AD816AVR

a FEATURES Flexible Configuration Two Low Noise Voltage Feedback Amplifiers with High Current Drive, Ideal for ADSL Receivers or Drivers for Low Impedance Loads such as CRT Coils Two High Current Drive Amplifiers, Ideal for an ADSL Differential Driver or Single Ended Drivers for Low Impedance Loads such as CRT Coils Thermal Overload Protection CURRENT FEEDBACK AMPLIFIERS/DRIVERS High Output Drive 26 dBm Differential Line Drive for ADSL Transmitters 40 V p-p Differential Output Voltage, RL = 50 @ 1 MHz 500 mA Continuous Current, R L = 5 1 A Peak Current, 1% Duty Cycle, RL = 15 for DMT Low Distortion –68 dB @ 1 MHz THD, RL = 100 , V O = 40 V p-p High Speed 120 MHz Bandwidth (–3 dB) 1500 V/ s Differential Slew Rate, VO = 10 V p-p, G = +5 70 ns Settling Time to 0.1% VOLTAGE FEEDBACK AMPLIFIERS/RECEIVERS High Input Performance 4 nV/√Hz Voltage Noise 15 mV Max Input Offset Voltage Low Distortion –68 dB @ 1 MHz THD, VO = 10 V p-p, RL = 200 High Speed 100 MHz Bandwidth (–3 dB) 180 V/ s Slew Rate High Output Drive 70 mA Output Current Drive APPLICATIONS ADSL, VDSL and HDSL Line Interface Driver and Receiver CRT Convergence and Astigmatism Adjustment Coil and Transformer Drivers Composite Audio Amplifiers PRODUCT DESCRIPTION 500 mA Differential Driver and Dual Low Noise (VF) Amplifiers AD816* FUNCTIONAL BLOCK DIAGRAM RECEIVER B 15 14 13 12 11 B 10 9 +VS 8 –VS 7 6 5 4 3 2 1 NC OUT2 RECEIVER –IN2 RECEIVER +IN2 RECEIVER +IN2 DRIVER –IN2 DRIVER OUT2 DRIVER +VS –VS OUT1 DRIVER –IN1 DRIVER +IN1 DRIVER +IN1 RECEIVER –IN1 RECEIVER OUT1 RECEIVER TAB IS +VS DRIVER A & B AD816 A RECEIVER A NC = NO CONNECT The two high output drive amplifiers are capable of supplying a minimum of 500 mA continuous output current and up to 1A peak output current, and when configured differentially, 40 V p-p differential output swing can be achieved on ± 15 V supplies into a load of 50 Ω. The drivers have 120 MHz of bandwidth and 1,500 V/µs of differential slew rate while featuring total harmonic distortion of –68 dB at 1 MHz into a 100 Ω load, specifications required for high frequency telecommunication subscriber line drivers. The low noise voltage feedback amplifiers are fully independent and can be configured differentially for use as receiver amplifiers within a subscriber line hybrid interface or individually for signal conditioning or filtering. The low noise of 4 nV/√Hz and distortion of –68 dB at 1 MHz enable low level signals to be resolved and amplified in the presence of large common-mode voltages. 100 MHz of bandwidth and 180 V/µs of slew rate combined with a load drive capability of 70 mA enable these amplifiers to drive passive filters and low inductance coils. The AD816 has thermal overload protection for system reliability and is available in low thermal resistance power packages. The AD816 operates over the industrial temperature range (–40°C to +85°C). The AD816 consists of two high current drive and two low noise amplifiers. These can be configured differentially for driving low impedance loads and receiving signals over twisted pair cable or could be used independently for single ended driving application such as correction circuits within high resolution CRT Monitors. R EV. 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., 1999 AD816–SPECIFICATIONS DRIVER AMPLIFIERS (@ T = +25 C, V = A S 15 V dc, RF = 1 k and RLOAD = 50 unless otherwise noted) VS ± 15 ±5 ± 15 ± 15 ± 15 ± 15 ± 5, ± 15 ± 5, ± 15 ± 5, ± 15 ± 15 ± 15 ±5 ± 15 Min AD816A Typ Max Units Model DYNAMIC PERFORMANCE Small Signal Bandwidth (–3 dB) Conditions G = +2, RF = 499 Ω, VIN = 0.125 V rms, RL = 100 Ω G = +2, RF = 499 Ω, VIN = 0.125 V rms, RL = 100 Ω G = +2, RF = 499 Ω, VIN = 0.125 V rms, RL = 100 Ω VOUT = 10 V p-p, G = +5, RL = 100 Ω 10 V Step, G = +2 f = 1 MHz, RLOAD = 100 Ω, VOUT = 40 V p-p f = 10 kHz, G = +2 (Single Ended) f = 10 kHz, G = +2 f = 10 kHz, G = +2 NTSC, G = +2, RLOAD = 25 Ω NTSC, G = +2, RLOAD = 25 Ω 100 90 120 110 10 1500 70 –68 1.85 1.8 19 0.05 0.45 5 10 40 0.5 5 20 2 10 12 15 25 2 5 60 100 5 5 50 50 MHz MHz MHz V/µs ns dBc nV/√Hz pA/√Hz pA/√Hz % Degrees mV mV mV µV/°C mV mV µV/°C µA µA µA µA µA µA MΩ MΩ MΩ Ω pF ±V ±V dB dB V p-p V p-p V p-p V p-p mA mA A A Bandwidth (0.1 dB) Differential Slew Rate Settling Time to 0.1% NOISE/HARMONIC PERFORMANCE Total Harmonic Distortion (Differential) Input Voltage Noise Input Current Noise (+I IN) Input Current Noise (–I IN) Differential Gain Error Differential Phase Error DC PERFORMANCE Input Offset Voltage 1400 TMIN to TMAX Input Offset Voltage Drift Differential Offset Voltage TMIN to TMAX Differential Offset Voltage Drift –Input Bias Current TMIN to TMAX +Input Bias Current TMIN to TMAX Differential Input Bias Current Open-Loop Transresistance INPUT CHARACTERISTICS Differential Input Resistance Differential Input Capacitance Input Common-Mode Voltage Range Common-Mode Rejection Ratio Differential Common-Mode Rejection Ratio OUTPUT CHARACTERISTICS Voltage Swing TMIN to TMAX TMIN to TMAX Single Ended, R LOAD = 25 Ω Differential, R LOAD = 50 Ω TMIN to TMAX RLOAD = 5 Ω 10 µs Pulse, 1% Duty Cycle, RL = 15 Ω Note 1 TMIN to TMAX VOUT = ± 10 V, RL = 1 kΩ TMIN to TMAX +Input –Input ± 5, ± 15 ± 5, ± 15 ± 5, ± 15 ± 5, ± 15 ± 15 ± 15 ± 15 ±5 ± 5, ± 15 ± 5, ± 15 ± 15 ±5 ± 15 ± 15 ± 15 ±5 ± 15 ± 15 0.7 0.6 ± 5, ± 15 2 56 80 23 2.2 46 45 500 200 7 15 1.4 13.5 3.5 60 100 24.5 3.6 49 750 100 1.0 1.0 Continuous Output Current Peak Output Current Short Circuit Current NOTES 1 See Power Considerations section. Specifications subject to change without notice. –2– REV. B AD816 RECEIVER AMPLIFIERS (@ T = +25 C, V A S = 15 V dc, RF = 1 k and RLOAD = 500 VS unless otherwise noted) Min AD816A Typ Max Units Model Conditions DYNAMIC PERFORMANCE Small Signal Bandwidth (–3 dB) Bandwidth (0.1 dB) Slew Rate Settling Time to 0.1% NOISE/HARMONIC PERFORMANCE Total Harmonic