AD844SQ/883 - 60MHz 2000V/µs Current Feedback Op Amp | Analog Devices
MPN: AD844SQ/883 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $28.5 | $28.50 |
| 10 | $25.4 | $254.00 |
| 100 | $22.1 | $2,210.00 |
| 500 | $19.75 | $9,875.00 |
| 1,000 | $18.2 | $18,200.00 |
AD844SQ/883 Overview
A current-feedback op amp (CFA) is a high-speed amplifier topology in which the inverting input is a low-impedance node and the small-signal bandwidth is set primarily by the external feedback resistor, not by the closed-loop gain. CFAs therefore offer wider bandwidth at higher gains and faster slew rates than classic voltage-feedback amplifiers, at the cost of slightly higher input bias current at the inverting node. The AD844 is widely considered the canonical CFA reference part for video, pulse, and instrumentation designs.
Key headline specifications include 60 MHz small-signal bandwidth at a gain of +1, 33 MHz bandwidth at a gain of +10, a slew rate up to 2000 V/µs, 20 MHz full-power bandwidth at 20 V pk-pk, fast settling on a 10 V step, and 2000 V/µs transient response. The /883B suffix designates parts processed to MIL-STD-883 Class B environmental screening, intended for military, aerospace, and high-reliability industrial programs.
The device is internally compensated and uses external feedback resistors to set closed-loop gain. Its complementary-bipolar output stage can swing to within a few volts of each rail on standard ±15 V supplies, and DC precision is sufficient for many instrumentation paths. The CB process gives the AD844 the combination of bandwidth and DC accuracy that made it a long-running industry reference.
Typical applications include wideband pulse and RF signal-chain building blocks, video line drivers and distribution amplifiers, high-speed current-to-voltage converters for photodiode and DAC outputs, fast sample-and-hold buffers, and military/aerospace signal-conditioning blocks where MIL-STD-883 screening is required. Designers use it wherever a single amplifier must deliver both DC accuracy and multi-MHz large-signal bandwidth.
When designing with the AD844SQ/883, observe that optimum bandwidth is achieved with a feedback resistor of about 1 kΩ, and that the inverting input bias current is appreciably larger than on a precision VFA. Decouple each supply pin with a 0.1 µF ceramic plus a larger tantalum or electrolytic cap placed as close as possible to the package, and keep ground-return paths short to preserve settling performance.
This page synthesizes distributor pricing, MIL-STD-883 screening notes, drop-in and pin-compatible same-package alternatives, and practical CFA design considerations not collected in a single place in the manufacturer datasheet.
Drop-in alternatives for AD844SQ/883 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD844SQ/883 (same form factor and footprint) — differing in Full-Power Bandwidth, Package, RoHS Status, Slew Rate.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD844SQ
✅ Drop-In✓ In Stock
$16.4 / Unit
View Datasheet →AD844BQ
✅ Drop-In📋 Reference alternative (not in catalog)
AD844AQ
✅ Drop-In📋 Reference alternative (not in catalog)
AD844JR-16
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD844SQ/883 Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices, Inc. |
| Product Type | Current-feedback operational amplifier (CFA) |
| Process Technology | Junction-isolated complementary bipolar (CB) |
| Number of Channels | 1 |
| Small-Signal Bandwidth (G=+1) | 60 MHz |
| Small-Signal Bandwidth (G=+10) | 33 MHz |
| Slew Rate | 2000 V/µs |
| Full-Power Bandwidth | 20 MHz at 20 V pk-pk |
| Settling Time (10 V step) | Fast (see datasheet graph) |
| Differential Gain Error (4.4 MHz) | Low (see datasheet) |
| Differential Phase Error (4.4 MHz) | Low (see datasheet) |
| Package | 8-pin CERDIP (Q) through-hole |
| Mounting Type | Through-Hole |
| Screening | MIL-STD-883 Class B (/883B suffix) |
| RoHS Status | Non-compliant (Sn/Pb lead finish, CERDIP package) |
AD844SQ/883 Pin Configuration
| Pin 1 | NC — Not connected (per datasheet) |
| Pin 2 | -INPUT — Inverting input (low-impedance, current-feedback node) |
| Pin 3 | +INPUT — Non-inverting input |
| Pin 4 | V- — Negative power supply |
| Pin 5 | NC — Not connected (per datasheet) |
| Pin 6 | OUTPUT — Amplifier output |
| Pin 7 | V+ — Positive power supply |
| Pin 8 | NC — Not connected (per datasheet) |
Typical Applications
AD844SQ/883 is suitable for 6 applications: Wideband Pulse and RF Signal-Chain Building Block, Video Line Driver and Distribution Amplifier, Fast Current-to-Voltage Converter, High-Speed Sample-and-Hold Buffer, Active Filter and High-Speed Integrator, Military/Aerospace Signal Conditioning.
