Low Distortion Differential ADC Driver AD8138-EP FEATURES PIN CONFIGURATION Adjustable output common-mode voltage Low harmonic distortion −94 dBc SFDR @ 5 MHz −85 dBc SFDR @ 20 MHz −3 dB bandwidth of 320 MHz, G = +1 Fast settling to 0.01% of 16 ns Fast overdrive recovery of 4 ns Low input voltage noise of 5 nV/√Hz Low power 90 mW on 5 V –IN 1 8 +IN VOCM 2 7 NC V+ 3 6 V– +OUT 4 5 –OUT NC = NO CONNECT 08997-001 AD8138-EP Figure 1. TYPICAL APPLICATION CIRCUIT ENHANCED PRODUCT FEATURES 5V 5V 499Ω VIN 499Ω + VOCM 499Ω AIN AVDD DVDD DIGITAL OUTPUTS ADC AD8138-EP AIN – AVSS VREF 08997-002 Supports defense and aerospace applications (AQEC) Extended temperature range −55ºC to +105°C Controlled manufacturing baseline One assembly/test site One fabrication site Enhanced product change notification Qualification data available on request 499Ω Figure 2. APPLICATIONS ADC drivers Single-ended-to-differential converters IF and baseband gain blocks Differential buffers Line drivers GENERAL DESCRIPTION The AD8138-EP is a major advancement over op amps for differential signal processing. The AD8138-EP can be used as a single-ended-to-differential amplifier or as a differential-todifferential amplifier. The AD8138-EP is as easy to use as an op amp and greatly simplifies differential signal amplification and driving. Manufactured on Analog Devices, Inc., proprietary XFCB bipolar process, the AD8138-EP has a −3 dB bandwidth of 320 MHz and delivers a differential signal with the lowest harmonic distortion available in a differential amplifier. The AD8138-EP has a unique internal feedback feature that provides balanced output gain and phase matching, suppressing even order harmonics. The internal feedback circuit also minimizes any gain error that would be associated with the mismatches in the external gain setting resistors. The AD8138-EP’s differential output helps balance the input to the differential ADCs, maximizing the performance of the ADC. The AD8138-EP eliminates the need for a transformer with high performance ADCs, preserving the low frequency and dc information. The common-mode level of the differential output is adjustable by a voltage on the VOCM pin, easily level-shifting the input signals for driving single-supply ADCs. Fast overload recovery preserves sampling accuracy. The AD8138-EP distortion performance makes it an ideal ADC driver for communication systems, with distortion performance good enough to drive state-of-the-art 10-bit to 16-bit converters at high frequencies. The AD8138-EP’s high bandwidth and IP3 also make it appropriate for use as a gain block in IF and baseband signal chains. The AD8138-EP offset and dynamic performance make it well suited for a wide variety of signal processing and data acquisition applications. The AD8138-EP is available in the MSOP package for operation over −55°C to +105°C temperatures. Full details about this enhanced product are available in the AD8138 data sheet, which should be consulted in conjunction with this data sheet. 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 ©2010 Analog Devices, Inc. All rights reserved. AD8138-EP TABLE OF CONTENTS Features .............................................................................................. 1 VOCM to ±OUT Specifications ......................................................6 Enhanced Product Features ............................................................ 1 Absolute Maximum Ratings ............................................................7 Applications ....................................................................................... 1 Thermal Resistance .......................................................................7 General Description ......................................................................... 1 Maximum Power Dissipation ......................................................7 Pin Configuration ............................................................................. 1 ESD Caution...................................................................................7 Typical Application Circuit ............................................................. 1 Maximum Output Voltage Swing................................................8 Revision History ............................................................................... 2 Pin Configuration and Function Descriptions..............................9 Specifications..................................................................................... 3 Outline Dimensions ....................................................................... 10 ±DIN to ±OUT Specifications...................................................... 3 Ordering Guide .......................................................................... 10 VOCM to ±OUT Specifications ..................................................... 4 ±DIN to ±OUT Specifications...................................................... 5 REVISION HISTORY 4/10—Revision 0: Initial Version Rev. 0 | Page 2 of 12 AD8138-EP SPECIFICATIONS ±DIN TO ±OUT SPECIFICATIONS At 25°C, VS = ±5 V, VOCM = 0 V, G = +1, RL, dm = 500 Ω, unless otherwise noted. All specifications refer to single-ended input and differential outputs, unless otherwise noted. Table 1. Parameter DYNAMIC PERFORMANCE −3 dB Small Signal Bandwidth Bandwidth for 0.1 dB Flatness Large Signal Bandwidth Slew Rate Settling Time Overdrive Recovery Time NOISE/HARMONIC PERFORMANCE Second Harmonic Third Harmonic IMD IP3 Voltage Noise (RTI) Input Current Noise INPUT CHARACTERISTICS Offset Voltage Conditions Min Typ VOUT = 0.5 V p-p, CF = 0 pF TMIN to TMAX 1 VOUT = 0.5 V p-p, CF = 1 pF VOUT = 0.5 V p-p, CF = 0 pF VOUT = 2 V p-p, CF = 0 pF VOUT = 2 V p-p, CF = 0 pF 0.01%, VOUT = 2 V p-p, CF = 1 pF VIN = 5 V to 0 V step, G = +2 290 256 320 VOUT = 2 V p-p, 5 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 20 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 70 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 5 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 20 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 70 MHz, RL, dm = 800 Ω 20 MHz 20 MHz f = 100 kHz to 40 MHz f = 100 kHz to 40 MHz VOS, dm = VOUT, dm/2; VDIN+ = VDIN− = VOCM = 0 V TMIN to TMAX1 Input Bias Current Input Resistance Input Capacitance Input Common-Mode Voltage CMRR OUTPUT CHARACTERISTICS Output Voltage Swing 2 Output Balance Error 1 2 TMIN to TMAX variation Differential Common mode ΔVOUT, dm/ΔVIN, cm; ΔVIN, cm = ±1 V, TMIN to TMAX1 Maximum ΔVOUT; single-ended output ΔVOUT, cm/ΔVOUT, dm; ΔVOUT, dm = 1 V Specified to ±6 sigma over the −55°C to +105°C operating temperature range. Output swing capabilities vary over operating temperature. See Figure 4 for more information. Rev. 0 | Page 3 of 12 −2.5 −4.8 Max Unit 225 30 265 1150 16 4 MHz MHz MHz MHz MHz V/μs ns ns −94 −87 −62 −114 −85 −57 −77 37 5 2 dBc dBc dBc dBc dBc dBc dBc dBm nV/√Hz pA/√Hz ±1 3.5 −0.01 6 3 1 −4.7 to +3.4 −77 7.75 −66 +2.5 +4.8 7 −70 −69 mV mV μA μA/°C MΩ MΩ pF V dB dB V p-p dB AD8138-EP VOCM TO ±OUT SPECIFICATIONS At 25°C, VS = ±5 V, VOCM = 0 V, G = +1, RL, dm = 500 Ω, unless otherwise noted. All specifications refer to single-ended input and differential outputs, unless otherwise noted. Table 2. Parameter DYNAMIC PERFORMANCE −3 dB Bandwidth Slew Rate INPUT VOLTAGE NOISE (RTI) DC PERFORMANCE Input Voltage Range Input Resistance Input Offset Voltage Input Bias Current VOCM CMRR Gain POWER SUPPLY Operating Range Quiescent Current Power Supply Rejection Ratio OPERATING TEMPERATURE RANGE 1 Conditions Min f = 0.1 MHz to 100 MHz VOS, cm = VOUT, cm; VDIN+ = VDIN– = VOCM = 0 V TMIN to TMAX 1 ΔVOUT, dm/ΔVOCM; ΔVOCM = ±1 V ΔVOUT, cm/ΔVOCM; ΔVOCM = ±1 V, TMIN to TMAX1 TMIN to TMAX1 ΔVOUT, dm/ΔVS; ΔVS = ±1 V, TMIN to TMAX1 −3.5 −10.2 0.9955 ±1.4 18 13.2 Rev. 0 | Page 4 of 12 Max Unit 250 330 17 MHz V/μs nV/√Hz ±3.8 200 ±1 V kΩ mV mV μA dB V/V +3.5 +10.2 0.5 −75 1 1.0045 20 ±5.5 23 −90 −55 Specified to ±6 sigma over the −55°C to +105°C operating temperature range. Typ −70 +105 V mA mA dB °C AD8138-EP ±DIN TO ±OUT SPECIFICATIONS At 25°C, VS = 5 V, VOCM = 2.5 V, G = +1, RL, dm = 500 Ω, unless otherwise noted. All specifications refer to single-ended input and differential output, unless otherwise noted. Table 3. Parameter DYNAMIC PERFORMANCE −3 dB Small Signal Bandwidth Bandwidth for 0.1 dB Flatness Large Signal Bandwidth Slew Rate Settling Time Overdrive Recovery Time NOISE/HARMONIC PERFORMANCE Second Harmonic Third Harmonic IMD IP3 Voltage Noise (RTI) Input Current Noise INPUT CHARACTERISTICS Offset Voltage Conditions Min Typ VOUT = 0.5 V p-p, CF = 0 pF TMIN to TMAX 1 VOUT = 0.5 V p-p, CF = 1 pF VOUT = 0.5 V p-p, CF = 0 pF VOUT = 2 V p-p, CF = 0 pF VOUT = 2 V p-p, CF = 0 pF 0.01%, VOUT = 2 V p-p, CF = 1 pF VIN = 2.5 V to 0 V step, G = +2 280 242 310 VOUT = 2 V p-p, 5 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 20 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 70 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 5 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 20 MHz, RL, dm = 800 Ω VOUT = 2 V p-p, 70 MHz, RL, dm = 800 Ω 20 MHz 20 MHz f = 100 kHz to 40 MHz f = 100 kHz to 40 MHz VOS, dm = VOUT, dm/2; VDIN+ = VDIN– = VOCM = 0 V TMIN to TMAX1 Input Bias Current Input Resistance Input Capacitance Input Common-Mode Voltage CMRR OUTPUT CHARACTERISTICS Output Voltage Swing 2 Output Balance Error 1 2 TMIN to TMAX variation Differential Common mode ΔVOUT, dm/ΔVIN, cm; ΔVIN, cm = 1 V TMIN to TMAX1 Maximum ∆VOUT; single-ended output ΔVOUT, cm/ΔVOUT, dm; ΔVOUT, dm = 1 V Specified to ±6 sigma over the −55°C to +105°C operating temperature range. Output swing capabilities vary over operating temperature. See Figure 5 for more information. Rev. 0 | Page 5 of 12 −2.5 −5.1 Max Unit 225 29 265 950 16 4 MHz MHz MHz MHz MHz V/μs ns ns −90 −79 −60 −100 −82 −53 −74 35 5 2 dBc dBc dBc dBc dBc dBc dBc dBm nV/√Hz pA/√Hz ±1 3.5 −0.01 6 3 1 −0.3 to +3.2 −77 2.9 −65 +2.5 +5.1 7 −70 −69.5 mV mV μA μA/°C MΩ MΩ pF V dB dB V p-p dB AD8138-EP VOCM TO ±OUT SPECIFICATIONS At 25°C, VS = 5 V, VOCM = 2.5 V, G = +1, RL, dm = 500 Ω, unless otherwise noted. All specifications refer to single-ended input and differential output, unless otherwise noted. Table 4. Parameter DYNAMIC PERFORMANCE −3 dB Bandwidth Slew Rate INPUT VOLTAGE NOISE (RTI) DC PERFORMANCE Input Voltage Range Input Resistance Input Offset Voltage Input Bias Current VOCM CMRR Gain POWER SUPPLY Operating Range Quiescent Current Power Supply Rejection Ratio Conditions Min f = 0.1 MHz to 100 MHz VOS, cm = VOUT, cm; VDIN+ = VDIN– = VOCM = 0 V TMIN to TMAX 1 ΔVOUT, dm/ΔVOCM; ΔVOCM = 2.5 V ± 1 V ΔVOUT, cm/ΔVOCM; ΔVOCM = 2.5 V ± 1 V, TMIN to TMAX1 TMIN to TMAX1 ΔVOUT, dm/ΔVS; ΔVS = ± 1 V TMIN to TMAX1 OPERATING TEMPERATURE RANGE 1 −5 −9.7 0.9968 2.7 15 10.6 Rev. 0 | Page 6 of 12 Max Unit 220 250 17 MHz V/μs nV/√Hz 1.0 to 3.8 100 ±1 V kΩ mV mV μA dB V/V +5 +9.7 0.5 −70 1 1.0032 20 11 21 −90 −55 Specified to ±6 sigma over the −55°C to +105°C operating temperature range. Typ −70 −57 +105 V mA mA dB dB °C AD8138-EP ABSOLUTE MAXIMUM RATINGS Figure 3 shows the maximum safe power dissipation vs. the ambient temperature for the 8-lead MSOP (θJA = 145°C/W) package on a JEDEC standard 4-layer board. θJA values are approximations. 1.75 Table 6. 1.50 0.75 0.50 95 105 85 65 75 45 55 0 AMBIENT TEMPERATURE (°C) Figure 3. Maximum Power Dissipation vs. Ambient Temperature ESD CAUTION Rev. 0 | Page 7 of 12 08997-003 0.25 25 The maximum safe power dissipation in the AD8138-EP package 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 AD8138-EP. Exceeding a junction temperature of 150°C for an extended period can result in changes in the silicon devices, potentially causing failure. 