High Speed, Low Cost, Op Amp ADA4860-1 PIN CONFIGURATION High speed 800 MHz, −3 dB bandwidth 790 V/μs slew rate 8 ns settling time to 0.5% Wide supply range: 5 V to 12 V Low power: 6 mA 0.1 dB flatness: 125 MHz Differential gain: 0.02% Differential phase: 0.02° Low voltage offset: 3.5 mV (typ) High output current: 25 mA Power down VOUT 1 –VS 2 +IN 3 + – 6 +VS 5 POWER DOWN 4 –IN 05709-001 FEATURES Figure 1. 6-Lead SOT-23 (RJ-6) APPLICATIONS Consumer video Professional video Broadband video ADC buffers Active filters GENERAL DESCRIPTION The ADA4860-1 is available in a 6-lead SOT-23 package and is designed to work over the extended temperature range of −40°C to +105°C. G = +2 6.2 VOUT = 2V p-p RF = RG = 499Ω 6.1 6.0 5.9 VS = +5V 5.8 VS = ±5V 5.7 5.6 5.5 05709-003 The ADA4860-1 is designed to operate on supply voltages as low as +5 V and up to ±5 V using only 6 mA of supply current. To further reduce power consumption, the amplifier is equipped with a power-down feature that lowers the supply current to 0.25 mA. 6.3 CLOSED-LOOP GAIN (dB) The ADA4860-1 is a low cost, high speed, current feedback op amp that provides excellent overall performance. The 800 MHz, −3 dB bandwidth, and 790 V/μs slew rate make this amplifier well suited for many high speed applications. With its combination of low price, excellent differential gain (0.02%), differential phase (0.02°), and 0.1 dB flatness out to 125 MHz, this amplifier is ideal for both consumer and professional video applications. 5.4 5.3 0.1 1 10 100 1000 FREQUENCY (MHz) Figure 2. 0.1 dB Flatness 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 that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved. ADA4860-1 TABLE OF CONTENTS Features .............................................................................................. 1 Power Supply Bypassing ............................................................ 14 Applications....................................................................................... 1 Feedback Resistor Selection...................................................... 14 Pin Configuration............................................................................. 1 Driving Capacitive Loads.......................................................... 15 General Description ......................................................................... 1 Power Down Pin......................................................................... 15 Revision History ............................................................................... 2 Video Amplifier.......................................................................... 15 Specifications..................................................................................... 3 Single-Supply Operation ........................................................... 15 Absolute Maximum Ratings............................................................ 5 Optimizing Flatness and Bandwidth ....................................... 16 Thermal Resistance ...................................................................... 5 Layout and Circuit Board Parasitics ........................................ 17 ESD Caution.................................................................................. 5 Outline Dimensions ....................................................................... 18 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 18 Application Information................................................................ 14 REVISION HISTORY 4/06—Revision 0: Initial Version Rev. 0 | Page 2 of 20 ADA4860-1 SPECIFICATIONS VS = +5 V (@ TA = 25°C, G = +2, RL = 150 Ω referred to midsupply, CL = 4 pF, unless otherwise noted). For G = +2, RF = RG = 499 Ω and for G = +1, RF = 550 Ω. Table 1. Parameter DYNAMIC PERFORMANCE –3 dB Bandwidth Bandwidth for 0.1 dB Flatness +Slew Rate (Rising Edge) −Slew Rate (Falling Edge) Settling Time to 0.5% NOISE/DISTORTION PERFORMANCE Harmonic Distortion HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase DC PERFORMANCE Input Offset Voltage +Input Bias Current −Input Bias Current Open-Loop Transresistance INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range Common-Mode Rejection Ratio POWER DOWN PIN Input Voltage Bias Current Turn-On Time Turn-Off Time OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range Total Quiescent Current Quiescent Current Power Supply Rejection Ratio +PSR Conditions Min Typ Max Unit VO = 0.2 V p-p VO = 2 V p-p VO = 0.2 V p-p, RL = 75 Ω G = +1, VO = 0.2 V p-p VO = 2 V p-p VO = 2 V p-p, RL = 75 Ω VO = 2 V p-p VO = 2 V p-p VO = 2 V step 460 165 430 650 58 45 695 560 8 MHz MHz MHz MHz MHz MHz V/μs V/μs ns fC = 1 MHz, VO = 2 V p-p fC = 5 MHz, VO = 2 V p-p f = 100 kHz f = 100 kHz, +IN/−IN RL = 150 Ω RL = 150 Ω −90/−102 −70/−76 4.0 1.5/7.7 0.02 0.03 dBc dBc nV/√Hz pA/√Hz % Degrees −13 −2 −7 400 −4.25 −1 +1.0 650 −52 10 85 1.5 1.2 to 3.7 −56 MΩ Ω pF V dB Enabled Power down Enabled Power down 0.5 1.8 −200 60 200 3.5 V V nA μA ns μs VIN = +2.25 V to −0.25 V RL = 75 Ω RL = 150 Ω RL = 1 kΩ Sinking and sourcing 60/100 1.2 to 3.8 1 to 4 0.8 to 4.2 45 ns V V V mA +IN −IN +IN VCM = 2 V to 3 V Enabled POWER DOWN pin = +VS +VS = 4 V to 6 V, −VS = 0 V Rev. 0 | Page 3 of 20 1.2 to 3.8 0.9 to 4.1 5 4.5 −60 5.2 0.2 −62 +13 +1 +10 12 6.5 0.5 mV μA μA kΩ V mA mA dB ADA4860-1 VS = ±5 V (@ TA = 25°C, G = +2, RL = 150 Ω, CL = 4 pF, unless otherwise noted). For G = +2, RF = RG = 499 Ω and for G = +1, RF = 550 Ω. Table 2. Parameter DYNAMIC PERFORMANCE –3 dB Bandwidth Bandwidth for 0.1 dB Flatness +Slew Rate (Rising Edge) −Slew Rate (Falling Edge) Settling Time to 0.5% NOISE/DISTORTION PERFORMANCE Harmonic Distortion HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase DC PERFORMANCE Input Offset Voltage +Input Bias Current −Input Bias Current Open-Loop Transresistance INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range Common-Mode Rejection Ratio POWER DOWN PIN Input Voltage Bias Current Turn-On Time Turn-Off Time OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range Total Quiescent Current Quiescent Current Power Supply Rejection Ratio +PSR −PSR Conditions Min Typ Max Unit VO = 0.2 V p-p VO = 2 V p-p VO = 0.2 V p-p, RL = 75 Ω G = +1, VO = 0.2 V p-p VO = 2 V p-p VO = 2 V p-p, RL = 75 Ω VO = 2 V p-p VO = 2 V p-p VO = 2 V step 520 230 480 800 125 70 980 790 8 MHz MHz MHz MHz MHz MHz V/μs V/μs ns fC = 1 MHz, VO = 2 V p-p fC = 5 MHz, VO = 2 V p-p f = 100 kHz f = 100 kHz, +IN/−IN RL = 150 Ω RL = 150 Ω −90/−102 −77/−94 4.0 1.5/7.7 0.02 0.02 dBc dBc nV/√Hz pA/√Hz % Degrees −13 −2 −7 400 −3.5 −1.0 +1.5 700 −55 12 90 1.5 −3.8 to +3.7 −58 MΩ Ω pF V dB Enabled Power down Enabled Power down −4.4 −3.2 −250 130 200 3.5 V V nA μA ns μs VIN = ±3.0 V RL = 75 Ω RL = 150 Ω RL = 1 kΩ Sinking and sourcing 45/90 ±2 ±3.1 ±4.1 85 ns V V V mA +IN −IN +IN VCM = ±2 V Enabled POWER DOWN pin = +VS +VS = +4 V to +6 V, −VS = −5 V +VS = +5 V, −VS = −4 V to −6 V, POWER DOWN pin = −VS Rev. 0 | Page 4 of 20 ±2.5 ±3.9 5 5 −62 −58 6 0.25 −64 −61 +13 +1 +10 12 8 0.5 mV μA μA kΩ V mA mA dB dB ADA4860-1 ABSOLUTE MAXIMUM RATINGS Table 3. The power dissipated in the package (PD) for a sine wave and a resistor load is the total power consumed from the supply minus the load power. Rating 12.6 V See Figure 3 −VS + 1 V to +VS − 1 V ±VS −65°C to +125°C −40°C to +105°C JEDEC J-STD-20 150°C PD = Total Power Consumed − Load Power ( VOUT 2 RL RMS output voltages should be considered. 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. Airflow across the ADA4860-1 helps remove heat from the package, effectively reducing θJA. In addition, more metal directly in contact with the package leads and through holes under the device reduces θJA. Figure 3 shows the maximum safe power dissipation in the package vs. the ambient temperature for the 6-lead SOT-23 (170°C/W) on a JEDEC standard 4-layer board. θJA values are approximations. THERMAL RESISTANCE Table 4. Thermal Resistance θJA 170 Unit °C/W Maximum Power Dissipation The maximum safe power dissipation for the ADA4860-1 is limited by the associated rise in junction temperature (TJ) on the die. At approximately 150°C, which is the glass transition temperature, the plastic changes its properties. Even temporarily exceeding this temperature limit can change the stresses that the package exerts on the die, permanently shifting the parametric performance of the amplifiers. Exceeding a junction temperature of 150°C for an extended period can result in changes in silicon devices, potentially causing degradation or loss of functionality. MAXIMUM POWER DISSIPATION (W) 2.0 θJA is specified for the worst-case conditions, that is, θJA is specified for device soldered in circuit board for surface-mount packages. Package Type 6-lead SOT-23 ) PD = VSUPPLY VOLTAGE × I SUPPLY CURRENT – 1.5 1.0 0.5 0 –40 –30 –20 –10 05709-002 Parameter Supply Voltage Power Dissipation Common-Mode Input Voltage Differential Input Voltage Storage Temperature Range Operating Temperature Range Lead Temperature Junction Temperature 0 10 20 30 40 50 60 70 80 90 100 110 AMBIENT TEMPERATURE (°C) Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board ESD 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 this product 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. Rev. 0 | Page 5 of 20 ADA4860-1 TYPICAL PERFORMANCE CHARACTERISTICS RL = 150 Ω and CL = 4 pF, unless otherwise noted. G = +1, RF = 550Ω 1 –1 NORMALIZED GAIN (dB) 0 G = +2, RF = RG = 499Ω –2 G = –1, RF = RG = 499Ω –3 –4 G = +5, RF = 348Ω, RG = 86.6Ω –5 G = +10, RF = 348Ω, RG = 38.3Ω –6 0.1 1 10 100 VS = 5V VOUT = 0.2V p-p –1 G = +2, RF = RG = 499Ω –2 G = –1, RF = RG = 499Ω –3 –4 G = +5, RF = 348Ω, RG = 86.6Ω G = +10, RF = 348Ω, RG = 38.3Ω –6 0.1 1000 1 FREQUENCY (MHz) 2 VS = ±5V VOUT = 2V p-p 1 G = –1, RF = RG = 499Ω 0 G = +5, RF = 348Ω, RG = 86.6Ω –2 G = +2, RF = RG = 499Ω –3 G = +10, RF = 348Ω, RG = 38.3Ω –4 G = +1, RF = 550Ω –6 0.1 1 10 100 VS = 5V VOUT = 2V p-p 0 G = +5, RF = 348Ω, RG = 86.6Ω –1 G = +2, RF = RG = 499Ω –2 G = +10, RF = 348Ω, RG = 38.3Ω –3 G = +1, RF = 550Ω –4 –6 0.1 1000 1 FREQUENCY (MHz) 100 1000 Figure 8. Large Signal Frequency Response for Various Gains 7 G = +2 6.2 VOUT = 2V p-p RF = RG = 499Ω 6.1 6 CLOSED-LOOP GAIN (dB) 6.3 6.0 5.9 VS = +5V VS = ±5V 5.7 5.6 5 VOUT = 4V p-p 4 VOUT = 2V p-p 3 VOUT = 1V p-p 2 5.5 1 10 100 VS = ±5V G = +2 RF = RG = 499Ω 0 0.1 1000 1 05709-014 5.4 5.3 0.1 1 05709-003 CLOSED-LOOP GAIN (dB) 10 FREQUENCY (MHz) Figure 5. Large Signal Frequency Response for Various Gains 5.8 G = –1, RF = RG = 499Ω –5 05709-012 –5 1000 05709-013 –1 100 Figure 7. Small Signal Frequency Response for Various Gains NORMALIZED GAIN (dB) NORMALIZED GAIN (dB) 1 10 FREQUENCY (MHz) Figure 4. Small Signal Frequency Response for Various Gains 2 G = +1, RF = 550Ω 0 –5 05709-008 NORMALIZED GAIN (dB) 1 2 VS = ±5V VOUT = 0.2V p-p 05709-007 2 10 100 1000 FREQUENCY (MHz) FREQUENCY (MHz) Figure 9. Large Signal Frequency Response for Various Output Levels Figure 6. Large Signal 0.1 dB Flatness Rev. 0 | Page 6 of 20 ADA4860-1 6 6 5 RF = 604Ω 4 RF = 499Ω 3 RF = 402Ω 2 1 10 100 RF = 604Ω 5 RF = 499Ω 4 3 2 1 05709-009 1 0 0.1 RF = 301Ω RF = 402Ω RF = 301Ω CLOSED-LOOP GAIN (dB) CLOSED-LOOP GAIN (dB) 7 7 VS = ±5V G = +2 RG = RF VOUT = 0.2V p-p VS = ±5V G = +2 RG = RF VOUT = 2V p-p 0 0.1 1000 1 FREQUENCY (MHz) 2 G = +1, RF = 550Ω 1 0 –1 G = +2, RF = RG = 499Ω –2 –3 –4 1 10 100 VS = 5V VOUT = 0.2V p-p RL = 75Ω –1 G = +2, RF = RG = 499Ω –2 –3 –4 05709-005 –6 0.1 1000 1 1 NORMALIZED GAIN (dB) –1 G = +1, RF = 550Ω –2 –3 G = +2, RF = RG = 499Ω –4 10 1000 100 VS = 5V VOUT = 2V p-p RL = 75Ω 0 –1 G = +1, RF = 550Ω –2 –3 G = +2, RF = RG = 499Ω –4 –5 –6 0.1 1000 FREQUENCY (MHz) 05709-016 –5 05709-015 NORMALIZED GAIN (dB) 2 0 1 100 Figure 14. Small Signal Frequency Response for Various Gains VS = ±5V VOUT = 2V p-p RL = 75Ω –6 0.1 10 FREQUENCY (MHz) Figure 11. Small Signal Frequency Response for Various Gains 1 G = +1, RF = 550Ω 0 FREQUENCY (MHz) 2 1000 –5 05709-006 –5 –6 0.1 100 Figure 13. Large Signal Frequency Response vs. RF NORMALIZED GAIN (dB) NORMALIZED GAIN (dB) 1 VS = ±5V VOUT = 0.2V p-p RL = 75Ω 10 FREQUENCY (MHz) Figure 10. Small Signal Frequency Response vs. RF 2 05709-004 8 1 10 100 1000 FREQUENCY (MHz) Figure 15. Large Signal Frequency Response for Various Gains Figure 12. Large Signal Frequency Response for Various Gains Rev. 0 | Page 7 of 20 ADA4860-1 –40 –50 –60 VS = ±5V G = +2 RF = RG = 499Ω –50 –60 VOUT = 3V p-p, HD3 DISTORTION (dBc) DISTORTION (dBc) –40 VS = ±5V G = +1 RF = 550Ω –70 VOUT = 3V p-p, HD2 –80 VOUT = 2V p-p, HD2 –90 VOUT = 2V p-p, HD2 –70 VOUT = 3V p-p, HD2 –80 VOUT = 3V p-p, HD3 –90 VOUT = 2V p-p, HD3 1 10 –110 100 1 10 FREQUENCY (MHz) VS = 5V G = +1 RF = 550Ω –50 Figure 19. Harmonic Distortion vs. Frequency –40 VS = 5V G = +2 RF = RG = 499Ω VOUT = 2V p-p, HD2 –50 VOUT = 2V p-p, HD3 –70 VOUT = 1V p-p, HD2 VOUT = 1V p-p, HD3 1 10 VOUT = 1V p-p, HD2 –80 VOUT = 1V p-p, HD3 –90 –100 05709-018 –100 VOUT = 2V p-p, HD2 –70 –110 100 05709-019 –90 –110 VOUT = 2V p-p, HD3 –60 DISTORTION (dBc) DISTORTION (dBc) –60 –80 1 10 FREQUENCY (MHz) –40 DISTORTION (dBc) –60 VOUT = 1V p-p, HD2 VS = +5V –80 VOUT = 2V p-p, HD3 VS = ±5V –90 VOUT = 1V p-p, HD3 VS = +5V –110 1 10 VOUT = 2V p-p, HD2 VS = ±5V –70 VOUT = 2V p-p, HD3 VS = ±5V –80 VOUT = 1V p-p, HD3 VS = +5V –90 –100 05709-061 –100 VOUT = 1V p-p, HD2 VS = +5V –110 100 FREQUENCY (MHz) 05709-062 –70 G = +2 RF = RG = 499Ω RL = 100Ω –50 VOUT = 2V p-p, HD2 VS = ±5V –60 DISTORTION (dBc) Figure 20. Harmonic Distortion vs. Frequency G = +1 RF = 550Ω RL = 100Ω –50 100 FREQUENCY (MHz) Figure 17. Harmonic Distortion vs. Frequency –40 100 FREQUENCY (MHz) Figure 16. Harmonic Distortion vs. Frequency –40 05709-041 –110 VOUT = 2V p-p, HD3 –100 05709-017 –100 1 10 100 FREQUENCY (MHz) Figure 21. Harmonic Distortion vs. Frequency for Various Supplies Figure 18. Harmonic Distortion vs. Frequency for Various Supplies Rev. 0 | Page 8 of 20 ADA4860-1 200 2.7 200 2.7 VS = ±5V 0 2.5 –100 2.4 2.3 –200 2.6 VS = ±5V 0 2.5 –100 05709-033 G = +1 VOUT = 0.2V p-p RF = 550Ω TIME = 5ns/DIV 100 –200 2.4 G = +2 VOUT = 0.2V p-p RF = RG = 499Ω TIME = 5ns/DIV 200 200 CL = 9pF CL = 9pF CL = 6pF 0 CL = 6pF VS = ±5V G = +1 VOUT = 0.2V p-p RF = 550Ω TIME = 5ns/DIV 100 CL = 4pF 0 –100 –200 Figure 23. Small Signal Transient Response for Various Capacitor Loads Figure 26. Small Signal Transient Response for Various Capacitor Loads 2.7 2.7 CL = 9pF CL = 6pF CL = 6pF CL = 4pF 2.6 2.5 2.3 VS = 5V G = +1 VOUT = 0.2V p-p RF = 550Ω TIME = 5ns/DIV CL = 4pF 2.5 2.4 2.3 Figure 24. Small Signal Transient Response for Various Capacitor Loads VS = 5V G = +2 VOUT = 0.2V p-p RF = RG = 499Ω TIME = 5ns/DIV 05709-022 OUTPUT VOLTAGE (V) CL = 9pF 05709-035 OUTPUT VOLTAGE (V) 2.6 2.4 VS = ±5V G = +2 VOUT = 0.2V p-p RF = RG = 499Ω TIME = 5ns/DIV 05709-021 OUTPUT VOLTAGE (mV) 100 05709-034 OUTPUT VOLTAGE (mV) CL = 4pF –200 2.3 Figure 25. Small Signal Transient Response for Various Supplies Figure 22. Small Signal Transient Response for Various Supplies –100 OUTPUT VOLTAGE (V) +VS = 5V, –VS = 0V 2.6 05709-020 100 OUTPUT VOLTAGE (mV) ±VS = 5V VS = +5V OUTPUT VOLTAGE (V) +VS = 5V, –VS = 0V OUTPUT VOLTAGE (mV) ±VS = 5V VS = +5V Figure 27. Small Signal Transient Response for Various Capacitor Loads Rev. 0 | Page 9 of 20 ADA4860-1 0 2.5 –0.5 2.0 1.5 CL = 9pF 3.5 0.5 3.0 0 2.5 –0.5 2.0 1.5 CL = 6pF CL = 9pF OUTPUT VOLTAGE (V) –0.5 4.0 CL = 6pF VS = ±5V G = +2 VOUT = 2V p-p RF = RG = 499Ω TIME = 5ns/DIV CL = 9pF CL = 6pF 3.5 OUTPUT VOLTAGE (V) 3.0 2.5 2.0 VS = 5V G = +1 VOUT = 2V p-p RF = 550Ω TIME = 5ns/DIV CL = 4pF 3.0 2.5 2.0 1.5 05709-039 OUTPUT VOLTAGE (V) CL = 4pF Figure 32. Large Signal Transient Response for Various Capacitor Loads CL = 4pF 1.0 CL = 6pF 0 –1.5 3.5 1.5 0.5 –1.0 Figure 29. Large Signal Transient Response for Various Capacitor Loads 4.0 CL = 9pF 05709-024 VS = ±5V G = +1 VOUT = 2V p-p RF = 550Ω TIME = 5ns/DIV 05709-037 OUTPUT VOLTAGE (V) CL = 4pF –0.5 –1.5 1.0 1.0 0 –1.0 1.5 Figure 31. Large Signal Transient Response for Various Supplies 1.0 0.5 G = +2 VOUT = 2V p-p RF = RG = 499Ω TIME = 5ns/DIV –1.5 Figure 28. Large Signal Transient Response for Various Supplies 1.5 1.0 –1.0 1.0 VS = +5V 1.0 Figure 30. Large Signal Transient Response for Various Capacitor Loads VS = 5V G = +2 VOUT = 2V p-p RF = RG = 499Ω TIME = 5ns/DIV 05709-025 –1.5 OUTPUT VOLTAGE (V) ±VS = 5V 3.0 OUTPUT VOLTAGE (V) +VS = 5V, –VS = 0V 0.5 05709-036 OUTPUT VOLTAGE (V) ±VS = 5V 3.5 G = +1 VOUT = 2V p-p RF = 550Ω TIME = 5ns/DIV 4.0 VS = ±5V 1.0 –1.0 1.5 VS = +5V OUTPUT VOLTAGE (V) +VS = 5V, –VS = 0V 4.0 VS = ±5V 05709-023 1.5 Figure 33. Large Signal Transient Response for Various Capacitor Loads Rev. 0 | Page 10 of 20 ADA4860-1 2500 1600 VS = ±5V G = +1 RF = 550Ω VS = ±5V G = +2 RF = RG = 499Ω 1400 2000 SLEW RATE (V/µs) SLEW RATE (V/µs) 1200 POSITIVE SLEW RATE 1500 1000 NEGATIVE SLEW RATE POSITIVE SLEW RATE 1000 800 NEGATIVE SLEW RATE 600 400 500 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0 4.5 0 0.25 0.50 INPUT VOLTAGE (V p-p) 900 VS = 5V G = +1 RF = 550Ω 700 500 NEGATIVE SLEW RATE 400 NEGATIVE SLEW RATE 200 1.5 2.0 100 2.5 POSITIVE SLEW RATE 400 200 0 0.25 INPUT VOLTAGE (V p-p) 1.00 t = 0s 0.75 0.50 0.50 SETTLING TIME (%) 0.75 0.25 1V 0 –0.25 VS = ±5V G = +2 VOUT = 2V p-p RF = RG = 499Ω TIME = 5ns/DIV 1.00 1.25 VS = ±5V G = +2 VOUT = 2V p-p RF = RG = 499Ω TIME = 5ns/DIV 0.25 1V 0 –0.25 –0.50 –0.75 05709-027 SETTLING TIME (%) VIN –1.00 0.75 Figure 38. Slew Rate vs. Input Voltage 1.00 t = 0s 0.50 INPUT VOLTAGE (V p-p) Figure 35. Slew Rate vs. Input Voltage –0.75 2.25 500 300 –0.50 2.00 600 300 1.0 1.75 05709-029 SLEW RATE (V/µs) 600 05709-026 SLEW RATE (V/µs) POSITIVE SLEW RATE 0.5 1.50 VS = 5V G = +2 RF = RG = 499Ω 800 700 0 1.25 Figure 37. Slew Rate vs. Input Voltage 900 100 1.00 INPUT VOLTAGE (V p-p) Figure 34. Slew Rate vs. Input Voltage 800 0.75 –1.00 Figure 36. Settling Time Rising Edge VIN Figure 39. Settling Time Falling Edge Rev. 0 | Page 11 of 20 05709-030 0 05709-028 05709-043 0 200 ADA4860-1 30 110 20 15 10 5 100 1k 10k 100k 1M 10M 90 80 70 60 50 40 NONINVERTING INPUT 30 INVERTING INPUT 20 05709-032 INPUT CURRENT NOISE (pA/ Hz) 25 0 10 VS = ±5V, +5V 100 05709-031 INPUT VOLTAGE NOISE (nV/ Hz) VS = ±5V, +5V 10 0 10 100M 100 1k FREQUENCY (Hz) –20 –PSR –40 +PSR –50 –60 –70 0.1 1 10 100 –10 –30 –40 –50 –60 –70 0.1 1000 1 10 5.5 OUTPUT VOLTAGE 1 0 –1 –2 –3 –4 –5 200 300 400 500 600 700 800 900 4.5 4.0 3.5 OUTPUT VOLTAGE 3.0 2.5 2.0 1.5 1.0 0.5 05709-042 OUTPUT AND INPUT VOLTAGE (V) 3 VS = 5V G = +2 RF = RG = 499Ω f = 1MHz INPUT VOLTAGE × 2 5.0 05709-040 OUTPUT AND INPUT VOLTAGE (V) 4 100 1000 Figure 44. Common-Mode Rejection vs. Frequency VS = ±5V G = +2 RF = RG = 499Ω f = 1MHz INPUT VOLTAGE × 2 0 100 FREQUENCY (MHz) 6 –6 100M –20 Figure 41. Power Supply Rejection vs. Frequency 2 10M VS = ±5V VOUT = 200mV rms RF = 560Ω FREQUENCY (MHz) 5 1M 05709-055 COMMON-MODE REJECTION (dB) –10 05709-053 POWER SUPPLY REJECTION (dB) 0 VS = ±5V G = +2 –30 100k Figure 43. Input Current Noise vs. Frequency Figure 40. Input Voltage Noise vs. Frequency 0 10k FREQUENCY (Hz) 0 –0.5 1000 TIME (ns) 0 100 200 300 400 500 600 700 800 TIME (ns) Figure 45. Output Overdrive Recovery Figure 42. Output Overdrive Recovery Rev. 0 | Page 12 