ADA4950-2 AD [Analog Devices], ADA4950-2 Datasheet
ADA4950-2
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ADA4950-2 Summary of contents
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... The output common-mode voltage is user adjustable by means of an internal common-mode feedback loop, allowing the ADA4950-1/ ADA4950-2 output to match the input of the ADC. The internal feedback loop also provides exceptional output balance as well as suppression of even-order harmonic distortion products. ...
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... ADA4950-1/ADA4950-2 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagrams ............................................................. 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3 ±5 V Operation ............................................................................. Operation ............................................................................... 5 Absolute Maximum Ratings ............................................................ 7 Thermal Resistance ...................................................................... 7 Maximum Power Dissipation ..................................................... 7 ESD Caution .................................................................................. 7 Pin Configurations and Function Descriptions ........................... 8 Typical Performance Characteristics ............................................. 9 Test Circuits ..................................................................................... 16 Terminology .................................................................................... 17 REVISION HISTORY 5/09— ...
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... ADA4950-2 Slew Rate Settling Time to 0.1% Overdrive Recovery Time NOISE/HARMONIC PERFORMANCE Second Harmonic Third Harmonic IMD3 Voltage Noise (Referred to Output) Crosstalk (ADA4950-2) INPUT CHARACTERISTICS Offset Voltage (Referred to Input) Input Capacitance Input Common-Mode Voltage Range CMRR Open-Loop Gain OUTPUT CHARACTERISTICS Output Voltage Swing ...
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... ADA4950-1/ADA4950 Performance OCM OUT, cm Table 2. Parameter V DYNAMIC PERFORMANCE OCM −3 dB Small-Signal Bandwidth −3 dB Large-Signal Bandwidth Slew Rate Input Voltage Noise (Referred to Input) V INPUT CHARACTERISTICS OCM Input Voltage Range Input Resistance Input Offset Voltage V CMRR OCM Gain General Performance Table 3. ...
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... ADA4950-2 Slew Rate Settling Time to 0.1% Overdrive Recovery Time NOISE/HARMONIC PERFORMANCE Second Harmonic Third Harmonic IMD3 Voltage Noise (Referred to Input) Crosstalk (ADA4950-2) INPUT CHARACTERISTICS Offset Voltage (Referred to Input) Input Capacitance Input Common-Mode Voltage Range CMRR Open-Loop Gain OUTPUT CHARACTERISTICS Output Voltage Swing ...
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... ADA4950-1/ADA4950 Performance OCM OUT, cm Table 5. Parameter V DYNAMIC PERFORMANCE OCM −3 dB Small-Signal Bandwidth −3 dB Large-Signal Bandwidth Slew Rate Input Voltage Noise (Referred to Input) V INPUT CHARACTERISTICS OCM Input Voltage Range Input Resistance Input Offset Voltage V CMRR OCM Gain General Performance Table 6. ...
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... EIA/JESD51-7. Table 8. Thermal Resistance Package Type ADA4950-1, 16-Lead LFCSP (Exposed Pad) ADA4950-2, 24-Lead LFCSP (Exposed Pad) MAXIMUM POWER DISSIPATION The maximum safe power dissipation in the ADA4950-x package is limited by the associated rise in junction temperature (T the die. At approximately 150°C, which is the glass transition temperature, the plastic changes its properties ...
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... Pin No. Mnemonic 1 +INB 2 +INA 3 −INA 4 −INB OCM 10 +OUT 11 −OUT − (EPAD) Exposed Paddle (EPAD) Table 10. ADA4950-2 Pin Function Descriptions Pin No. Mnemonic 1 −INA1 2 −INB1 +INB2 6 +INA2 7 −INA2 8 −INB2 OCM2 12 +OUT2 13 −OUT2 ...
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... 53.6 Ω (when used 1000 1000 Figure 11. Large-Signal Frequency Response for Various Supplies 1000 Figure 12. Large-Signal Frequency Response for Various Temperatures Rev Page ADA4950-1/ADA4950 kΩ, unless otherwise noted. Refer to Figure p-p 1 OUT 53.6Ω ...
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... ADA4950-1/ADA4950 100mV p-p OUT – 1kΩ 200Ω –2 L –3 –4 –5 –6 –7 – 100 FREQUENCY (MHz) Figure 13. Small-Signal Frequency Response at Various Loads 100mV p-p 1 OUT – –2.5VDC OCM –2 OCM V = +2.5VDC OCM – ...
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... Figure 24. Harmonic Distortion vs. Frequency at Various Gains Rev Page ADA4950-1/ADA4950-2 0 p-p OUT, dm 0.4 0.3 0.2 0.1 0 ADA4950- 1kΩ L ADA4950- 200Ω L ADA4950-2, AMP 1kΩ L ADA4950-2, AMP 200Ω L ADA4950-2, AMP 1kΩ L ADA4950-2, AMP 200Ω 100 FREQUENCY (MHz ...
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... ADA4950-1/ADA4950-2 – p-p OUT, dm –50 –60 HD2, ±5V HD3, ±5V –70 HD2, ±2.5V HD3, ±2.5V –80 –90 –100 –110 –120 –130 –140 0.1 1 FREQUENCY (MHz) Figure 25. Harmonic Distortion vs. Frequency at Various Supplies – p-p OUT, dm –40 –50 HD2 AT 10MHz –60 HD3 AT 10MHz HD2 AT 30MHz – ...
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... 100mV p-p IN, dm PSRR+ PSRR– 10 100 FREQUENCY (MHz) Figure 35. PSRR vs. Frequency R = 200Ω p-p IN, dm AMPLIFIER 2 TO AMPLIFIER 1 AMPLIFIER 1 TO AMPLIFIER 2 10 100 FREQUENCY (MHz) Figure 36. Crosstalk vs. Frequency, ADA4950 –45 –90 –135 –180 –225 –270 10G 1000 1000 ...
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... ADA4950-1/ADA4950-2 0 INPUT SINGLE-ENDED, 50Ω LOAD TERMINATION OUTPUT DIFFERENTIAL, 100Ω SOURCE TERMINATION S11: SINGLE-ENDED-TO-SINGLE-ENDED –10 S22: DIFFERENTIAL-TO-DIFFERENTIAL R = 200Ω 100mV p-p –20 IN, dm –30 S11 –40 S22 –50 – FREQUENCY (MHz) Figure 37. Return Loss ( vs. Frequency 11 22 ...
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... V 0.4 5 0.3 4 0.2 0 –0.1 –0.2 1 –0.3 0 –0.4 –0.5 – Rev Page ADA4950-1/ADA4950 0pF 0.9pF 1.8pF 2.7pF TIME (ns TIME (ns) Figure 47. V Large-Signal Pulse Response OCM = +1V DC ...
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... ADA4950-1/ADA4950-2 TEST CIRCUITS DC-COUPLED SOURCE V IN DIFFERENTIAL NETWORK ANALYZER SOURCE 49.9Ω 49.9Ω DC-COUPLED SOURCE 50Ω LOW-PASS FILTER V IN 25.5Ω 250Ω 500Ω NC 500Ω 50Ω 53.6Ω V ADA4950-x OCM 500Ω 0.1µF 25.5Ω 250Ω 500Ω NC Figure 49. Equivalent Basic Test Circuit +5V 250Ω ...
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... Any imbalances in amplitude or phase produce an undesired common-mode signal at the amplifier output. Output balance error is defined as the magnitude of the output common-mode voltage divided by the magnitude of the output differential mode voltage. Output Rev Page ADA4950-1/ADA4950 )/2 +OUT −OUT Δ V ...
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... ADA4950-1/ADA4950-2 THEORY OF OPERATION The ADA4950-x differs from conventional op amps in that it has two outputs whose voltages move in opposite directions and an additional input Like an op amp, it relies on high open-loop OCM gain and negative feedback to force these outputs to the desired voltages. The ADA4950-x behaves much like a standard voltage ...
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... (4kTR ) 1 1/2 (4kTR ) 1 F2 Rev Page ADA4950-1/ADA4950-2 Ω 500 = 3 Ω Ω || 250 depend on G nIN− by the noise gain, G nIN equation that follows Table 13). The noise pin When the feedback OCM nCM is common mode. Each of the four ...
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... ADA4950-1/ADA4950-2 Table 12. Differential Input, DC-Coupled Nominal Linear Gain R (Ω 500 2 500 3 500 Table 13. Single-Ended, Ground-Referenced Input, DC-Coupled, R Nominal Linear Gain R (Ω 500 2 500 3 500 || Similar to the case of a conventional op amp, the output noise voltage densities can be estimated by multiplying the input- referred terms at +INx and − ...
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... The desired differential output in this example p-p because the terminated input signal p-p and the closed- loop gain = 1. The actual differential output voltage, however, is equal to (1.03 V p-p)(500/525.5) = 0.98 V p-p. Rev Page ADA4950-1/ADA4950-2 in the upper feedback G in the lower loop due to the G in the lower loop ...
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... ADA4950-1/ADA4950-2 INPUT COMMON-MODE VOLTAGE RANGE The ADA4950-x input common-mode voltage range is shifted down by approximately one contrast to other ADC BE drivers with centered input ranges such as the ADA4939-x. The downward-shifted input common-mode range is especially suited to dc-coupled, single-ended-to-differential, and single- supply applications. ...
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... PCB traces close together, and twist any differential wiring to minimize loop area. Doing this reduces radiated energy and makes the circuit less susceptible to interference. 1.30 0.80 Figure 61. Recommended PCB Thermal Attach Pad (Dimensions in Millimeters) 1.30 0.30 PLATED VIA HOLE Rev Page ADA4950-1/ADA4950-2 1.30 0.80 ...
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... ADA4950-1/ADA4950-2 HIGH PERFORMANCE ADC DRIVING The ADA4950-x is ideally suited for broadband dc-coupled applications. The circuit in Figure 63 shows a front-end connection for an ADA4950-1 driving an with dc coupling on the ADA4950-1 input and output. (The AD9245 achieves its optimum performance when driven differentially.) The ADA4950-1 eliminates the need for a transformer to drive the ADC and performs a single-ended-to- differential conversion and buffering of the driving signal ...
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... Figure 65. 24-Lead Lead Frame Chip Scale Package [LFCSP_VQ × Body, Very Thin Quad (CP-24-1) Dimensions shown in millimeters Package Description Package Option 16-Lead LFCSP_VQ CP-16-2 16-Lead LFCSP_VQ CP-16-2 16-Lead LFCSP_VQ CP-16-2 24-Lead LFCSP_VQ CP-24-1 24-Lead LFCSP_VQ CP-24-1 24-Lead LFCSP_VQ CP-24-1 Rev Page ADA4950-1/ADA4950-2 0.50 0.40 0.30 PIN 1 INDICATOR * 1. 1.30 SQ 1.15 PAD 4 5 0.25 MIN PIN 1 INDICATOR ...
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... ADA4950-1/ADA4950-2 NOTES Rev Page ...
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... NOTES Rev Page ADA4950-1/ADA4950-2 ...
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... ADA4950-1/ADA4950-2 NOTES ©2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07957-0-5/09(0) Rev Page ...