ADA4941-1 Analog Devices, ADA4941-1 Datasheet
ADA4941-1
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ADA4941-1 Summary of contents
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... The ADA4941-1 is manufactured on ADI’s proprietary second- generation XFCB process, which enables the amplifier to achieve 18-bit performance on low supply currents. The ADA4941-1 is available in a small 8-lead LFCSP as well as a standard 8-lead SOIC and is rated to work over the extended industrial temperature range, −40°C to +125°C. ...
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... ADA4941-1 TABLE OF CONTENTS Features .............................................................................................. 1 Applications ....................................................................................... 1 www.datasheet4u.com Functional Block Diagram .............................................................. 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications ..................................................................................... 3 Absolute Maximum Ratings ............................................................ 6 Thermal Resistance ...................................................................... 6 ESD Caution .................................................................................. 6 Pin Configuration and Function Descriptions ............................. 7 Typical Performance Characteristics ............................................. 8 Theory of Operation ...................................................................... 15 Basic Operation .......................................................................... 15 DC Error Calculations ............................................................... 16 REVISION HISTORY 3/09—Rev Rev. A Change to Gain Error Drift Parameter, Table 1 ...
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... OS Each single-ended output 20% overshoot 200 mV p-p O PSRR = V /Δ OS Disabled, DIS = High Enabled, DIS = Low Disabled, DIS = High Enabled, DIS = Low Rev Page ADA4941-1 Min Typ Max Unit 21 30 MHz 4.6 6.5 MHz 320/650 ns 22 V/μs 300 ns − ...
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... ADA4941 25° OUT+ connected 2 Table 2. Parameter DYNAMIC PERFORMANCE −3 dB Bandwidth www.datasheet4u.com Overdrive Recovery Time Slew Rate Settling Time 0.005% NOISE/DISTORTION PERFORMANCE Harmonic Distortion RTO Voltage Noise Input Current Noise DC PERFORMANCE Differential Output Offset Voltage Differential Input Offset Voltage Drift ...
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... Each single-ended output 20% overshoot 200 mV p-p O PSRR = V /Δ OS Disabled, DIS = High Enabled, DIS = Low Disabled, DIS = High Enabled, DIS = Low Rev Page ADA4941-1 Min Typ Max Unit 23 32 MHz 5.2 7.5 MHz 200/650 ns 26 V/μs 980 ns − ...
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... Even temporarily exceeding this temperature limit can change the stresses that the package exerts on the die, permanently shifting the parametric performance of the ADA4941-1. Exceeding a junction temperature of 150°C for an extended period can result in changes in the silicon devices potentially causing failure ...
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... FB 1 REF OUT+ 4 Figure 4. Pin Configuration Mnemonic Description FB Feedback Input REF Reference Input V+ Positive Power Supply OUT+ Noninverting Output OUT− Inverting Output V− Negative Power Supply DIS Disable IN Input Rev Page DIS 7 V– 6 OUT– 5 ADA4941-1 ...
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... ADA4941-1 TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise noted www.datasheet4u.com –1 –2 –3 –4 –5 –6 –7 –8 –9 –10 –11 –12 –13 –14 – +3V S – FREQUENCY (MHz) Figure 5. Small Signal Frequency Response for Various Power Supplies ...
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... Figure 15. Frequency Response for Various Output Amplitudes – p VREF = MIDSUPPLY –80 –90 –100 HD3 –110 –120 –130 HD2 HD2 –140 0 100 FREQUENCY (kHz) Figure 16. Distortion vs. Frequency for Various Loads ADA4941 p 1000 = 0.1V p-p 1000 R = 2kΩ 1kΩ 500Ω L 1000 ...
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... ADA4941-1 – 10kHz – –85 www.datasheet4u.com –95 –105 HD3 –115 HD2 –125 HD2 HD3 –135 OUTPUT AMPLITUDE (V p-p) Figure 17. Distortion vs. Output Amplitude for Various Supplies (G = +2) – p-p – VREF = MIDSUPPLY –70 –75 –80 –85 – ...
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... × Figure 27. Settling Time (0.005%), INPUT × OUTPUT 2 0 –2 –4 –6 –8 Figure 28. Input Overdrive Recovery ADA4941-1 200ns/DIV 1.2 0 p-p 0.6 0.3 0 –0.3 –0.6 –0.9 1µs/DIV –1.2 1µs/DIV = +5 V ...
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... ADA4941-1 0 –10 –20 –30 –40 +PSRR www.datasheet4u.com –50 –60 –70 –80 –90 –100 –110 0.001 0.01 0.1 1 FREQUENCY (MHz) Figure 29. Power Supply Rejection Ratio vs. Frequency 3 S– 3 + ± +3V S 1.5 1.0 –40 – TEMPERATURE (°C) Figure 30. Power Supply Current vs. Temperature ...
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... INPUT VOLTAGE WITH RESPECT TO V Figure 39. Input Bias Current vs. Input Voltage 4.0 3 2.5 2.0 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 REFERENCE INPUT VOLTAGE WITH RESPECT TO V Figure 40. REF Input Bias Current vs. REF Input Voltage ADA4941-1 100k ±5V 8.5 9.5 8.0 9.0 10.0 (V) S– VREF = VIN = ±5V 8.0 9.0 10.0 8.5 9.5 (V) S– ...
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... ADA4941 ± www.datasheet4u.com –40 – TEMPERATURE (°C) Figure 41. Disable Supply Current vs. Temperature for Various Supplies 40µs/DIV Figure 42. Disable Assert Time –40 VIN = 50mV p-p –50 –60 –70 –80 –90 –100 –110 ...
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... THEORY OF OPERATION The ADA4941 low power, single-ended input, differential output amplifier optimized for driving high resolution ADCs. Figure 47 illustrates how the ADA4941-1 is typically connected. The amplifier is composed of an uncommitted amplifier, A1, www.datasheet4u.com driving a precision inverter, A2. The negative input brought out to Pin 1 (FB), allowing for user-programmable gain ...
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... VON_error = −( VOP_error ) + 2[ V (8) The differential output voltage error V difference between VOP_error and VON_error: V The output offset voltage of each amplifier in the ADA4941-1 also includes the effects of finite common-mode rejection ratio OUT+ 4 (CMRR), power supply rejection ratio (PSRR), and dc open- + VOP – ...
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... REF) S– Rev Page Figure 52 shows the major contributors to the ADA4941-1 differential output voltage noise. The differential output noise mean-square voltage equals the sum of twice the noise mean- square voltage contributions from the noninverting channel (A1), plus the noise mean-square voltage terms associated with the inverting channel (A2) ...
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... ADA4941-1 Table 10. Output Voltage Noise 2.4 Differential Amplifier Shown in Figure 48 Noise Source Typical Value vn_A1 2.1 nV/√Hz ip_A1 1 pA/√Hz www.datasheet4u.com in_A1 1 pA/√Hz √4 kTR 4 nV/√ nV/√Hz √4 kTR G √4 kTR 3.6 nV/√Hz S vn_inverter 9.2 nV/√Hz √R _REF 0 S ip_A2 × R _REF ...
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... FREQUENCY RESPONSE VS. CLOSED-LOOP GAIN The operational amplifiers used in the ADA4941-1 are voltage feedback with an open-loop frequency response that can be approximated with the integrator response, as shown in Figure 53. 100 www.datasheet4u.com 0.001 0.01 0.1 FREQUENCY (MHz) Figure 53. ADA4941-1 Op Amp Open-Loop Gain vs. Frequency For each amplifier, the frequency response can be approximated by the following equations: ⎛ ...
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... For ac signals, rms analysis is required. DISABLE FEATURE The ADA4941-1 includes a disable feature that can be asserted to minimize power consumption in a device that is not needed at a particular time. When asserted, the disable feature does not place the device output in a high impedance or tristate condition ...
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... ADDING A 3-POLE, SALLEN-KEY FILTER The noninverting amplifier in the ADA4941-1 can be used as the buffer amplifier of a Sallen-Key filter. A 3-pole, low-pass filter can be designed to limit the signal bandwidth in front of an ADC. The input signal first passes through the noninverting www.datasheet4u.com stage where it is filtered. The filtered signal is then passed through the inverting stage to obtain the complementary output. 562Ω ...
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... AD8032 amplifiers and applied to the AD7687 REF input, providing a differential input full-scale level The reference voltage is also divided by two and buffered to supply the midsupply REF level of 1.5 V for the ADA4941-1. 562Ω 562Ω VIN 3.9nF ...
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... ADA4941-1YRZ-RL −40°C to +125°C 1 ADA4941-1YRZ-R7 −40°C to +125°C 1 ADA4941-1YCPZ-R2 −40°C to +125°C 1 ADA4941-1YCPZ-RL −40°C to +125°C 1 ADA4941-1YCPZ-R7 −40°C to +125° RoHS Compliant Part. 5.00 (0.1968) 4.80 (0.1890 6.20 (0.2441) 4.00 (0.1574) 1 5.80 (0.2284) 3.80 (0.1497) 4 1.27 (0.0500) BSC 1 ...
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... ADA4941-1 NOTES www.datasheet4u.com ©2006–2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05704-0-3/09(A) Rev Page ...