High Gain Bandwidth Product Precision Fast FET ™ Op Amp AD8067 FEATURES • FET input amplifier: 0.6 pA input bias current • Stable for gains ≥8 • High speed • 54 MHz, –3 dB bandwidth (G = +10) • 640 V/µs slew rate • Low noise • 6.6 nV/√Hz • 0.6 fA/√Hz • Low offset voltage (1.0 mV max) • Wide supply voltage range: 5 V to 24 V • No phase reversal • Low input capacitance • Single-supply and rail-to-rail output • Excellent distortion specs: SFDR 95 dBc @ 1 MHz • High common-mode rejection ratio: –106 dB • Low power: 6.5 mA typical supply current • Low cost • Small packaging: SOT-23-5 APPLICATIONS CONNECTION DIAGRAM SOT-23-5 (RT-5) VOUT 1 5 +VS –VS 2 +IN 3 4 –IN Figure 1. Connection Diagram (Top View) The FET input bias current (5 pA max) and low voltage noise (6.6 nV/√Hz) also contribute to making it appropriate for precision applications. With a wide supply voltage range (5 V to 24 V) and rail-to-rail output, the AD8067 is well suited to a variety of applications that require wide dynamic range and low distortion. The AD8067 amplifier consumes only 6.5 mA of supply current, while capable of delivering 30 mA of load current and driving capacitive loads of 100 pF. The AD8067 amplifier is available in a SOT-23-5 package and is rated to operate over the industrial temperature range, –40°C to +85°C. • Photodiode preamplifier • Precision high gain amplifier • High gain, high bandwidth composite amplifier 28 26 G = +20 24 GENERAL DESCRIPTION The AD8067 is designed to work in applications that require high speed and low input bias current, such as fast photodiode preamplifiers. As required by photodiode applications, the laser trimmed AD8067 has excellent dc voltage offset (1.0 mV max) and drift (15 µV/°C max). GAIN – dB 22 The AD8067 Fast FET amp is a voltage feedback amplifier with FET inputs offering wide bandwidth (54 MHz @ G = +10) and high slew rate (640 V/µs). The AD8067 is fabricated in a proprietary, dielectrically isolated eXtra Fast Complementary Bipolar process (XFCB) that enables high speed, low power, and high performance FET input amplifiers. 20 18 G = +10 G = +8 16 14 12 10 8 0.1 1 10 FREQUENCY – MHz 100 Figure 2. Small Signal Frequency Response 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 companies. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.326.8703 © 2002 Analog Devices, Inc. All rights reserved. AD8067 TABLE OF CONTENTS AD8067–Specifications for ±5 V...........................................................4 Input Protection ................................................................................18 AD8067–Specifications for +5 V...........................................................5 Capacitive Load Drive ......................................................................18 AD8067–Specifications for ±12 V.........................................................6 Layout, Grounding, and Bypassing Considerations .....................18 Absolute Maximum Ratings ..................................................................7 Applications............................................................................................20 Maximum Power Dissipation............................................................7 Wideband Photodiode Preamp.......................................................20 Typical Performance Characteristics ....................................................8 Using the AD8067 at Gains of Less Than 8 ...................................21 Test Circuits............................................................................................13 Single-Supply Operation ..................................................................22 Theory of Operation .............................................................................15 High Gain, High Bandwidth Composite Amplifier......................22 Basic Frequency Response...............................................................15 Outline Dimensions ..............................................................................24 Resistor Selection for Wideband Operation..................................16 Ordering Guide .................................................................................24 Input and Output Overload Behavior............................................17 TABLES Table 1. Recommended Values of RG and RF .....................................15 Table 3. Ordering Guide........................................................................24 Table 2. RMS Noise Contributions of Photodiode Preamp.............20 REVISION HISTORY Revision 0: Initial Version Rev. 0 | Page 2 of 24 AD8067 FIGURES Figure 1. Connection Diagram (Top View)..........................................1 Figure 32. Output Saturation Voltage vs. Temperature .................... 12 Figure 2. Small Signal Frequency Response .........................................1 Figure 33. Open-Loop Gain vs. Load Current for Various Supplies.......................................................................................... 12 Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board ...............................................................................7 Figure 34. Standard Test Circuit.......................................................... 13 Figure 4. Small Signal Frequency Response for Various Gains .........8 Figure 35. Open-Loop Gain Test Circuit ........................................... 13 Figure 5. Small Signal Frequency Response for Various Supplies.....8 Figure 36. Test Circuit for Capacitive Load....................................... 13 Figure 6. Large Signal Frequency Response for Various Supplies.....8 Figure 37. CMRR Test Circuit ............................................................. 14 Figure 7. 0.1 dB Flatness Frequency Response ...................................8 Figure 38. Positive PSRR Test Circuit................................................. 