AD Rev. D. Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for. AD Low Cost Instrumentation Amplifier FEATURES Easy to Use Low Cost Solution Higher Performance than Two or Three Op Amp Design Unity Gain with . FEATURES Easy to use Low cost solution Higher performance than two or three op amp design Unity gain with no external resistor Optional gains with one.

Author: Sajas Dujin
Country: Uganda
Language: English (Spanish)
Genre: Automotive
Published (Last): 15 November 2015
Pages: 313
PDF File Size: 18.23 Mb
ePub File Size: 13.32 Mb
ISBN: 875-1-95542-134-2
Downloads: 93465
Price: Free* [*Free Regsitration Required]
Uploader: Gobar

Documents Flashcards Grammar checker. Science Physics Electronics AD data sheet advertisement. Or for a gain of 1, no external resistor is required.

The AD datxsheet low cost, discrete, two or three op amp instrumentation amplifier designs and offers good commonmode rejection, superior linearity, temperature stability, reliability, and board area consumption.

The low cost of the AD eliminates the need to design discrete instrumentation amplifiers to meet stringent cost targets. While providing a lower cost solution, it also provides performance and space improvements. 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 which may result from its datashert.

No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P. BoxNorwood, MAU. Specifications subject to change without notice. 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.

Electrostatic charges as high as V readily accumulate on the human body and test equipment ad6222 can discharge without detection. Although the AD features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to dtaasheet energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.

Change in Input Offset Voltage vs. Voltage Noise Spectral Density vs. Current Noise Spectral Density vs. Settling Time to 0. Output Voltage Swing vs. Load Resistance Figure A Typical Application Error Budget The AD is a monolithic instrumentation amplifier based on a modification of the classic three op-amp approach.


Absolute value trimming allows the user to program gain accurately to 0. Monolithic construction and laser wafer trimming allow the tight matching and tracking of circuit components, thus insuring its performance. In a typical application shown in Figure 14, a af622 of 10 is required to receive and amplify a 0—20 mA signal from the AD current transmitter.

In applications where transmission is over long distances, line impedance can be significant so that differential voltage measurement is essential. The error budget detailed in Table I shows how to calculate the effect various error sources have on circuit accuracy. The input transistors Q1 and Q2 provide a single differentialpair bipolar input for high precision.

Feedback through the Q1-A1-R1 loop and the Q2-A2-R2 loop maintains constant collector current of the input devices Q1, Q2 thereby impressing the input voltage across the external gain-setting resistor RG.

The unity-gain subtracter A3 removes any common-mode signal, yielding a single-ended output referred to the REF pin potential. The AD provides greater accuracy at lower cost.

This level of datasheeg rejection would however degrade significantly over temperature due to the drift mismatch of the discrete resistors. The value of RG also determines the transconductance of the preamp stage. As RG is reduced for larger gains, the transconductance increases asymptotically to that of the input transistors.

AD Datasheet and Product Info | Analog Devices

This has three important advantages: The internal gain resistors, R1 and R2, are trimmed to an absolute value of Table II shows required values of R G for various gains. The output error is divided by G when referred to the input. In practice, the input errors dominate at high gains and the output errors dominate at low gains. The total VOS for a given gain is calculated as: The circuit of Figure 15 is recommended for AD series inamps and provides good RFI suppression at the expense of reducing the differential bandwidth.

In addition, this RC input network also provides additional input overload protection see input protection section. It provides a direct means of injecting a precise offset to the output, with an allowable range of 2 V within the supply voltages. Parasitic resistance should be kept to a minimum for optimum CMR.


This is true for all gains and power on and off, which is particularly important since the signal source and amplifier may be powered separately.

For input overloads beyond the supplies, clamping the inputs to the supplies using a diode such as an IN will reduce the required resistance, yielding lower noise. C3 insures that any RF signals are common mode the same on both in-amp inputs and are not applied differentially.

This low pass network has a —3 dxtasheet BW equal to: Using a C3 value of 0. When operating at a gain ofthe typical dc offset shift over a frequency range of 1 Hz to 20 MHz will be less than 1.

Low Cost Instrumentation Amplifier AD622 Data Sheet FEATURES

The 3 dB signal bandwidth of this circuit may be increased to Hz by reducing resistors R1 and R2 to 2. This circuit should be built using a PC board with a ground plane on both sides. All component leads should be made as short as possible.

Input bias currents datqsheet those currents necessary to bias the input transistors of an amplifier. Refer to the Instrumentation Amplifier Application Guide free from Analog Devices for more information regarding in amp applications. The use of ground planes is recommended to minimize the impedance of a622 returns and hence the size of dc errors.

In order to isolate low level analog signals from a noisy digital environment, many data-acquisition components have separate analog and digital ground returns Figure Maximum isolation between analog and digital is achieved by connecting the ground planes back at the supplies. The digital return currents from the ADC which flow in the analog ground plane will in general have a negligible effect on noise performance. Problem Set 3 Due Friday 5pmFebruary 24, Lab 9 in this note. Review of LR circuits.

Using the passive sign. Physics Lab 5 Prelab Exercise: