AD8027

Low Distortion, High Speed Rail-to-Rail Input/Output Amplifiers AD8027/AD8028 FEATURES High speed 190 MHz, –3 dB bandwidth (G = +1) 100 V/μs slew rate Low distortion 120 dBc @ 1 MHz SFDR 80 dBc @ 5 MHz SFDR Selectable input crossover threshold Low noise 4.3 nV/√Hz 1.6 pA/√Hz Low offset voltage: 900 μV max Low power: 6.5 mA/amplifier supply current Power-down mode No phase reversal: VIN > |VS| + 200 mV Wide supply range: 2.7 V to 12 V Small packaging: SOIC-8, SOT-23-6, MSOP-10 AD8027 SOIC-8 (R) NC 1 –IN 2 +IN 3 –VS 4 8 7 6 5 CONNECTION DIAGRAMS AD8027 SOT-23-6 (RT) DISABLE/SELECT +VS VOUT NC +IN 3 4 VOUT 1 –VS 2 6 +VS DISABLE/SELECT + – 5 NC = NO CONNECT –IN AD8028 SOIC-8 (R) VOUTA 1 –IN A 2 +IN A 3 –VS 4 – + – + 8 7 6 5 AD8028 MSOP-10 (RM) +VS VOUTB –IN B +IN B VOUTA 1 –IN A 2 +IN A 3 –VS 4 DISABLE/SELECT A 5 03327-B-001 10 +VS – + – + 9 8 7 6 VOUTB –IN B +IN B DISABLE/SELECT B Figure 1. Connection Diagrams (Top View) APPLICATIONS Filters ADC drivers Level shifting Buffering Professional video Low voltage instrumentation With their wide supply voltage range (2.7 V to 12 V) and wide bandwidth (190 MHz), the AD8027/AD8028 amplifiers are designed to work in a variety of applications where speed and performance are needed on low supply voltages. The high performance of the AD8027/AD8028 is achieved with a quiescent current of only 6.5 mA/amplifier typical. The AD8027/AD8028 have a shutdown mode that is controlled via the SELECT pin. The AD8027/AD8028 are available in SOIC-8, MSOP-10, and SOT-23-6 packages. They are rated to work over the industrial temperature range of –40°C to +125°C. –20 G = +1 FREQUENCY = 100kHz RL = 1kΩ GENERAL DESCRIPTION The AD8027/AD80281 are high speed amplifiers with rail-torail input and output that operate on low supply voltages and are optimized for high performance and wide dynamic signal range. The AD8027/AD8028 have low noise (4.3 nV/√Hz, 1.6 pA/√Hz) and low distortion (120 dBc at 1 MHz). In applications that use a fraction of, or the entire input dynamic range and require low distortion, the AD8027/AD8028 are ideal choices. Many rail-to-rail input amplifiers have an input stage that switches from one differential pair to another as the input signal crosses a threshold voltage, which causes distortion. The AD8027/AD8028 have a unique feature that allows the user to select the input crossover threshold voltage through the SELECT pin. This feature controls the voltage at which the complementary transistor input pairs switch. The AD8027/ AD8028 also have intrinsically low crossover distortion. –40 –60 VS = +3V SFDR (dB) VS = +5V VS = ±5V –80 –100 –120 –140 0 1 2 3 4 5 6 7 OUTPUT VOLTAGE (V p-p) 8 9 10 03327-A-063 Figure 2. SFDR vs. Output Amplitude 1 Protected by U.S. patent numbers 6,486,737B1; 6,518,842B1 Rev. C 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 © 2005 Analog Devices, Inc. All rights reserved. AD8027/AD8028 TABLE OF CONTENTS Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 6 Maximum Power Dissipation ..................................................... 6 ESD Caution.................................................................................. 6 Typical Performance Characteristics ............................................. 8 Theory of Operation ...................................................................... 17 Input Stage................................................................................... 17 Crossover Selection .................................................................... 17 Output Stage................................................................................ 18 DC Errors .................................................................................... 