Distortion Input Voltage Noise Current Noise Differential Gain Error Differential Phase Error DC PERFORMANCE Input Offset Voltage G = +2, RL = 100 Ω G = +2, RL = 100 Ω G = +2 G = +2 VOUT = 4 V p-p VOUT = 10 V p-p Step, G = +2 f = 1 MHz, RLOAD = 200 Ω f = 10 kHz f = 10 kHz NTSC, G = +2, RLOAD = 150 Ω NTSC, G = +2, RLOAD = 150 Ω ± 15 ±5 ± 15 ±5 ± 15 ± 15 ± 15 ± 5, ± 15 ± 5, ± 15 ± 15 ±5 ± 15 ±5 ± 5, ± 15 100 80 30 40 180 45 –68 4 2 0.04 0.05 0.03 0.06 7.5 20 5 0.5 1 6 MHz MHz MHz MHz V/µs ns dBc nV/√Hz pA/√Hz % % Degrees Degrees mV mV µV/°C µA µA µA nA/°C V/mV V/mV kΩ pF V V V V dB V p-p V p-p V p-p V p-p mA mA 0.08 0.1 0.1 0.1 15 15 7 15 2 TMIN to TMAX Offset Voltage Drift Input Bias Current TMIN to TMAX Input Offset Current Offset Current Drift Open-Loop Gain INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range VOUT = ± 7.5 V, RLOAD = 150 Ω TMIN to TMAX ± 5, ± 15 ± 5, ± 15 ± 15 ± 15 3 1 Common-Mode Rejection Ratio OUTPUT CHARACTERISTICS Output Voltage Swing VCM = ± 5 V Single Ended, RLOAD = 150 Ω TMIN to TMAX Single Ended, RLOAD = 150 Ω TMIN to TMAX RL = 150 Ω ± 15 ± 15 ±5 ±5 ± 15 ± 15 ± 15 ±5 ±5 ± 15 ± 15 +13 –12 +3.8 –2.7 82 25.2 25.2 6.2 6.0 65 300 1.5 +14.3 –13.4 +4.3 –3.4 110 25.5 6.4 70 105 Output Current Short Circuit Current Specifications subject to change without notice. COMMON CHARACTERISTICS unless otherwise noted) Model MATCHING CHARACTERISTICS Crosstalk: Driver to Driver Drivers to Receivers Receiver to Receiver POWER SUPPLY Operating Range Quiescent Current Driver Supply Rejection Ratio Receiver Supply Rejection Ratio Specifications subject to change without notice. (@ TA = +25 C, VS = 15 V dc, RF = 1 k and RLOAD = 50 (Driver), RLOAD = 500 AD816A Typ Max (Receiver) Conditions VS Min Units f = 1 MHz, VIN = 200 mV rms, RLOAD = 100 Ω ± 15 f = 1 MHz, VIN = 200 mV rms, RLOAD = 100 Ω ± 15 f = 1 MHz, VIN = 200 mV rms, RLOAD = 500 Ω ± 15 ±5 –67 –64 –81 ± 18 56 59 dB dB dB V mA mA dB dB TMIN to TMAX TMIN to TMAX TMIN to TMAX ± 15 ± 15 ± 15, ± 5 ± 15, ± 5 46 –49 –69 –66 –75 REV. B –3– AD816 Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V Total Internal Power Dissipation2 Plastic (Y, YS and VR) . . 3.05 W (Observe Derating Curves) Input Voltage (Common Mode) . . . . . . . . . . . . . . . . . . . . ± VS Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . ± 6 V Output Short Circuit Duration . . . . . . . . . . . . . . . . . . . . . . Observe Power Derating Curves Storage Temperature Range Y, YS, VR Package . . . . . . . . . . . . . . . . . . –65°C to +125°C Operating Temperature Range AD816A . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C Lead Temperature Range (Soldering, 10 sec) . . . . . . . +300°C 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: 15-Lead Through Hole and Surface Mount: θJA = 41°C/W. ABSOLUTE MAXIMUM RATINGS 1 MAXIMUM POWER DISSIPATION The maximum power that can be safely dissipated by the AD816 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. The AD816 has thermal shutdown protection, which guarantees that the maximum junction temperature of the die remains below a safe level. However, shorting the output to ground or either power supply for an indeterminate period will result in device failure. To ensure proper operation, it is important to observe the derating curves and refer to the section on power considerations. It must also be noted that in high (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. 14 MAXIMUM POWER DISSIPATION – Watts PIN CONFIGURATION Y-15 VR-15, YS-15 13 12 11 10 9 8 7 6 5 4 3 2 1 TJ = 150 C θJA = 16 C/W SOLDERED DOWN TO COPPER HEAT SINK AREA (STILL AIR = 0FT/MIN) AD816 AVR, AY TOP VIEW TOP VIEW 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 θJA = 41 C/W (STILL AIR = 0FT/MIN) NO HEAT SINK AD816 AVR, AY OUT1 RECEIVER –IN1 RECEIVER +IN1 RECEIVER +IN1 DRIVER –IN1 DRIVER OUT1 DRIVER –VS +VS OUT2 DRIVER –IN2 DRIVER +IN2 DRIVER +IN2 RECEIVER –IN2 RECEIVER OUT2 RECEIVER NC OUT1 RECEIVER –IN1 RECEIVER +IN1 RECEIVER +IN1 DRIVER –IN1 DRIVER OUT1 DRIVER –VS +VS OUT2 DRIVER –IN2 DRIVER +IN2 DRIVER +IN2 RECEIVER –IN2 RECEIVER OUT2 RECEIVER NC 0 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 AMBIENT TEMPERATURE – C 70 80 90 Figure 1. Plot of Maximum Power Dissipation vs. Temperature (Copper Heat Sink Area = 2 in.2) ORDERING GUIDE Package Option Y-15 YS-15 VR-15 Model AD816AY AD816AYS AD816AVR Temperature Range –40°C to +85°C –40°C to +85°C –40°C to +85°C Package Description 15-Lead Through-Hole SIP with Staggered Leads and 90° Lead Form 15-Lead Through-Hole SIP with Staggered Leads and Straight Lead Form 15-Lead Surface Mount DDPAK 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 AD816 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 –4– REV. B Typical Driver Performance Characteristics–AD816 30 SINGLE-ENDED OUTPUT VOLTAGE – Volts p-p 60 VS = 15V 50 DIFFERENTIAL OUTPUT VOLTAGE – Volts p-p 60 –IB, VS = 50 15V 25 20 40 INPUT BIAS CURRENT – A 40 15 30 30 –IB, VS = 20 5V 10 VS = 5 5V 20 10 10 +IB, VS = 0 –40 –20 0 20 40 60 JUNCTION TEMPERATURE – C 5V, 80 15V 100 0 10 100 LOAD RESISTANCE – (Differential – 1k ) (Single-Ended – 0 10k /2) Figure 2. Driver Output Voltage Swing vs. Load Resistance Figure 5. Driver Input Bias Current vs. Temperature 100 100 –40 TOTAL HARMONIC DISTORTION – dBc –50 –60 –70 –80 –90 –100 –110 100 VOLTAGE NOISE – nV/ Hz INVERTING INPUT CURRENT NOISE CURRENT NOISE – pA/ Hz VS = 15V G = +10 VOUT = 40V p-p 50 100 10 10 RL = 50 (DIFFERENTIAL) 400 NONINVERTING INPUT CURRENT NOISE RL = 200 (DIFFERENTIAL) 1 10 INPUT VOLTAGE NOISE 100 1k FREQUENCY – Hz 10k 1 100k 1k 10k 100k FREQUENCY – Hz 1M 10M Figure 3. Driver Input Current and Voltage Noise vs. Frequency Figure 6. Driver Total Harmonic Distortion vs. Frequency 0 –10 –20 –30 PSRR – dB 80 COMMON-MODE REJECTION – dB VS = 15V G = +2 RL = 100 70 60 50 1k 40 1k 30 20 10 10k VIN 1k 1k VOUT VS = 15V –40 –50 –60 –70 –80 –90 –PSRR +PSRR –100 0.01 0.1 1 10 FREQUENCY – MHz 100 300 100k 1M FREQUENCY – Hz 10M 100M Figure 4. Driver Power Supply Rejection vs. Frequency Figure 7. Driver Common-Mode Rejection vs. Frequency REV. B –5– AD816–Typical Driver Performance Characteristics 1400 –SR SINGLE-ENDED SLEW RATE – V/ s (PER AMPLIFIER) 2800 G = +5 RL = 100 2400 2000 1600 +SR 1200 800 400 0 0 5 10 15 OUTPUT STEP SIZE – V p-p 20 80 TA = +25 C DIFFERENTIAL SLEW RATE – V/ s 1200 1000 800 600 400 200 0 60 VS = 40 RTI OFFSET – mV VS = 20 0 –20 –40 –60 –2.0 –1.6 –1.2 VIN f = 0.1Hz 100 49.9 1k 0 –0.8 –0.4 0.4 0.8 LOAD CURRENT – Amps 1k SINGLE DRIVER VOUT RL= 5 VS = 15V 5V DIFFERENTIAL SR 10V 1.2 1.6 2.0 Figure 8. Driver Slew Rate vs. Output Step Size Figure 11. Driver Thermal Nonlinearity vs. Output Current Drive 15 TA = +25 C 10 VS = 5V VS = 15V VS = 10V DIFFERENTIAL OUTPUT VOLTAGE – V p-p 40 TA = +25 C VS = 15V RL = 100 RTI OFFSET – mV 5 30 RL = 50 20 RL = 25 10 RL = 1 0 0 2 4 10 6 8 FREQUENCY – MHz 12 14 0 VIN f = 0.1Hz 100 49.9 SINGLE DRIVER –5 VOUT RL= 25 –10 1k 1k –15 –20 –16 –12 –8 –4 0 4 VOUT – Volts 8 12 16 20 Figure 9. Driver Gain Nonlinearity vs. Output Voltage Figure 12. Driver Large Signal Frequency Response 100 100 90 CLOSED-LOOP OUTPUT RESISTANCE – 10 VS = 5V 1 VS = 15V 0.1 10 0% 5V 1s 0.01 30k 100k 300k 1M 3M 10M FREQUENCY – Hz 30M 100M 300M Figure 10. Driver 40 V p-p Differential Sine Wave; RL = 50 Ω, f = 100 kHz Figure 13. Driver Closed-Loop Output Resistance vs. Frequency –6– REV. B Typical Driver Characteristics–AD816 DIFF PHASE – Degrees 6 BACK TERMINATED LOADS (25 ) 0.04 0.03 0.02 0.01 0.00 –0.01 –0.02 –0.03 –0.04 0.5 0.4 0.3 0.2 0.1 0.0 –0.1 –0.2 –0.3 0.12 0.10 0.08 0.06 0.04 0.02 0.00 –0.02 –0.04 DIFF GAIN – % 0 –3 –6 INPUT LEVEL – dBV PHASE –9 –12 –15 –18 –21 –24 –27 100k VIN = 62.5mVrms VIN = 125mVrms VIN = 0.25Vrms –3 –6 –9 –12 –15 –18 –21 300M GAIN 1 2 3 4 5 6 7 8 9 10 11 0.010 0.005 0.000 –0.005 PHASE –0.010 –0.015 GAIN –0.020 –0.025 –0.030 1 2 G = +2 RF = 1k NTSC DIFF PHASE – Degrees 2 BACK TERMINATED LOADS (75 ) DIFF GAIN – % 3 4 5 6 7 8 9 10 11 1M 10M FREQUENCY – Hz 100M Figure 14. Driver Differential Gain and Differential Phase (Per Amplifier) Figure 17. Driver Small and Large Signal Frequency Response, G = +2 0 VIN = 200mVrms –10 –20 CROSSTALK – dB INPUT 100 50 DRIVER A OUTPUT OUTPUT 100 499 499 100 499 499 DRIVER 100 B 2 RF = 499 INPUT 50 1 0 –30 –40 –50 –60 –70 –80 –90 NORMALIZED FLATNESS – dB VIN = 50mVrms G +5 RL = 100 RS = 100 0.1 0 –0.1 RF = 604 RF = 750 –1 –2 –3 –4 –5 DRIVER A = INPUT DRIVER B = OUTPUT RF = 604 RF = 750 DRIVER B = INPUT DRIVER A = OUTPUT –0.2 –0.3 –0.4 100k 1M 10M FREQUENCY – Hz 100M –6 –7 –8 300M –100 10k 100k 1M 10M FREQUENCY – Hz 100M 300M Figure 15. Driver Output-to-Output Crosstalk vs. Frequency Figure 18. Driver Frequency Response and Flatness, G = +5 3 VIN = 1.0Vrms 0 –3 VIN = 0.5Vrms –6 –9 VIN = 0.25Vrms –12 –15 –18 –21 –24 –27 100k VIN = 