14 Figure 8. Small Signal Frequency Response for Various CLOAD .........8 Figure 39. Output Impedance Test Circuit ........................................ 14 Figure 9. Frequency Response for Various Output Amplitudes ........8 Figure 40. Noninverting Gain Configuration ................................... 15 Figure 10. Small Signal Frequency Response for Various RF .............9 Figure 41. Open-Loop Frequency Response .................................... 15 Figure 11. Distortion vs. Frequency for Various Loads ......................9 Figure 42. Inverting Gain Configuration........................................... 15 Figure 12. Distortion vs. Frequency for Various Amplitudes.............9 Figure 43. Input and Board Capacitances.......................................... 16 Figure 13. Open-Loop Gain and Phase ................................................9 Figure 44. Op Amp DC Error Sources .............................................. 17 Figure 14. Distortion vs. Frequency for Various Supplies ..................9 Figure 45. Simplified Input Schematic ............................................. 17 Figure 15. Distortion vs. Output Amplitude for Various Loads ........9 Figure 46 Current Limiting Resistor .................................................. 18 Figure 16. Small Signal Transient Response 5 V Supply...................10 Figure 47. Guard-Ring Configurations .............................................. 18 Figure 17. Output Overdrive Recovery...............................................10 Figure 48. Guard-Ring Layout SOT-23-5 .......................................... 18 Figure 18. Long-Term Settling Time ...................................................10 Figure 49. Wideband Photodiode Preamp......................................... 20 Figure 19. Small Signal Transient Response ± 5 V Supply ...............10 Figure 50. Photodiode Voltage Noise Contributions ....................... 20 Figure 20. Large Signal Transient Response.......................................10 Figure 51. Photodiode Preamplifier ................................................... 21 Figure 21. 0.1% Short-Term Settling Time........................................10 Figure 52. Photodiode Preamplifier Frequency Response .............. 21 Figure 22. Input Bias Current vs. Temperature..................................11 Figure 53. Photodiode Preamplifier Pulse Response ....................... 21 Figure 23. Input Offset Voltage Histogram ........................................11 Figure 54. Gain of Less than 2 Schematic .......................................... 21 Figure 24. Voltage Noise........................................................................11 Figure 55. Gain of 2 Pulse Response .................................................. 22 Figure 25. Input Bias Current vs. Common-Mode Voltage..............11 Figure 56. Single-Supply Operation Schematic ................................ 22 Figure 26. Input Offset Voltage vs. Common-Mode Voltage ...........11 Figure 57. AD8067/AD8009 Composite ........................................... 23 Figure 27. CMRR vs. Frequency ..........................................................11 Figure 58. Gain Bandwidth Response ................................................ 23 Figure 28. Output Impedance vs. Frequency .....................................12 Figure 59. Large Signal Response........................................................ 23 Figure 29. Output Saturation Voltage vs. Output Load Current......12 Figure 60. Small Signal Response........................................................ 23 Figure 30. PSRR vs. Frequency.............................................................12 Figure 61. 5-Lead Plastic Surface Mount Package ........................... 24 Figure 31. Quiescent Current vs. Temperature for Various Supply Voltages..............................................................................12 Rev. 0 | Page 3 of 24 AD8067 AD8067–SPECIFICATIONS FOR ±5 V VS = ±5 V (@ TA = +25°C, G = +10, RF = RL =1 kΩ, Unless Otherwise Noted.) Parameter Min Typ 39 54 MHz VO = 2 V p-p 54 MHz Bandwidth for 0.1 dB Flatness VO = 0.2 V p-p 8 MHz Output Overdrive Recovery Time (Pos/Neg) VI = ±0.6 V 115/190 ns Slew Rate VO = 5 V Step 640 V/µs Settling Time to 0.1% VO = 5 V Step 27 ns fC = 1 MHz, 2 V p-p fC = 1 MHz, 8 V p-p fC = 5 MHz, 2 V p-p 95 84 82 72 6.6 0.6 0.2 dBc dBc dBc dBc nV/√Hz fA/√Hz mV –3 dB Bandwidth DYNAMIC PERFORMANCE NOISE/DISTORTION PERFORMANCE Spurious Free Dynamic Range (SFDR) Input Voltage Noise Input Current Noise Input Offset Voltage Conditions VO = 0.2 V p-p 500 fC = 1 MHz, 2 V p-p, RL = 150 Ω f = 10 kHz f = 10 kHz Input Offset Voltage Drift DC PERFORMANCE Input Bias Current Input Offset Current INPUT CHARACTERISTICS OUTPUT CHARACTERISTICS POWER SUPPLY TMIN to TMAX TMIN to TMAX VO = ±3 V Open-Loop Gain Common-Mode Input Impedance Differential Input Impedance Input Common-Mode Voltage Range Common-Mode Rejection Ratio (CMRR) VCM = –1 V to +1 V RL = 1 kΩ Output Voltage Swing RL = 150 Ω Output Current Short Circuit Current Capacitive Load Drive Operating Range Quiescent Current 103 1 0.6 25 0.2 1 119 1000||1.5 1000||2.5 1 –4.67 to +4.72 30 105 120 30% over shoot 5 6.5 –90 Rev. 0 | Page 4 of 24 1.0 15 5 –5.0 2.0 –85 –106 –4.86 to +4.83 –4.92 to +4.92 SFDR > 60 dBc, f = 1 MHz Power Supply Rejection Ratio (PSRR) Max –109 24 6.8 Unit µV/°C pA pA pA pA dB GΩ||pF GΩ||pF V dB V V mA mA pF V mA dB AD8067 AD8067–SPECIFICATIONS FOR +5 V VS = +5 V (@ TA = +25°C, G = +10, RL =RF = 1 kΩ, Unless Otherwise Noted.) Parameter Conditions VO = 0.2 V p-p Min Typ 36 54 MHz VO = 2 V p-p 54 MHz Bandwidth for 0.1 dB Flatness VO = 0.2 V p-p 8 MHz Output Overdrive Recovery Time (Pos/Neg) VI = +0.6 V 150/200 ns Slew Rate VO = 3 V Step 490 V/µs VO = 2 V Step 25 ns fC = 1 MHz, 2 V p-p fC = 1 MHz, 4 V p-p fC = 5 MHz, 2 V p-p fC = 1 MHz, 2 V p-p, RL = 150 Ω f = 10 kHz f = 10 kHz 86 74 60 72 6.6 0.6 0.2 dBc dBc dBc dBc nV/√Hz fA/√Hz mV –3 dB Bandwidth DYNAMIC PERFORMANCE Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Spurious Free Dynamic Range (SFDR) Input Voltage Noise Input Current Noise Input Offset Voltage 390 Input Offset Voltage Drift DC PERFORMANCE Input Bias Current Input Offset Current Open-Loop Gain INPUT CHARACTERISTICS Common-Mode Input Impedance Differential Input Impedance Input Common-Mode Voltage Range Common-Mode Rejection Ratio (CMRR) Output Voltage Swing OUTPUT CHARACTERISTICS POWER SUPPLY Output Current Short Circuit Current Capacitive Load Drive Operating Range Quiescent Current 1 0.5 25 0.1 TMIN to TMAX TMIN to TMAX VO = 0.5 V to 4.5 V VCM = 0.5 Vto 1.5 V RL = 1 kΩ 100 Max 1.0 15 5 1 Unit µV/°C pA pA pA pA 117 dB 1000||2.3 1000||2.5 GΩ||pF GΩ||pF V dB V 0 –81 –98 0.07 to 4.89 0.03 to 4.94 2.0 RL =150 Ω 0.08 to 4.83 V SFDR > 60 dBc, f = 1 MHz 22 95 120 mA mA pF V mA 30% over shoot 5 6.4 Power Supply Rejection Ratio (PSRR) –87 Rev. 0 | Page 5 of 24 –103 24 6.7 dB AD8067 AD8067–SPECIFICATIONS FOR ±12 V VS = ±12 V (@ TA = +25°C, G = +10, RL = RF = 1 kΩ, Unless Otherwise Noted.) Parameter Min Typ 39 54 MHz VO = 2 V p-p 53 MHz Bandwidth for 0.1 dB Flatness VO = 0.2 V p-p 8 MHz Output Overdrive Recovery Time (Pos/Neg) VI = ±1.5 V 75/180 ns Slew Rate VO = 5 V Step 640 V/µs Settling Time to 0.1% VO = 5 V Step 27 ns fC = 1 MHz, 2 V p-p fC = 1 MHz, 20 V p-p fC = 5 MHz, 2 V p-p fC = 1 MHz, 2V p-p, RL = 150 Ω f = 10 kHz f = 10 kHz 92 84 74 72 6.6 0.6 0.2 dBc dBc dBc dBc nV/√Hz fA/√Hz mV –3 dB Bandwidth DYNAMIC PERFORMANCE NOISE/DISTORTION PERFORMANCE Spurious Free Dynamic Range (SFDR) Input Voltage Noise Input Current Noise Input Offset Voltage Conditions VO = 0.2 V p-p 500 Input Offset Voltage Drift DC PERFORMANCE Input Bias Current Input Offset Current Open-Loop Gain INPUT CHARACTERISTICS Common-Mode Input Impedance Differential Input Impedance Input Common-Mode Voltage Range Common-Mode Rejection Ratio (CMRR) Output Voltage Swing OUTPUT CHARACTERISTICS POWER SUPPLY Output Current Short Circuit Current Capacitive Load Drive Operating Range Quiescent Current 1 1.0 25 0.2 TMIN to TMAX TMIN to TMAX VO = ±10 V VCM = –1 V to +1 V RL = 1 kΩ 107 15 5 1 30% over shoot µV/°C pA pA pA pA dB 1000||1.5 1000||2.5 GΩ||pF GΩ||pF V dB V 5 6.6 –86 Unit 119 –11.31 to +11.73 26 125 120 SFDR > 60 dBc, f = 1 MHz Rev. 0 | Page 6 of 24 1.0 –12.0 9.0 –89 –108 –11.70 to +11.70 –11.85 to +11.84 RL = 500 Ω Power Supply Rejection Ratio (PSRR) Max –97 24 7.0 V mA mA pF V mA dB AD8067 ABSOLUTE MAXIMUM RATINGS Rating 26.4 V See Figure 3 VEE – 0.5 V to VCC + 0.5 V 1.8 V –65°C to +125°C –40°C to +85°C 300°C If the RMS signal levels are indeterminate, then consider the worst case, when VOUT = VS/4 for RL to midsupply: PD = (VS × I S ) + 150°C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and 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. Maximum Power Dissipation The associated raise in junction temperature (TJ) on the die limits the maximum safe power dissipation in the AD8067 package. At approximately 150°C, which is the glass transition temperature, the plastic will change its properties. Even temporarily exceeding this temperature limit may change the stresses that the package exerts on the die, permanently shifting the parametric performance of the AD8067. Exceeding a junction temperature of 175°C for an extended period of time can result in changes in the silicon devices, potentially causing failure. 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. The quiescent power is the voltage between the supply pins (VS) times the quiescent current (IS). Assuming the load (RL) is referenced to midsupply, the total drive power is VS/2 × IOUT, some of which is dissipated in the package and some in the load (VOUT × IOUT). The difference between the total drive power and the load power is the drive power dissipated in the package. RMS output voltages should be considered. VOUT 2 – RL RL Airflow will increase heat dissipation effectively, reducing θJA. In addition, more metal directly in contact with the package leads from metal traces, through holes, ground, and power planes will reduce the θJA. Figure 3 shows the maximum safe power dissipation in the package versus ambient temperature for the SOT-23-5 (180°C/W) package on a JEDEC standard 4-layer board. θJA values are approximations. It should be noted that for every 10°C rise in temperature, IB approximately doubles (See Figure 22). 2.0 1.5 1.0 SOT-23-5 0.5 0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE – °C PD = Quiescent Power + (Total Drive Power – Load Power ) V V PD = (VS × I S ) + S × OUT RL 2 (VS / 4 )2 In single-supply operation with RL referenced to VS–, worst case is VOUT = VS/2. MAXIMUM POWER DISSAPATION – W Parameter Supply Voltage Power Dissipation Common-Mode Input Voltage Differential Input Voltage Storage Temperature Operating Temperature Range Lead Temperature Range (Soldering 10 sec) Junction Temperature Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board If RL is referenced to VS– as in single-supply operation, then the total drive power is VS × IOUT. Rev. 0 | Page 7 of 24 AD8067 TYPICAL PERFORMANCE CHARACTERISTICS Default Conditions VS = ±5 V (@ TA = +25°C, G = +10, RL = RF = 1 kΩ, Unless Otherwise Noted.) 