18 Wideband Operation ..................................................................... 19 Circuit Considerations .............................................................. 19 Applications..................................................................................... 21 Using the SELECT Pin............................................................... 21 Driving a 16-Bit ADC................................................................ 21 Band-Pass Filter.......................................................................... 22 Design Tools and Technical Support ....................................... 22 Outline Dimensions ....................................................................... 23 Ordering Guide .......................................................................... 24 REVISION HISTORY 3/05—Rev. B to Rev. C Updated Format..................................................................Universal Change to Figure 1 ........................................................................... 1 10/03—Rev. A to Rev. B Changes to Figure 1...........................................................................1 8/03—Rev. 0 to Rev. A Addition of AD8028........................................................... Universal Changes to GENERAL DESCRIPTION.........................................1 Changes to Figures 1, 3, 4, 8, 13, 15, 17 ......................... 1, 6, 7, 8, 9 Changes to Figures 58, 60........................................................ 18, 20 Changes to SPECIFICATIONS........................................................3 Updated OUTLINE DIMENSIONS .............................................22 Updated ORDERING GUIDE.......................................................23 3/03—Revision 0: Initial Version Rev. C | Page 2 of 24 AD8027/AD8028 SPECIFICATIONS VS = ±5 V at TA = 25°C, RL = 1 kΩ to midsupply, G = 1, unless otherwise noted. Table 1. Parameter DYNAMIC PERFORMANCE –3 dB Bandwidth Bandwidth for 0.1 dB Flatness Slew Rate Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Spurious-Free Dynamic Range (SFDR) Input Voltage Noise Input Current Noise Differential Gain Error Differential Phase Error Crosstalk, Output to Output DC PERFORMANCE Input Offset Voltage Input Offset Voltage Drift Input Bias Current 1 Conditions G = 1, VO = 0.2 V p-p G = 1, VO = 2 V p-p G = 2, VO = 0.2 V p-p G = +1, VO = 2 V step/G = −1, VO = 2 V step G = 2, VO = 2 V step fC = 1 MHz, VO = 2 V p-p, RF = 24.9 Ω fC = 5 MHz, VO = 2 V p-p, RF = 24.9 Ω f = 100 kHz f = 100 kHz NTSC, G = 2, RL = 150 Ω NTSC, G = 2, RL = 150 Ω G = 1, RL = 100 Ω, VOUT = 2 V p-p, VS = ±5 V @ 1 MHz SELECT = three-state or open, PNP active SELECT = high NPN active TMIN to TMAX VCM = 0 V, NPN active TMIN to TMAX VCM = 0 V, PNP active TMIN to TMAX VO = ±2.5 V 100 Min 138 20 Typ 190 32 16 90/100 35 120 80 4.3 1.6 0.1 0.2 −93 Max Unit MHz MHz MHz V/μs ns dBc dBc nV/√Hz pA/√Hz % Degrees dB Input Offset Current Open-Loop Gain INPUT CHARACTERISTICS Input Impedance Input Capacitance Input Common-Mode Voltage Range Common-Mode Rejection Ratio SELECT PIN Crossover Low, Selection Input Voltage Crossover High, Selection Input Voltage Disable Input Voltage Disable Switching Speed Enable Switching Speed OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rising/Falling Edge) Output Voltage Swing Short-Circuit Output Off Isolation Capacitive Load Drive POWER SUPPLY Operating Range Quiescent Current/Amplifier Quiescent Current (Disabled) Power Supply Rejection Ratio 200 240 1.50 4 4 −8 −8 ±0.1 110 6 2 −5.2 to +5.2 110 −3.3 to +5 −3.9 to −3.3 −5 to −3.9 980 45 40/45 800 900 6 −11 ±0.9 μV μV μV/°C μA μA μA μA μA dB MΩ pF V dB V V V ns ns ns VCM = ±2.5 V Three-state < ±20 μA 90 50% of input to