62.5mVrms VIN = 125mVrms NORMALIZED FREQUENCY RESPONSE – dB OUTPUT/INPUT LEVEL – dBV G = +1 RF = 499 RL = 100 RS = 100 3 2 1 0 –1 –2 –3 –4 –5 –6 –7 100k 1M 10M FREQUENCY – Hz 100M 300M RF = 604 RF = 750 VIN = 200mVrms G +2 RL = 100 RS = 100 RF = 499 1M 10M FREQUENCY – Hz 100M 300M Figure 16. Driver Small and Large Signal Frequency Response, G = +1 Figure 19. Driver Frequency Response vs. RF, G = +2 REV. B –7– NORMALIZED FREQUENCY RESPONSE – dB OUTPUT LEVEL – dBV G = +2 RF = 1k NTSC VIN = 0.5Vrms G = +2 RF = 499 RL = 100 RS = 100 6 3 0 AD816–Typical Driver Performance Characteristics 1k +15V 10 F 0.1 F 1k VIN PULSE GENERATOR TR/TF = 250ps 55 100 499 8 8 499 +15V 10 F 0.1 F AD816 DRIVER A/B 0.1 F 7 AD816 100 DRIVER A/B 7 RL = 100 VIN PULSE GENERATOR TR/TF = 500ps 50 0.1 F 10 F RL = 100 10 F –15V –15V Figure 20. Test Circuit Gain = –1 Figure 24. Driver Test Circuit, Gain = +2 Figure 21. Driver 500 mV Step Response, G = –1 Figure 25. 10 V Step Response, G = +2 Figure 22. Driver 4 V Step Response, G = –1 Figure 26. Driver 400 mV Step Response, G = +2 RF +15V 10 F 0.1 F RG 8 AD816 VIN PULSE GENERATOR TR/TF = 250ps 100 50 –15V DRIVER A/B 0.1 F 7 RL = 100 10 F Figure 23. Test Circuit, Gain = 1 + RF/RG Figure 27. Driver 20 V Step Response, G = +5 –8– REV. B Typical Receiver Performance Characteristics–AD816 50 –40 G = +5 VOUT = 14V p-p RF = 4k RL = 1k INPUT VOLTAGE NOISE – nV/ Hz 40 HARMONIC DISTORTION – dB –50 –60 30 –70 20 –80 10 –90 0 3 10 100 1k 10k 100k FREQUENCY – Hz 1M 10M –100 100 1k 10k 100k FREQUENCY – Hz 1M 10M Figure 28. Receiver Input Voltage Noise Spectral Density Figure 31. Receiver Harmonic Distortion vs. Frequency 5 4 3 2 VIN 1k 1k VOUT 50 3 VIN = 1.0Vrms 0 –3 VIN = 0.5Vrms INPUT LEVEL – dBV VS = 15V 9 G = +2 RF = 1k CF = 2.2pF RL = 100 RS = 0 6 OUTPUT LEVEL (RTO) – dBV 3 0 –3 100 –6 –9 –12 –15 VIN = 0.125Vrms –18 –21 VIN = 0.0625Vrms –24 –27 100k 1M 10M FREQUENCY – Hz VIN = 0.25Vrms GAIN – dB 1 0 –1 –2 –3 –4 –5 100k 1M 10M FREQUENCY – Hz 100M 300M VS = 5V –6 –9 –12 –15 –18 100M –21 300M Figure 29. Receiver Closed-Loop Gain vs. Frequency, Gain = –1 Figure 32. Receiver Small and Large Signal Frequency Response, Gain = +2 100 100 90 80 80 70 CMR – dB PSR – dB 60 50 40 30 NEGATIVE SUPPLY 60 1k VIN 40 1k 1k 1k VOUT POSITIVE SUPPLY 20 0 1k 10k 100k FREQUENCY – Hz 1M 10M 10 100 1k 10k 100k 1M FREQUENCY – Hz 10M 100M Figure 30. Receiver Common-Mode Rejection vs. Frequency Figure 33. Receiver Power Supply Rejection vs. Frequency REV. B –9– AD816–Typical Receiver Performance Characteristics 2.2pF 1k +15V 0.1 F 1k 8 1k +15V 0.1 F 1k VIN VOUT 8 10 F 10 F AD816 REC A/B VIN PULSE GENERATOR TR/ TF = 500ps 50 –15V 7 PULSE GENERATOR TR/ TF = 250ps 50 AD816 REC A/B 7 VOUT 0.1 F 10 F RL = 500 0.1 F 10 F RL –15V Figure 34. Test Circuit, Gain = +2 Figure 38. Test Circuit, Gain = –1 50ns 5V Figure 35. Receiver 10 V Step Response, G = +2 Figure 39. Receiver 10 V Step Response, G = –1 50ns Figure 