20.7 28 26 24 20.5 22 20.4 G = +10 20 G = +8 18 G = +6 16 VOUT = 0.2V p-p 20.6 GAIN – dB GAIN – dB VOUT = 200mV p-p G = +20 VOUT = 0.7V p-p VOUT = 1.4V p-p 20.3 20.2 20.1 14 20.0 12 19.9 10 8 19.8 1 10 FREQUENCY – MHz 100 1 24 VOUT = 200mV p-p VS = +5V 21 22 VS = ±5V GAIN – dB GAIN – dB VS = ±12V 18 20 CL = 100pF RSNUB = 24.9Ω 19 18 17 17 16 16 CL = 5pF 15 15 14 1 10 FREQUENCY – MHz 1 100 10 FREQUENCY – MHz 100 Figure 8. Small Signal Frequency Response for Various CLOAD Figure 5. Small Signal Frequency Response for Various Supplies 22 22 VOUT = 2V p-p VS = +5V 21 21 VS = ±5V VOUT = 4V p-p GAIN – dB VS = ±12V 19 VOUT = 0.2V p-p, 2V p-p 20 20 GAIN – dB CL = 25pF 21 19 18 19 18 17 17 16 16 15 15 14 CL = 100pF VOUT = 200mV p-p 23 20 14 100 Figure 7. 0.1 dB Flatness Frequency Response Figure 4. Small Signal Frequency Response for Various Gains 22 10 FREQUENCY – MHz 14 1 10 FREQUENCY – MHz 100 1 10 FREQUENCY – MHz 100 Figure 9. Frequency Response for Various Output Amplitudes Figure 6. Large Signal Frequency Response for Various Supplies Rev. 0 | Page 8 of 24 AD8067 VOUT = 200mV p-p RF = 2kΩ 21 RF = 1kΩ 90 120 80 90 70 60 PHASE 60 RF = 499Ω 19 GAIN – dB GAIN – dB 20 18 17 30 50 0 40 –30 GAIN 30 –60 PHASE – Degrees 22 20 –90 10 –120 0 –150 16 15 14 1 10 FREQUENCY – MHz –10 0.01 100 0.1 Figure 10. Small Signal Frequency Response for Various RF –40 HD2 RLOAD = 150Ω –70 HD3 RLOAD = 150Ω –80 HD2 RLOAD = 1kΩ –90 –100 –110 DISTORTION – dBc DISTORTION – dBc –60 VOUT = 2V p-p HD3 RLOAD = 1kΩ –120 G = +10 VS = ±5V –140 0.1 1 –70 –90 –100 HD2 VS = ±5V –110 HD3 VS = ±12V 10 FREQUENCY – MHz HD3 VS = ±5V –130 –140 0.1 100 Figure 11. Distortion vs. Frequency for Various Loads –20 HD2 VS = ±12V –80 –120 –130 1 –30 VS = ±12V G = +10 DISTORTION – dBc –50 –60 HD2 VOUT = 20V p-p HD3 VOUT = 2V p-p HD2 VOUT = 2V p-p HD3 VOUT = 20V p-p –120 HD2 RLOAD = 150Ω –60 –70 HD3 RLOAD = 150Ω –80 –90 HD2 RLOAD = 1kΩ –100 –110 HD3 RLOAD = 1kΩ –120 –140 0.1 1 10 FREQUENCY – MHz 100 VS = ±12V f = 1MHz G = +10 –40 –100 10 FREQUENCY – MHz Figure 14. Distortion vs. Frequency for Various Supplies –40 DISTORTION – dBc G = +10 VOUT = 2V p-p –50 –60 –80 –180 1k 100 Figure 13. Open-Loop Gain and Phase –40 –50 1 10 FREQUENCY – MHz –130 100 Figure 12. Distortion vs. Frequency for Various Amplitudes 0 2 4 6 8 10 12 14 16 18 OUTPUT AMPLITUDE – V p-p 20 22 24 Figure 15. Distortion vs. Output Amplitude for Various Loads Rev. 0 | Page 9 of 24 AD8067 G = +10 VIN = 20mV p-p G = +10 VIN = 20mV p-p CL = 100pF CL = 0pF 1.5V 50mV/DIV 50mV/DIV 25ns/DIV Figure 16. Small Signal Transient Response 5 V Supply 10VIN Figure 19. Small Signal Transient Response ± 5 V Supply G = +10 VOUT VS = ±12V VIN = 2V p-p G = +10 200ns/DIV 2V/DIV 25ns/DIV 5V/DIV Figure 17. Output Overdrive Recovery 50ns/DIV Figure 20. Large Signal Transient Response VOUT (1V/DIV) G = +10 VIN (100mV/DIV) VOUT – 10VIN (5mV/DIV) +0.1% +0.1% VIN (100mV/DIV) VOUT – 10VIN (5mV/DIV) –0.1% –0.1% t=0 5µs/DIV Figure 18. Long-Term Settling Time 5ns/DIV Figure 21. 0.1% Short-Term Settling Time Rev. 0 | Page 10 of 24 AD8067 14 10 8 INPUT BIAS CURRENT – pA INPUT BIAS CURRENT – pA 12 10 8 6 VS = ±12V 4 VS = ±12V VS = ±5V VS = +5V 6 4 2 0 –2 –4 –6 2 –8 VS = ±5V 0 25 35 45 55 65 TEMPERATURE – °C 75 –10 –14 –12 –10 –8 –6 –4 –2 0 2 4 6 8 COMMON-MODE VOLTAGE – V 85 Figure 25. Input Bias Current vs. Common-Mode Voltage Figure 22. Input Bias Current vs. Temperature 1800 5 N = 12255 SD = 0.203 MEAN = –0.033 4 INPUT OFFSET VOLTAGE – mV 1600 1400 COUNT 1200 1000 800 600 400 200 0 10 12 14 VS = ±12V 3 VS = ±5V 2 1 VS = +5V 0 –1 –2 –6 –4 –1 0 INPUT OFFSET VOLTAGE – mV –5 –14 –12 –10 –8 –6 –4 –2 0 2 4 6 8 COMMON-MODE VOLTAGE – V 1 10 12 14 Figure 26. Input Offset Voltage vs. Common-Mode Voltage Figure 23. Input Offset Voltage Histogram –40 1000 –50 100 CMRR – dB NOISE – nV/ Hz –60 10 –70 –80 –90 –100 –110 1 1 10 100 1k 10k 100k FREQUENCY – Hz 1M 10M –120 0.1 100M 1 10 FREQUENCY – MHz Figure 27. CMRR vs. Frequency Figure 24. Voltage Noise Rev. 0 | Page 11 of 24 100 AD8067 6.7 100 G = +10 VS = ±12V QUIESCENT CURRENT – mA 6.6 OUTPUT IMPEDANCE – Ω 10 1 0.1 6.3 6.2 6.0 –40 0.001 0.01 0.1 1 10 FREQUENCY – MHz 100 200 OUTPUT SATURATION VOLTAGE – mV 0.25 VCC – VOH 0.20 VOL – VEE 0.15 0.10 0.05 0 5 10 15 20 25 ILOAD – mA 30 80 35 (VCC – VOH), (VOL – VEE), VS = ±12V 140 120 100 (VCC – VOH), (VOL – VEE), VS = ±5V 80 VCC – VOH, VS = +5V 60 40 VOL – VEE, VS = +5V 20 0 –40 40 130 –20 120 OPEN-LOOP GAIN – dB –10 –PSRR –10 –50 –60 +PSRR –20 0 20 40 TEMPERATURE – °C 60 80 Figure 32. Output Saturation Voltage vs. Temperature 140 VS = ±12V 110 100 90 VS = ±5V 80 VS = +5V 70 –80 60 –90 –100 0.01 60 160 0 –70 20 40 TEMPERATURE – °C RL = 1kΩ 180 Figure 29. Output Saturation Voltage vs. Output Load Current –30 0 Figure 31. Quiescent Current vs. Temperature for Various Supply Voltages 0.30 0 –20 1000 Figure 28. Output Impedance vs. Frequency OUTPUT SATURATION VOLTAGE – V VS = +5V 6.4 6.1 0.01 PSRR – dB VS = ±5V 6.5 50 0.1 1 FREQUENCY – MHz 10 100 Figure 30. PSRR vs. Frequency 0 5 10 15 20 25 ILOAD – mA 30 35 40 Figure 33. Open-Loop Gain vs. Load Current for Various Supplies Rev. 0 | Page 12 of 24 AD8067 TEST CIRCUITS +VCC 10µF + 0.1µF 1kΩ 110Ω 5 4 VIN AD8067 49.9Ω 3 VOUT 1 RL = 1kΩ 2 0.1µF 10µF + AV = 10 –VEE Figure 34. Standard Test Circuit +VCC 10µF + 0.1µF 110Ω V– 1kΩ 5 4 AD8067 100Ω 3 VOUT 1 1kΩ 2 0.1µF 10µF AOL = VOUT V– + –VEE Figure 35. Open-Loop Gain Test Circuit +VCC 10µF + 0.1µF 110Ω 1kΩ 4 VIN 49.9Ω 5 AD8067 3 2 RSNUB 0.1µF CLOAD 10µF + AV = 10 VOUT 1 –VEE Figure 36. Test Circuit for Capacitive Load Rev. 0 | Page 13 of 24 1kΩ AD8067 +VCC 10µF + 0.1µF 110Ω 1kΩ VIN 5 4 AD8067 110Ω 3 2 1kΩ VOUT 1 1kΩ 0.1µF 10µF + –VEE Figure 37. CMRR Test Circuit VIN 110Ω 1kΩ +VCC 5 4 AD8067 3 VOUT 1 1kΩ 2 0.1µF 100Ω 10µF + –VEE Figure 38. Positive PSRR Test Circuit +VCC 10µF + 0.1µF 110Ω 1kΩ 4 100Ω 5 AD8067 3 2 VOUT 1 NETWORK ANALYZER 0.1µF 10µF + –VEE Figure 39. Output Impedance Test Circuit Rev. 0 | Page 14 of 24 AD8067 THEORY OF OPERATION The combination of low noise, dc precision, and high bandwidth makes the AD8067 uniquely suited for wideband, very high input impedance, high gain buffer applications. It will also prove useful in wideband transimpedance applications, such as a photodiode interface, that require very low input currents and dc precision. Basic Frequency Response The AD8067’s typical open-loop response (see Figure 41) shows a phase margin of 60° at a gain of +10. Typical configurations for noninverting and inverting voltage gain applications are shown in Figure 40 and Figure 42. The closed-loop frequency response of a basic noninverting gain configuration can be approximated using the equation: Closed Loop – 3 dB Frequency = (GBP ) × RG (RF + RG ) DC Gain = RF /RG + 1 GBP is the gain bandwidth product of the amplifier. Typical GBP for the AD8067 is 300 MHz. See Table 1 for recommended values of RG and RF. Noninverting Configuration Noise Gain = +VS RS RX 0.1µF 90 120 80 90 60 30 50 0 40 –30 GAIN 30 –60 20 –90 10 –120 0 –150 –10 0.01 0.1 1 10 FREQUENCY – MHz Gain 10 20 50 100 RG (Ω) 110 49.9 20 10 0.1µF BW (MHz) 54 15 6 3 +VS 0.1µF RX + 10µF + AD8067 RLOAD 10µF + 0.1µF + VOUT – RS –VS RG RF (kΩ) 1 1 1 1 – RLOAD –180 Table 1. Recommended Values of RG and RF RF +1 RG + 10µF – 1k The bandwidth formula only holds true when the phase margin of the application approaches 90°, which it will in high gain configurations. The bandwidth of the AD8067 used in a G = +10 buffer is 54 MHz, considerably faster than the 30 MHz predicted by the closed loop –3 dB frequency equation. This extended bandwidth is due to the phase margin being at 60° instead of 90°. Gains lower than +10 will show an increased amount of peaking, as shown in Figure 4. For gains lower than +7, use the AD8065, a unity gain stable JFET input op amp with a unity gain bandwidth of 145 MHz, or refer to the Applications section for using the AD8067 in a gain of 2 configuration. + SIGNAL SOURCE 100 Figure 41. Open-Loop Frequency Response AD8067 VI 60 PHASE PHASE – Degrees 70 GAIN – dB The AD8067 is a low noise, wideband, voltage feedback operational amplifier that combines a precision JFET input stage with Analog Devices’ dielectrically isolated eXtra Fast Complementary Bipolar (XFCB) process BJTs. Operating supply voltages range from 5 V to 24 V. The amplifier features a patented rail-to-rail output stage capable of driving within 0.25 V of either power supply while sourcing or sinking 30 mA. The JFET input, composed of N-channel devices, has a common-mode input range that includes the negative supply rail and extends to 3 V below the positive supply. In addition, the potential for phase reversal behavior has been eliminated for all input voltages within the power supplies. RG 10µF + + VOUT – –VS RF VI RF FOR BEST PERFORMANCE, SET RS + RX = RG || RF SIGNAL SOURCE FOR BEST PERFORMANCE, SET RX = (RS + RG) || RF Figure 40. Noninverting Gain Configuration Figure 42. Inverting Gain Configuration Rev. 0 | Page 15 of 24 AD8067 For inverting voltage gain applications, the source impedance of the input signal must be considered because that will set the application’s noise gain as well as the apparent closed-loop gain. The basic frequency equation for inverting applications is below. Closed Loop – 3 dB Frequency = (GBP) × DC Gain = – + CPAR VI CM CD CM – – RG + R S RF + R G + R S + VOUT – RF SIGNAL SOURCE CPAR RG RF RG + R S GBP is the gain bandwidth product of the amplifier, and RS is the signal source resistance. Inverting Configuration Noise Gain = + RS R F + RG + R S RG + R S It is important that the noise gain for inverting applications be kept above 6 for stability reasons. If the signal source driving the inverter is another amplifier, take care that the driving amplifier shows low output impedance through the frequency span of the expected closed-loop bandwidth of the AD8067. Figure 43. Input and Board Capacitances There will be a pole in the feedback loop response formed by the source impedance seen by the amplifier’s negative input (RG RF) and the sum of the amplifier’s differential input capacitance, common-mode input capacitance, and any board parasitic capacitance. This will decrease the loop phase margin and can cause stability problems, i.e., unacceptable peaking and ringing in the response. To avoid this problem it is recommended that the resistance at the AD8067’s negative input be kept below 200 Ω for all wideband voltage gain applications. Matching the impedances at the inputs of the AD8067 is also recommended for wideband voltage gain applications. This will minimize nonlinear common-mode capacitive effects that can significantly degrade settling time and distortion performance. Resistor Selection for Wideband Operation Voltage feedback amplifiers can use a wide range of resistor values to set their gain. Proper design of the application’s feedback network requires consideration of the following issues: • Poles formed by the amplifier’s input capacitances with the resistances seen at the amplifier’s input terminals • Effects of mismatched source impedances • Resistor value impact on the application’s output voltage noise • Amplifier loading effects The AD8067 has common-mode input capacitances (CM) of 1.5 pF and a differential input capacitance (CD) of 2.5 pF. This is illustrated in Figure 43. The source impedance driving the positive input of a noninverting buffer will form a pole primarily with the amplifier’s common-mode input capacitance as well as any parasitic capacitance due to the board layout (CPAR). This will limit the obtainable bandwidth. For G = +10 buffers, this bandwidth limit will become apparent for source impedances >1 kΩ. The AD8067 has a low input voltage noise of 6.6 nV/√Hz. Source resistances greater than 500 Ω at either input terminal will notably increase the apparent Referred to Input (RTI) voltage noise of the application. The amplifier must supply output current to its feedback network, as well as to the identified load. For instance, the load resistance presented to the amplifier in Figure 40 is RLOAD (RF + RG). For an RLOAD of 100 Ω, RF of 1 kΩ, and RG of 100 Ω, the amplifier will be driving a total load resistance of about 92 Ω. This becomes more of an issue as RF decreases. The AD8067 is rated to provide 30 mA of low distortion output current. Heavy output drive requirements also increase the part’s power dissipation and should be taken into account. Rev. 0 | Page 16 of 24 AD8067 DC ERROR CALCULATIONS Input and Output Overload Behavior Figure 44 illustrates the primary dc errors associated with a voltage feedback amplifier. For both inverting and noninverting configurations: R + RF Output Voltage Error due to VOS = VOS G RG R + RG Output Voltage Error due to I B = I B + × R S F RG – I B – × RF Total error is the sum of the two. DC common-mode and power supply effects can be added by modeling the total VOS with the expression: VOS (tot) = VOS (nom) + ∆VS ∆VCM + PSR CMR VOS (nom) is the offset voltage specified at nominal conditions (1 mV max). ∆VS is the change in power supply voltage from nominal conditions. PSR is power supply rejection (90 dB minimum). ∆VCM is the change in common-mode voltage from nominal test conditions. CMR is common-mode rejection (85 dB minimum for the AD8067). A simplified schematic of the AD8067 input stage is shown in Figure 45. This shows the cascoded N-channel JFET input pair, the ESD and other protection diodes, and the auxiliary NPN input stage that eliminates phase inversion behavior. When the common-mode input voltage to the amplifier is driven to within approximately 3 V of the positive power supply, the input JFET’s bias current will turn off, and the bias of the NPN pair will turn on, taking over control of the amplifier. The NPN differential pair now sets the amplifier’s offset, and the input bias current is now in the range of several tens of microamps. This behavior is illustrated in Figure 25 and Figure 26. Normal operation resumes when the common-mode voltage goes below the 3 V from the positive supply threshold. The output transistors have circuitry included to limit the extent of their saturation when the output is overdriven. This improves output recovery time. A plot of the output recovery time for the AD8067 used as a G = +10 buffer is shown in Figure 17. VCC VTHRESHOLD RF SWITCH CONTROL +VOS– RG TO REST OF AMP VCC VCC VN VP – + VOUT – IB– – VI + RS + VEE VEE IB + Figure 44. Op Amp DC Error Sources VEE Figure 45. Simplified Input Schematic Rev. 0 | Page 17 of 24 VBIAS AD8067 Input Protection The inputs of the AD8067 are protected with back-to-back diodes between the input terminals as well as ESD diodes to either power supply. The result is an input stage with picoamp level input currents that can withstand 2 kV ESD events (human body model) with no degradation. Excessive power dissipation through the protection devices will destroy or degrade the performance of the amplifier. Differential voltages greater than 0.7 V will result in an input current of approximately (| V+ – V– | – 0.7 V)/(RI + RG)), where RI and RG are the resistors (see Figure 46). For input voltages beyond the positive supply, the input current will be about (VI – VCC – 0.7 V)/RI. For input voltages beyond the negative supply, the input current will be about (VI – VEE + 0.7 V)/RI. For any of these conditions, RI should be sized to limit the resulting input current to 50 mA or less. – VI + RI AD8067 RI > ( |V+ – V– | –0.7V)/50mA FOR LARGE |V+ – V– | RG RF RI > (VI – VEE + 0.7V)/50mA RI > (VI – VCC – 0.7V)/50mA FOR VI BEYOND + SUPPLY VOLTAGES VOUT – Figure 46. Current Limiting Resistor Capacitive Load Drive Capacitive load introduces a pole in the amplifier loop response due to the finite output impedance of the amplifier. This can cause excessive peaking and ringing in the response. The AD8067 with a gain of +10 will handle up to a 30 pF capacitive load without an excessive amount of peaking (see Figure 8). If greater capacitive load drive is required, consider inserting a small resistor in series with the load (24.9 Ω is a good value to start with). Capacitive load drive capability also increases as the gain of the amplifier increases. Layout, Grounding, and Bypassing Considerations LAYOUT In extremely low input bias current amplifier applications, stray leakage current paths must be kept to a minimum. Any voltage differential between the amplifier inputs and nearby traces will set up a leakage path through the PCB. Consider a 1 V signal and 100GΩ to ground present at the input of the amplifier. The resultant leakage current is 10 pA; this is ten times the input bias current of the amplifier. Poor PCB layout, contamination, and the board material can create large leakage currents. Common contaminants on boards are skin oils, moisture, solder flux, and cleaning agents. Therefore, it is imperative that the board be thoroughly cleaned and the board surface be free of contaminants to fully take advantage of the AD8067’s low input bias currents. To significantly reduce leakage paths, a guard ring/shield around the inputs should be used. The guard ring circles the input pins and is driven to the same potential as the input signal, thereby reducing the potential difference between pins. For the guard ring to be completely effective, it must be driven by a relatively low impedance source and should completely surround the input leads on all sides, above, and below, using a multilayer board (see Figure 47). The SOT-23-5 package presents a challenge in keeping the leakage paths to a minimum. The pin spacing is very tight, so extra care must be used when constructing the guard ring (see Figure 48 for recommended guard-ring construction). GUARD RING GUARD RING NON-INVERTING INVERTING Figure 47. Guard-Ring Configurations VOUT AD8067 +V VOUT AD8067 –V –V +IN –IN INVERTING +IN –IN NONINVERTING Figure 48. Guard-Ring Layout SOT-23-5 Rev. 0 | Page 18 of 24 +V AD8067 GROUNDING POWER SUPPLY BYPASSING To minimize parasitic inductances and ground loops in high speed, densely populated boards, a ground plane layer is critical. Understanding where the current flows in a circuit is critical in the implementation of high speed circuit design. The length of the current path is directly proportional to the magnitude of the parasitic inductances and thus the high frequency impedance of the path. Fast current changes in an inductive ground return will create unwanted noise and ringing. The length of the high frequency bypass capacitor leads is critical. A parasitic inductance in the bypass grounding will work against the low impedance created by the bypass capacitor. Because load currents flow from supplies as well as ground, the load should be placed at the same physical location as the bypass capacitor ground. For large values of capacitors, which are intended to be effective at lower frequencies, the current return path length is less critical. Power supply pins are actually inputs and care must be taken to provide a clean, low noise dc voltage source to these inputs. The bypass capacitors have two functions: 1. Provide a low impedance path for unwanted frequencies from the supply inputs to ground, thereby reducing the effect of noise on the supply lines 2. Provide localized charge storage—this is usually accomplished with larger electrolytic capacitors Decoupling methods are designed to minimize the bypassing impedance at all frequencies. This can be accomplished with a combination of capacitors in parallel to ground. Good quality ceramic chip capacitors (X7R or NPO) should be used and always kept as close to the amplifier package as possible. A parallel combination of a 0.1 µF ceramic and a 10 µF electrolytic, covers a wide range of rejection for unwanted noise. The 10 µF capacitor is less critical for high frequency bypassing, and in most cases, one per supply line is sufficient. Rev. 0 | Page 19 of 24 AD8067 bandwidth in half will result in a flat frequency response, with about 5% transient overshoot. APPLICATIONS Wideband Photodiode Preamp The preamp’s output noise over frequency is shown in Figure 50. CF Contributor RF 2 × 4kT × RF × f 2 × 1.57 RF × 2 – CM CS IPHOTO + Amp to f1 Vnoise × f 1 Amp (f2–f1) Vnoise × Amp (Past f2) Vnoise × VOUT CD RSH = 1011Ω CM VB AD8067 C F + CS RF RMS Noise (µV)1 Expression 152 4.3 (C S + C M + C F + 2C D ) × CF (C S + C M + C F + 2C D ) × CF f 2 – f1 f 3 × 1.57 RSS Total 96 684 708 Table 2. RMS Noise Contributions of Photodiode Preamp Figure 49. Wideband Photodiode Preamp 1 Figure 49 shows an I/V converter with an electrical model of a photodiode. RMS noise with RF = 50 kΩ, CS = 0.67 pF, CF = 0.33 pF, CM = 1.5 pF, and CD = 2.5 pF. The basic transfer function is: 1 + sC F RF f2 = where IPHOTO is the output current of the photodiode, and the parallel combination of RF and CF sets the signal bandwidth. The stable bandwidth attainable with this preamp is a function of RF, the gain bandwidth product of the amplifier, and the total capacitance at the amplifier’s summing junction, including CS and the amplifier input capacitance. RF and the total capacitance produce a pole in the amplifier’s loop transmission that can result in peaking and instability. Adding CF creates a zero in the loop transmission that compensates for the pole’s effect and reduces the signal bandwidth. It can be shown that the signal bandwidth resulting in a 45° phase margin (f(45)) is defined by the expression: f(45 ) = GBP 2 π × RF × C S GBP is the unit gain bandwidth product, RF is the feedback resistance, and CS is the total capacitance at the amplifier summing junction (amplifier + photodiode + board parasitics). VOLTAGE NOISE – nV/ Hz VOUT = 1 f1 = 2 π R (C + C + C + 2C ) F F S M D I PHOTO × RF GBP f3 = (C + C + 2C + C )/C S M D F F RF NOISE f2 VEN (C F + C S + C M + 2C D )/C F f3 f1 VEN NOISE DUE TO AMPLIFIER FREQUENCY – Hz Figure 50. Photodiode Voltage Noise Contributions Figure 51 shows the AD8067 configured as a transimpedance photodiode amplifier. The amplifier is used in conjunction with a JDS Uniphase photodiode detector. This amplifier has a bandwidth of 9.6 MHz as shown in Figure 52 and is verified by the design equations shown in Figure 50. The value of CF that produces f(45) can be shown to be: CF = 1 2πRFCF CS 2π × RF × GBP The frequency response in this case will show about 2 dB of peaking and 15% overshoot. Doubling CF and cutting the Rev. 0 | Page 20 of 24 AD8067 Using the AD8067 at Gains of Less Than 8 0.33pF 49.9kΩ +5V 10µF 0.1µF –5V 50Ω AD8067 EPM 605 LL The signal and noise gain equations for a noninverting amplifier are shown below. 10µF 0.33pF NOTES ID @ –5V = 0.074nA CD @ –5V = 0.690pF RB @ 1550nm = –49dB VOUT A common technique used to stabilize decompensated amplifiers is to increase the noise gain, independent of the signal gain. The AD8067 can be used for signal gains of less than 8, provided that proper care is taken to ensure that the noise gain of the amplifier is set to at least the recommended minimum signal gain of 8 (See Figure 54). 49.9kΩ 0.1µF –5V Figure 51. Photodiode Preamplifier Signal Gain = 1 + R3 R1 Noise Gain = 1 + R3 R1 Test data for the preamp is shown in Figure 52 and Figure 53. The addition of resistor R2 modifies the noise gain equation, as shown below. Note the signal gain equation has not changed. 100 TRANSIMPEDANCE GAIN – dB 95 Noise Gain = 1 + 90 R3 R1 || R2 R3 600Ω 85 +5V 80 C1 10µF 75 R1 301Ω 70 65 VIN 60 0.01 0.1 1 FREQUENCY – MHz 10 4 R2 50Ω 3 5 AD8067 2 100 Figure 52. Photodiode Preamplifier Frequency Response –5V C2 0.1µF 1 R4 51Ω C3 10µF VOUT RL C4 0.1µF Figure 54. Gain of Less than 2 Schematic C1 RISE 31.2ns T C1 FALL 31.6ns CH1 500mV M 50ns CH1 This technique allows the designer to use the AD8067 in gain configurations of less than 8. The drawback to this type of compensation is that the input noise and offset voltages are also amplified by the value of the noise gain. In addition, the distortion performance will be degraded. To avoid excessive overshoot and ringing when driving a capacitive load, the AD8067 should be buffered by a small series resistor; in this case, a 51 Ω resistor was used. 830mV Figure 53. Photodiode Preamplifier Pulse Response Rev. 0 | Page 21 of 24 AD8067 VOUT Reference network: VIN T V+REF − 3 dB Bandwidth = 1 2π(R2 || R 3)C 2 Resistors R4 and R1 set the gain, in this case an inverting gain of 10 was selected. In this application, the input and output bandwidths were set for approximately 10 Hz. The reference network was set for a tenth of the input and output bandwidth, at approximately 1 Hz. CH1 200mV CH2 200mV M 50ns CH1 R4 2.7kΩ 288mV Figure 55. Gain of 2 Pulse Response C1 47µF Single-Supply Operation VIN R1 300Ω 4 +5V C3 10µF 5 C4 0.1µF AD8067 The AD8067 is well suited for low voltage single-supply applications, given its N-channel JFET input stage and rail-to-rail output stage. It is fully specified for 5 V supplies. Successful singlesupply applications require attention to keep signal voltages within the input and output headroom limits of the amplifier. The input stage headroom extends to 1.7 V (minimum) on a 5 V supply. The center of the input range is 0.85 V. The output saturation limit defines the hard limit of the output headroom. This limit depends on the amount of current the amplifier is sourcing or sinking, as shown in Figure 29. Traditionally, an offset voltage is introduced in the input network replacing ground as a reference. This allows the output to swing about a dc reference point, typically midsupply. Attention to the required headroom of the amplifier is important, in this case the required headroom from the positive supply is 3 V; therefore 1.5 V was selected as a reference, which allows for a 100 mV signal at the input. Figure 56 shows the AD8067 configured for 5 V supply operation with a reference voltage of 1.5 V. Capacitors C1 and C5 ac-couple the signal into an out of the amplifier and partially determine the bandwidth of the input and output structures. VINPUT – 3 dB Bandwidth = VOUTPUT – 3 dB Bandwidth = 1 2πR1C1 3 +5V R2 70kΩ C5 15µF VOUT 1 2 R3 30kΩ RL 1kΩ C2 6.8µF Figure 56. Single-Supply Operation Schematic High Gain, High Bandwidth Composite Amplifier The composite amplifier takes advantage of combining key parameters that may otherwise be mutually exclusive of a conventional single amplifier. For example, most precision amplifiers have good dc characteristics but lack high speed ac characteristics. Composite amplifiers combine the best of both amplifiers to achieve superior performance over their single op amp counterparts. The AD8067 and the AD8009 are well suited for a composite amplifier circuit, combining dc precision with high gain and bandwidth. The circuit runs off a ±5 V power supply at approximately 20 mA of bias current. With a gain of approximately 40 dB, the composite amplifier offers <1 pA input current, a gain bandwidth product of 6.1 GHz, and a slew rate of 630 V/µsec. 1 2πRL C 5 Resistors R2 and R3 set a 1.5 V output bias point for the output signal to swing about. It is critical to have adequate bypassing to provide a good ac ground for the reference voltage. Generally the bandwidth of the reference network (R2, R3, and C2) is selected to be one tenth that of the input bandwidth. This ensures that any frequencies below the input bandwidth do not pass through the reference network into the amplifier. Rev. 0 | Page 22 of 24 AD8067 R2 4.99kΩ C1 10µF +5V R1 51.1Ω INPUT 4 5 AD8067 3 2 –5V C2 1 0.1µF C3 10µF C4 0.1µF 3 C5 5pF 7 AD8009 6 C8 0.1µF 4 C9 10µF C10 0.001µF –5V C11 0.1µF 2 C1 AMPL 4V C7 10µF C6 +5V 0.001µF R4 200Ω OUTPUT T R5 50Ω CH1 1V R3 21.5Ω M 25ns CH1 0V Figure 59. Large Signal Response Figure 57. AD8067/AD8009 Composite Amplifier AV = 100, GBWP = 6.1 GHz The composite amplifier is set for a gain of 100. The overall gain is set by the following equation: C1 AMPL 480mV VO R2 = +1 VI R1 T The output stage is set for a gain of +10; therefore, the AD8067 has an effective gain of +10, thereby allowing it to a maintain bandwidth in excess of 55 MHz. The circuit can be tailored for different gain values; keeping the ratios roughly the same will ensure that the bandwidth integrity is maintained. Depending on the board layout, capacitor C5 may be required to reduce ringing on the output. The gain bandwidth and pulse responses are shown in Figure 58, Figure 59, and Figure 60. Layout of this circuit requires attention to the routing and length of the feedback path. It should be kept as short as possible to minimize stray capacitance. 44 42 40 38 dB 36 34 32 30 28 26 24 0.1 1 10 FREQUENCY – MHz 100 Figure 58. Gain Bandwidth Response Rev. 0 | Page 23 of 24 CH1 200mV M 25ns CH1 Figure 60. Small Signal Response 0V AD8067 OUTLINE DIMENSIONS 2.90 BSC 5 4 2.80 BSC 1.60 BSC 1 2 3 PIN 1 0.95 BSC 1.90 BSC 1.30 1.15 0.90 1.45 MAX 0.15 MAX 0.50 0.30 SEATING PLANE 0.22 0.08 10° 0° 0.60 0.45 0.30 COMPLIANT TO JEDEC STANDARDS MO-178AA Figure 61. 5-Lead Plastic Surface Mount Package [SOT-23} (RT-5) Dimensions shown in millimeters 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. Ordering Guide Model AD8067ART-REEL AD8067ART-REEL7 AD8067ART-R2 Temperature Range –40°C to +85°C –40°C to +85°C –40°C to +85°C Package Description 5-Lead SOT-23 5-Lead SOT-23 5-Lead SOT-23 Table 3. Ordering Guide © 2002 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective companies. Printed in the U.S.A. C03205-0-11/02(0) Rev. 0 | Page 24 of 24 Package Outline RT-5 RT-5 RT-5 Branding Information HAB HAB HAB