of 20 900 1000 ADA4860-1 VS = ±5V G = +2 100 40 0 30 20 –45 –90 1 0.1 1 10 VS = +5V –10 –30 05709-054 –180 1000 100 VS = ±5V 0 –20 –135 0.1 0.01 10 –40 –5 05709-058 10 INPUT VOS (mV) PHASE PHASE (Degrees) TRANSIMPEDANCE –4 –3 –2 –1 FREQUENCY (MHz) 0 1 2 3 4 5 VCM (V) Figure 49. Input VOS vs. Common-Mode Voltage Figure 46. Transimpedance and Phase vs. Frequency 7.0 6.5 5.5 VS = +5V 5.0 4.5 4.0 –40 –25 –10 5 20 35 50 65 80 95 110 VS = ±5V VS = +5V 2 0 –2 –4 05709-056 –6 –8 –10 –5 –4 –3 –2 –1 0 1 5.0 4.5 4 5 6 7 8 9 10 Figure 50. Supply Current vs. Supply Voltage 10 4 5.5 SUPPLY VOLTAGE (V) Figure 47. Supply Current at Various Supplies vs. Temperature 6 6.0 4.0 125 TEMPERATURE (°C) 8 6.5 05709-057 TOTAL SUPPLY CURRENT (mA) 6.0 05709-059 TOTAL SUPPLY CURRENT (mA) VS = ±5V INPUT BIAS CURRENT (µA) TRANSIMPEDANCE (kΩ) 1000 2 3 4 5 OUTPUT VOLTAGE (V) Figure 48. Inverting Input Bias Current vs. Output Voltage Rev. 0 | Page 13 of 20 11 12 ADA4860-1 APPLICATION INFORMATION Figure 51 and Figure 52 show the typical noninverting and inverting configurations and the recommended bypass capacitor values. +VS 0.1µF VIN – Table 5. Recommended Values and Frequency Performance1 Gain +1 −1 +2 +5 +10 1 RF (Ω) 550 499 499 348 348 RG (Ω) N/A 499 499 86.6 38.3 VOUT 0.1µF 10µF + –VS RF RG The feedback resistor has a direct impact on the closed-loop bandwidth and stability of the current feedback op amp circuit. Reducing the resistance below the recommended value can make the amplifier response peak and even become unstable. Increasing the size of the feedback resistor reduces the closedloop bandwidth. Table 5 provides a convenient reference for quickly determining the feedback and gain set resistor values and bandwidth for common gain configurations. −3 dB LS BW (MHz) 165 400 230 265 195 + ADA4860-1 FEEDBACK RESISTOR SELECTION −3 dB SS BW (MHz) 800 400 520 335 165 10µF + 05709-010 Attention must be paid to bypassing the power supply pins of the ADA4860-1. High quality capacitors with low equivalent series resistance (ESR), such as multilayer ceramic capacitors (MLCCs), should be used to minimize supply voltage ripple and power dissipation. Generally, a 10 μF tantalum capacitor located in close proximity to the ADA4860-1 is required to provide good decoupling for lower frequency signals. In addition, a 0.1 μF decoupling multilayer ceramic chip capacitor (MLCC) should be located as close to each of the power supply pins as is physically possible, no more than ⅛ inch away. The ground returns should terminate immediately into the ground plane. Locating the bypass capacitor return close to the load return minimizes ground loops and improves performance. Large Signal 0.1 dB Flatness 40 80 125 100 28 Conditions: VS = ±5 V, TA = 25°C, RL = 150 Ω. Rev. 0 | Page 14 of 20 Figure 51. Noninverting Gain RF +VS 10µF + 0.1µF VIN RG – ADA4860-1 + VOUT 0.1µF 10µF + –VS Figure 52. Inverting Gain 05709-011 POWER SUPPLY BYPASSING ADA4860-1 DRIVING CAPACITIVE LOADS POWER DOWN PIN If driving loads with a capacitive component is desired, the best frequency response is obtained by the addition of a small series resistance, as shown in Figure 53. Figure 54 shows the optimum value for RSERIES vs. capacitive load. The test was performed with a 50 MHz, 50% duty cycle pulse, with an amplitude of 200 mV p-p. The criteria for RSERIES selection was based on maintaining approximately 1 dB of peaking in small signal frequency response. It is worth noting that the frequency response of the circuit can be dominated by the passive roll-off of RSERIES and CL. The ADA4860-1 is equipped with a power-down function. The POWER DOWN pin allows the user to reduce the quiescent supply current when the amplifier is not being used. The power-down threshold levels are derived from the voltage applied to the −VS pin. When used in single-supply applications, this