1.00 35 MAXIMUM POWER DISSIPATION 1.25 5 Unit °C/W 15 θJA 145 –55 Package Type 8-Lead MSOP/4-Layer MAXIMUM POWER DISSIPATION (W) θJA is specified for the worst-case conditions, that is, θJA is specified for the device soldered in a circuit board in still air. –5 THERMAL RESISTANCE Airflow reduces θJA. In addition, more metal directly in contact with the package leads from metal traces, through holes, ground, and power planes reduces the θJA. –15 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. The power dissipated in the package (PD) is the sum of the quiescent power dissipation and the power dissipated in the package due to the load drive for all outputs. The quiescent power is the voltage between the supply pins (VS) times the quiescent current (IS). The load current consists of the differential and common-mode currents flowing to the load, as well as currents flowing through the external feedback networks and internal common-mode feedback loop. The internal resistor tap used in the common-mode feedback loop places a negligible differential load on the output. RMS voltages and currents should be considered when dealing with ac signals. –25 Rating ±5.5 V ±VS See Figure 4 and Figure 5 550 mW −55°C to +105°C −65°C to +150°C 300°C 150°C –35 Parameter Supply Voltage VOCM Output Voltage Swing Internal Power Dissipation Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec) Junction Temperature –45 Table 5. AD8138-EP RL = 6.8kΩ 7 RL = 2kΩ 6 RL = 1kΩ 5 3 RL = 300Ω 2.6 RL = 200Ω 2.2 RL = 150Ω 1.8 VS = 5V VOUT MAX = 2.9V p-p 1.4 25 35 45 55 RL = 100Ω 65 75 85 95 105 AMBIENT TEMPERATURE (°C) Figure 5. Differential Output Voltage Swing vs. Ambient Temperature, VS = 5 V 4 RL = 500Ω VS = ±5V VOUT MAX = 7.75V p-p 3 25 115 08997-005 8 35 45 55 65 75 85 95 105 AMBIENT TEMPERATURE (°C) 115 08997-004 DIFFERENTIAL OUTPUT VOLTAGE SWING (V p-p) The maximum output voltage swing must be considered in order for the AD8138-EP to remain current density compliant over the extended temperature range. The maximum output swing is dependent on the load resistance and operating temperatures. Figure 4 shows the maximum output swing over operating temperatures for various loads at ±5 V operation. Figure 5 shows the maximum output swing over operating temperatures for various loads at VS = 5 V operation. DIFFERENTIAL OUTPUT VOLTAGE SWING (V p-p) MAXIMUM OUTPUT VOLTAGE SWING The following equation can be used to determine the maximum output voltage swing for VS = 5 V: Output = (24.36 × ln(RL) − 82.34) × e ( −0.028 × TA ) Figure 4. Differential Output Voltage Swing vs. Ambient Temperature, VS = ±5 V The following equation can be used to determine the maximum output voltage swing for VS = ±5 V: Output = (38.21 × ln(RL) − 169.26) × e ( −0.0293 × TA ) where: Output is the maximum output voltage swing that cannot exceed 2.9 V p-p. RL is the load resistance (Ω). TA is the ambient temperature (°C). where: Output is the maximum output voltage swing that cannot exceed 7.75 V p-p. RL is the load resistance (Ω). TA is the ambient temperature (°C). Rev. 0 | Page 8 of 12 AD8138-EP PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 8 +IN VOCM 2 7 NC V+ 3 6 V– +OUT 4 5 –OUT NC = NO CONNECT 08997-001 AD8138-EP –IN 1 Figure 6. Pin Configuration Table 7. Pin Function Descriptions Pin No. 1 2 Mnemonic −IN VOCM 3 4 5 6 7 8 V+ +OUT −OUT V− NC +IN Description Negative Input Summing Node. Voltage applied to this pin sets the common-mode output voltage with a ratio of 1:1. For example, 1 V dc on VOCM sets the dc bias level on +OUT and −OUT to 1 V. Positive Supply Voltage. Positive Output. Note that the voltage at −DIN is inverted at +OUT. Negative Output. Note that the voltage at +DIN is inverted at –OUT. Negative Supply Voltage. No Connect. Positive Input Summing Node. Rev. 0 | Page 9 of 12 AD8138-EP OUTLINE DIMENSIONS 3.20 3.00 2.80 8 3.20 3.00 2.80 1 5.15 4.90 4.65 5 4 PIN 1 IDENTIFIER 0.65 BSC 0.95 0.85 0.75 15° MAX 1.10 MAX 0.40 0.25 6° 0° 0.23 0.09 0.80 0.55 0.40 COMPLIANT TO JEDEC STANDARDS MO-187-AA 100709-B 0.15 0.05 COPLANARITY 0.10 Figure 7. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters ORDERING GUIDE Model 1 AD8138SRMZ-EP-R7 1 Temperature Range −55°C to +105°C Package Description 8-Lead MSOP, 7" Tape and Reel Z = RoHS Compliant Part. Rev. 0 | Page 10 of 12 Package Option RM-8 Branding H27 AD8138-EP NOTES Rev. 0 | Page 11 of 12 AD8138-EP NOTES ©2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08997-0-4/10(0) Rev. 0 | Page 12 of 12