36. Receiver 400 mV Step Response, G = +2 Figure 40. Receiver 400 mV Step Response, G = –1 0 –10 –20 CROSSTALK – dB 0 VIN = 200mVrms INPUT 50 REC A OUTPUT OUTPUT REC B 50 INPUT INPUT 100 DRV A REC A OUTPUT OUTPUT 100 100 1k INPUT 50 VIN = 200mVrms –10 –20 –30 CROSSTALK – dB 50 499 499 –30 –40 –50 –60 –70 –80 –90 1k 2.2pF 2.2pF 499 499 OUTPUT OUTPUT 100 100 1k 1k 1k 100 100 1k 1k 1k –40 –50 –60 –70 –80 INPUT 100 INPUT 50 2.2pF 2.2pF DRV B REC B 50 RECEIVER B : INPUT RECEIVER A : OUTPUT DRIVER A: INPUT RECEIVER A: OUTPUT DRIVER A: INPUT RECEIVER B: OUTPUT DRIVER B: INPUT RECEIVER A: OUTPUT RECEIVER A = INPUT RECEIVER B = OUTPUT 0.1 1 10 FREQUENCY – MHz 100 300 –90 –100 0.01 DRIVER B: INPUT RECEIVER A: OUTPUT –100 0.01 0.1 1 10 FREQUENCY – MHz 100 300 Figure 37. Receiver Output-to-Output Crosstalk vs. Frequency Figure 41. Driver-to-Receiver Crosstalk vs. Frequency –10– REV. B AD816 THEORY OF OPERATION (DRIVER) Table I. Driver Resistor Values The AD816 driver is a dual current feedback amplifier with high (500 mA) output current capability. Being a current feedback amplifier, the AD816 driver’s open-loop behavior is expressed as transimpedance, ∆VO/∆I–IN, or TZ. The open-loop transimpedance behaves just as the open-loop voltage gain of a voltage feedback amplifier, that is, it has a large dc value and decreases at roughly 6 dB/octave in frequency. Since RIN is proportional to 1/gM, the equivalent voltage gain is just TZ × gM, where the gM in question is the transconductance of the input stage. Figure 42 shows the driver connected as a follower with gain. Basic analysis yields the following results: T Z (S ) VO =G× VIN T Z (S ) + G × RIN + RF RF ( ) G = +1 –1 +2 +5 +10 604 499 499 499 1k RG ( ) ∞ 499 499 125 110 DRIVER DC ERRORS AND NOISE where: G = 1+ RF RG RIN = 1/gM ≈ 25 Ω RF RG RIN RN VIN VOUT There are three major noise and offset terms to consider in a current feedback amplifier. For offset errors refer to the equation below. For noise error the terms are root-sum-squared to give a net output error. In the circuit below (Figure 43), they are input offset (VIO) which appears at the output multiplied by the noise gain of the circuit (1 + RF/RG), noninverting input current (IBN × RN) also multiplied by the noise gain, and the inverting input current, which when divided between RF and RG and subsequently multiplied by the noise gain always appear at the output as IBI × RF. The input voltage noise of the AD816 is less than 4 nV/√Hz. At low gains, however, the inverting input current noise times RF is the dominant noise source. Careful layout and device matching contribute to better offset and drift. The typical performance curves in conjunction with the equations below can be used to predict the performance of the AD816 in any application.  R  R VOUT = VIO  1 + F  ± I BN RN  1 + F  ± I BI RF  RG   RG  RF RG VIO I BI Figure 42. Current-Feedback Amplifier Operation Recognizing that G × RIN