is especially useful with conventional logic levels. The amplifier is powered down when the voltage applied to the POWER DOWN pin is greater than (−VS + 0.5 V). The amplifier is enabled whenever the POWER DOWN pin is left open, or the voltage on the POWER DOWN pin is less than (−VS + 0.5 V). If the POWER DOWN pin is not used, it should be connected to the negative supply. ADA4860-1 VIN RSERIES RL VIDEO AMPLIFIER 05709-052 CL RF 750Ω With low differential gain and phase errors and wide 0.1 dB flatness, the ADA4860-1 is an ideal solution for consumer and professional video applications. Figure 55 shows a typical video driver set for a noninverting gain of +2, where RF = RG = 499 Ω. The video amplifier input is terminated into a shunt 75 Ω resistor. At the output, the amplifier has a series 75 Ω resistor for impedance matching to the video load. Figure 53. Driving Capacitive Loads 14 10 8 RF 6 +VS 10µF + 4 – 0 10 20 30 40 ADA4860-1 + 50 CAPACITIVE LOAD (pF) 0.1µF 75Ω CABLE VOUT 75Ω 10µF + 75Ω CABLE Figure 54. Recommended RSERIES vs. Capacitive Load 75Ω VIN 75Ω –VS 05709-038 0 0.1µF RG 2 05709-060 SERIES RESISTANCE (Ω) 12 Figure 55. Video Driver Schematic SINGLE-SUPPLY OPERATION Single-supply operation can present certain challenges for the designer. For a detailed explanation on op amp single-supply operation, see Application Note AN-581. Rev. 0 | Page 15 of 20 ADA4860-1 When using the ADA4860-1, a variety of circuit conditions and parasitics can affect peaking, gain flatness, and −3 dB bandwidth. This section discusses how the ADA4860-1 small signal responses can be dramatically altered with basic circuit changes and added stray capacitances, see the Layout and Circuit Board Parasitics section for more information. Particularly with low closed-loop gains, the feedback resistor (Rf) effects peaking and gain flatness. However, with gain = +1, −3 dB bandwidth varies slightly, while gain = +2 has a much larger variation. For gain = +1, Figure 56 shows the effect that various feedback resistors have on frequency response. In Figure 56, peaking is wide ranging yet −3 dB bandwidths vary by only 6%. In this case, the user must pick what is desired: more peaking or flatter bandwidth. Figure 57 shows gain = +2 bandwidth and peaking variations vs. RF and RL. Bandwidth delta vs. RL increase was approximately 17%. As RF is reduced from 560 Ω to 301 Ω, the −3 dB bandwidth changes 49%, with excessive compromises in peaking, see Figure 57. For more gain = +2 bandwidth variations vs. RF, see Figure 10 and Figure 13. DASH LINE IS PLANE CLEAR OUT AREA (EXCEPT SUPPLY PINS) DURING PC LAYOUT. + VS = ±5V G = +1 1 VOUT = 0.1V p-p RL = 100Ω RF ADDED C J EXAMPLE In Figure 59, a slight −3 dB bandwidth delta of approximately +10% can be seen going from a small-to-large case size. The increase in bandwidth with the larger 1206 case size is caused by an increase in parasitic capacitance across the chip resistor. 0 RF = 910Ω RF = 1.5kΩ –2 –3 –4 05709-044 1 10 100 1000 10000 RF = 301Ω, RL = 100Ω 0 –1 RF = 560Ω, RL = 100Ω RF = 560Ω, RL = 1kΩ –3 –4 05709-045 1 10 100 1206 RESISTOR SIZE –4 VS = ±5V G = +2 VOUT = 0.1V p-p –5 RG = RF = 560Ω RL = 100Ω 1 0402 RESISTOR SIZE 10 100 1000 Figure 59. Small Signal Frequency Response vs. Resistor Size 2 –5 –3 FREQUENCY (MHz) FREQUENCY (MHz) –2 –2 –6 Figure 56. Small Signal Frequency Response vs. RF VS = ±5V G = +2 1 VOUT = 0.1V p-p RG = RF –1 05709-046 NORMALIZED GAIN (dB) RF = 680Ω –5 NORMALIZED GAIN (dB) ADDED C LOAD EXAMPLE RG Figure 58. Noninverting Gain Setup for Illustration of Parasitic Effects, 50 Ω System, RL = 100 Ω –1 –6 50Ω – RF = 560Ω 0 –6 49.9Ω 49.9Ω 1 2 NORMALIZED GAIN (dB) The impact of resistor case sizes was observed using the circuit drawn in Figure 58. The types and sizes chosen were 0402 case sized thin film and 1206 thick film. All other measurement conditions were kept constant except for the case size and resistor composition. 05709-049 OPTIMIZING FLATNESS AND BANDWIDTH 1000 FREQUENCY (MHz) Figure 57. Small Signal Frequency Response vs. RF vs. RL Rev. 0 | Page 16 of 20 ADA4860-1 LAYOUT AND CIRCUIT BOARD PARASITICS 1 G = +2, RF = 560Ω, CJ = 0.4pF EXTRA 3 VS = ±5V G = +2 2 V OUT = 0.1V p-p RF = RG = 560Ω 1 RL = 1kΩ, CL = 0pF –3 RL = 100Ω, CL = 0pF 1 10 100 1000 Figure 61. Small Signal Frequency Response vs. Output Capacitive Load For more information on high speed board layout, go to: www.analog.com and www.analog.com/library/analogDialogue/archives/3909/layout.html. G = +2, RF = 560Ω, CJ = 0pF –3 –4 05709-047 NORMALIZED GAIN (dB) –2 FREQUENCY (MHz) G = –2, RF = 402Ω, CJ = 0pF 100 –1 –6 –2 10 0 –5 G = –2, RF = 402Ω, CJ = 0.4pF EXTRA –5 VS = ±5V VOUT = 0.1V p-p RL = 100Ω –6 1 RL = 100Ω, CL = 5.6pF EXTRA –4 0 –1 RL = 1kΩ, CL = 5.6pF EXTRA 05709-048 To illustrate the affects of parasitic capacitance, a small capacitor of 0.4 pF from the amplifiers summing junction (inverting input) to ground was intentionally added. This was done on two boards with equal and opposite gains of +2 and −2. Figure 60 reveals the effects of parasitic capacitance at the summing junction for both noninverting and inverting gain circuits. With gain = +2, the additional 0.4 pF of added capacitance created an extra 43% −3 dB bandwidth extension, plus some extra peaking. For gain = −2, a 5% increase in −3 dB bandwidth was created with an extra 0.4 pF on summing junction. In a second test, 5.6 pF of capacitance was added directly at the output of the gain = +2 amplifier. Figure 61 shows the results. Extra output capacitive loading on the ADA4860-1 also causes bandwidth extensions, as seen in Figure 61. The effect on the gain = +2 circuit is more pronounced with lighter resistive loading (1 kΩ). For pulse response behavior with added output capacitances, see Figure 23, Figure 24, Figure 26, Figure 27, Figure 29, Figure 30, Figure 32, and Figure 33. NORMALIZED GAIN (dB) Careful attention to printed circuit board (PCB) layout prevents associated board parasitics from becoming problematic and affecting gain flatness and −3 dB bandwidth. In the printed circuit environment, parasitics around the summing junction (inverting input) or output pins can alter pulse and frequency response. Parasitic capacitance can be unintentionally created on a PC board via two parallel metal planes with a small vertical separation (in FR4). To avoid parasitic problems near the summing junction, signal line connections between the feedback and gain resistors should be kept as short as possible to minimize the inductance and stray capacitance. For similar reasons, termination and load resistors should be located as close as possible to the respective inputs. Removing the ground plane on all layers from the area near and under the input and output pins reduces stray capacitance. 1000 FREQUENCY (MHz) Figure 60. Small Signal Frequency Response vs. Added Summing Junction Capacitance Rev. 0 | Page 17 of 20 ADA4860-1 OUTLINE DIMENSIONS 2.90 BSC 6 5 4 1 2 3 2.80 BSC 1.60 BSC PIN 1 INDICATOR 0.95 BSC 1.30 1.15 0.90 1.90 BSC 1.45 MAX 0.15 MAX 0.50 0.30 0.22 0.08 SEATING PLANE 10° 4° 0° 0.60 0.45 0.30 COMPLIANT TO JEDEC STANDARDS MO-178-AB Figure 62. 6-Lead Plastic Surface-Mount Package [SOT-23] (RJ-6) Dimensions shown in millimeters ORDERING GUIDE Model ADA4860-1YRJZ-RL 1 ADA4860-1YRJZ-RL71 ADA4860-1YRJZ-R21 1 Temperature Range –40°C to +105°C –40°C to +105°C –40°C to +105°C Package Description 6-Lead SOT-23 6-Lead SOT-23 6-Lead SOT-23 Z = Pb-free part. Rev. 0 | Page 18 of 20 Ordering Quantity 10,000 3,000 250 Package Option RJ-6 RJ-6 RJ-6 Branding HKB HKB HKB ADA4860-1 NOTES Rev. 0 | Page 19 of 20 ADA4860-1 NOTES ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05709-0-4/06(0) Rev. 0 | Page 20 of 20