Wideband Pulse and RF Signal-Chain Building Block
The AD844SQ/883 fits wideband pulse and RF signal-chain building blocks because of its 60 MHz small-signal bandwidth at gain +1, 2000 V/µs slew rate, and 20 MHz full-power bandwidth at 20 V pk-pk. The current-feedback topology holds bandwidth as closed-loop gain increases, so the same amplifier can serve both unity-gain buffer and moderate-gain IF stages without redesign. The MIL-STD-883 screening makes it acceptable for military radar, EW, and avionics signal paths where DC accuracy and bandwidth must coexist on the same die.
Recommended
Video Line Driver and Distribution Amplifier
The AD844SQ/883 is widely used as a video line driver because the AD844 datasheet specifies low differential gain and phase error at 4.43 MHz, the NTSC/PAL sub-carrier. With ±15 V supplies its output swing drives 75 Ω video lines through a back-termination resistor, and the 2000 V/µs slew rate preserves sharp video edges over long cables. Distribution-amplifier cards built around the AD844 typically use one part per channel plus a power splitter for multi-output distribution.
Recommended
Fast Current-to-Voltage Converter
Photodiode and high-speed DAC outputs often require a wideband transimpedance stage, and the AD844SQ/883's low inverting-input impedance and 60 MHz bandwidth make it a strong fit. Placing the photodiode at the inverting input and using a 1 kΩ to 10 kΩ feedback resistor yields a flat-bandwidth I-to-V stage that easily handles pulse responses from PIN diodes or Si photodiodes. The MIL-STD-883 screening lets the same converter be deployed in lidar receivers and military optronics without a separate BOM line.
Recommended
High-Speed Sample-and-Hold Buffer
The AD844SQ/883 works as a high-speed sample-and-hold buffer when paired with a fast analog switch and hold capacitor at its inverting input. The current-feedback architecture minimizes the slewing limitations seen in unity-gain VFAs at hold-to-acquire steps, while the complementary-bipolar output delivers strong drive into the next-stage ADC. The combination of wide bandwidth, high slew rate, and MIL-STD-883 screening addresses fast data-acquisition front ends in radar and electronic-warfare receivers.
Recommended
Active Filter and High-Speed Integrator
The AD844SQ/883 is well suited to active filters (Sallen-Key, multiple-feedback, and state-variable) because the current-feedback topology keeps the loop gain high across the filter passband and preserves Q. Designers use it for 1 MHz to 10 MHz antialias filters ahead of high-speed IFMs, where the 2000 V/µs slew rate prevents slew-induced distortion on large transient inputs. The /883 screening allows deployment in MIL-spec filter assemblies without re-characterizing the filter for a different op amp.
Recommended
Military/Aerospace Signal Conditioning
The AD844SQ/883 is engineered specifically for MIL-STD-883 Class B high-reliability programs: military avionics, missile electronics, naval combat systems, and space-grade signal-conditioning modules. The hermetic CERDIP-8 package, burn-in screening, and traceable lot acceptance testing make it a defensible choice when a Certificate of Conformance is required. The combination of 60 MHz bandwidth, 2000 V/µs slew rate, and high DC precision lets one part cover multiple analog blocks per subsystem, reducing BOM diversity.
Recommended
Recommended Products Summary
Engineering reference data for AD844SQ/883 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD844SQ | AD844BQ | AD844AQ | AD844JR-16 |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | CERDIP-8 | CERDIP-8 - same | CERDIP-8 - same | CERDIP-8 - same | CERDIP-8 - same |
| Screening | MIL-STD-883 Class B (/883) | Standard (no /883) | Industrial grade | Industrial grade | Commercial (0 to +70 °C) |
| Operating Temperature Range | Military (per MIL-STD-883 Class B) | Military (per /883) | -40 °C to +85 °C | -40 °C to +85 °C | 0 °C to +70 °C |
| Topology | Current-feedback (CFA) | Current-feedback (CFA) - same | Current-feedback (CFA) - same | Current-feedback (CFA) - same | Current-feedback (CFA) - same |
| Bandwidth (G=+1) | 60 MHz | 60 MHz | 60 MHz | 60 MHz | 60 MHz |
| Slew Rate | 2000 V/µs | 2000 V/µs | 2000 V/µs | 2000 V/µs | 2000 V/µs |
| RoHS Status | Non-compliant (Sn/Pb CERDIP) | Non-compliant (Sn/Pb CERDIP) | Non-compliant (Sn/Pb CERDIP) | Non-compliant (Sn/Pb CERDIP) | Non-compliant (Sn/Pb CERDIP) |
Key Differentiators
- MIL-STD-883 Class B screened CFA in CERDIP-8 (vs AD844SQ)
- Hermetic CERDIP-8 package for sealed enclosures (vs AD844AQ)
- 60 MHz bandwidth preserved across gains (vs AD844JR-16)
Design Notes
Optimum small-signal bandwidth is achieved with a feedback resistor (Rf) of about 1 kΩ. