The AD845 is a fast, precise, N channel JFET input, monolithic operational amplifier. It is fabricated using Analog Devices' complementary bipolar (CB) process. Advanced laser-wafer trimming technology enables the very low input offset voltage and offset voltage drift performance to be realized. This precision, when coupled with a slew rate of 100 V/µs, a stable unity-gain bandwidth of 16 MHz, and a settling time of 350 ns 0.01%-while driving a parallel load of 100 pF and 500 Ohm- represents a combination of features unmatched by any FET input IC amplifier. The AD845 can easily be used to upgrade many existing designs which use BiFET or FET input hybrid amplifiers and, in some cases, those which use bipolar input op amps.
The AD845 is ideal for use in applications such as active filters, high speed integrators, photo diode preamps, sample-and-hold amplifiers, log amplifiers, and in buffering A/D and D/A converters. The 250 µV max input offset voltage makes offset nulling unnecessary in many applications. The common-mode rejection ratio of 110 dB over a ±10 V input voltage range represents exceptional performance for a JFET input high speed op amp. This, together with a minimum open-loop gain of 250 V/mV ensures that 12-bit performance is achieved, even in unity-gain buffer circuits.
The AD845 conforms to the standard op amp pinout except that offset nulling is to V+. The AD845J and AD845K grade devices are available specified to operate over the commercial 0°C to +70°C temperature range. AD845A and AD845B devices are specified for operation over the -40°C to +85°C industrial temperature range. The AD845S is specified to operate over the full military temperature range of -55°C to +125°C. Both the industrial and military versions are available in 8-pin cerdip packages. The commercial version is available in an 8-pin plastic mini-DIP and 16-pin SOIC; "J" and "S" grade chips are also available.
|Title||Content Type||File Type|
|AD845: Precision, 16 MHz CBFET Op Amp Data Sheet (Rev E, 10/2003) (pdf, 211 kB)||Data Sheets|
|AD845: Military Data Sheet (Rev A, 03/2001) (pdf)||Data Sheets|
|AN-581: Biasing and Decoupling Op Amps in Single Supply Applications (pdf, 166 kB)||Application Notes|
AN-402: Replacing Output Clamping Op Amps with Input Clamping Amps
(pdf, 55 kB)
So far most clamping amplifiers have relied upon an output clamping architecture and are called output clamp amps (OCAs). A new architecture called an input clamp amp (ICA) offers superior clamping accuracy and lower distortion.
AN-417: Fast Rail-to-Rail Operational Amplifiers Ease Design Constraints in Low Voltage High Speed Systems
(pdf, 228 kB)
Movement towards lower power supply voltages is driven by the demand that systems consume less and less power coupled with the desire to reduce the number of power supply voltages in the system. The following applications are discussed: Single-Ended and Differential Input ADC Input Circuits, Video Line Driver, Active Filter, HDSL Transceiver, and Transformer Drive Circuits.
|CN-0042: Driving the AD7366/AD7367 Bipolar SAR ADC in Low-Distortion DC-Coupled (pdf, 130 kB)||Circuit Note|
|MT-060: Choosing Between Voltage Feedback and Current Feedback Op Amps (pdf, 62 kB)||Tutorials|
|MT-059: Compensating for the Effects of Input Capacitance on VFB and CFB Op Amps Used in Current-to-Voltage Converters (pdf, 69 kB)||Tutorials|
|MT-058: Effects of Feedback Capacitance on VFB and CFB Op Amps (pdf, 66 kB)||Tutorials|
|MT-056: High Speed Voltage Feedback Op Amps (pdf, 109 kB)||Tutorials|
|MT-053: Op Amp Distortion: HD, THD, THD + N, IMD, SFDR, MTPR (pdf, 104 kB)||Tutorials|
|MT-052: Op Amp Noise Figure: Don't Be Misled (pdf, 60 kB)||Tutorials|
|MT-050: Op Amp Total Output Noise Calculations for Second-Order System (pdf, 38 kB)||Tutorials|
|MT-049: Op Amp Total Output Noise Calculations for Single-Pole System (pdf, 40 kB)||Tutorials|
|MT-048: Op Amp Noise Relationships: 1/f Noise, RMS Noise, and Equivalent Noise Bandwidth (pdf, 81 kB)||Tutorials|
|MT-047: Op Amp Noise (pdf, 72 kB)||Tutorials|
|MT-033: Voltage Feedback Op Amp Gain and Bandwidth (pdf, 251 kB)||Tutorials|
|MT-032: Ideal Voltage Feedback (VFB) Op Amp (pdf, 65 kB)||Tutorials|
A Stress-Free Method for Choosing High-Speed Op Amps
A decision-tree approach to making the critical decision about high-speed op amp selection, including a look at some helpful tools.
ADI Warns Against Misuse of COTS Integrated Circuits
(pdf, 13 kB)
Invites Customer Participation in Creative Mil/Aero System Solutions
Space Qualified Parts List
(pdf, 93 kB)
This document lists 67 (240+) space level products that are available from Analog Devices. Many of the products listed are state-of-the-art data conversion and signal processing products that were previously only available as commercial or military Class B products. Through our Space Products Group and MIL-PRF-38535 certified Level V (Class S) facility, we are pleased to offer these products to the space marketplace.
|RAQs index||Rarely Asked Questions||HTML|
|Glossary of EE Terms||Glossary||HTML|
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This calculator converts between standard units of power measurement and signal strength.
|Utilities and Conversions||HTML|
Power Dissipation vs Die Temp
This tool estimates die temperature and power dissipation based on the supply voltages, ambient temperature, load characteristics, and package thermal data.
|Utilities and Conversions||HTML|
This tool will help with the selection, evaluation and troubleshooting of voltage feedback Op-Amps. It uses typical data to model the behavior of a selected amplifier. It allows a user to select an amplifier, configure a circuit, apply a signal and evaluate the performance. It is useful for checking an amplifier's spec's such as Bandwidth, Slew Rate, Input/Output Range, Gain Error, Load Current, Stability Issues and DC Errors in a given circuit.
|ADIsim Design/Simulation Tools||HTML|
An applet for demonstrating stability effects in opamp buffers.
|AD845 SPICE Macro-Model||SPICE Models||HTML|
Symbols and Footprints— Analog Devices offers Symbols & Footprints which are compatible with a large set of today’s CAD systems for broader and easier support.
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.