RL2 –40 715V –50 –60 715V Figure 59. Single 3 V Supply Differential Line Driver with 2 V Swing –70 –80 –90 1V 50ns –100 VIN 100 –110 100k 90 1M 10M 100M FREQUENCY – Hz Figure 57. 3:1 Mux OFF Channel Feedthrough vs. Frequency –45 –90 CLOSED-LOOP GAIN – dB 0.5 –135 –180 0 GAIN VOUT+ – VOUT– 10 PHASE SHIFT – Degrees 0 PHASE 0% 1V Figure 60. Differential Driver Pulse Response (VS = 3 V, RL1 = RL2 = 200 Ω) –0.5 –1.0 –1.5 –2.0 –2.5 –3.0 1 10 FREQUENCY – MHz 100 Figure 58. 3:1 Mux ON Channel Gain and Phase vs. Frequency –18– REV. B AD813 OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 0.795 (20.19) 0.725 (18.42) 14 8 1 7 0.280 (7.11) 0.240 (6.10) 0.060 (1.52) 0.015 (0.38) PIN 1 0.210 (5.33) MAX 0.325 (8.25) 0.300 (7.62) 0.195 (4.95) 0.115 (2.93) 0.130 (3.30) MIN 0.160 (4.06) 0.115 (2.93) 0.022 (0.558) 0.014 (0.356) 0.015 (0.381) 0.008 (0.204) SEATING PLANE 0.100 0.070 (1.77) (2.54) 0.045 (1.15) BSC C1860b–0–5/98 14-Lead Plastic DIP (N-14) 14-Lead SOIC (R-14) 0.3444 (8.75) 0.3367 (8.55) 0.1574 (4.00) 0.1497 (3.80) 14 8 1 7 PIN 1 0.0098 (0.25) 0.0040 (0.10) 0.0688 (1.75) 0.0532 (1.35) 0.0192 (0.49) 0.0138 (0.35) 0.0099 (0.25) 0.0075 (0.19) 0.0196 (0.50) x 45 0.0099 (0.25) 8 0 0.0500 (1.27) 0.0160 (0.41) PRINTED IN U.S.A. 0.0500 SEATING (1.27) PLANE BSC 0.2440 (6.20) 0.2284 (5.80) REV. B –19–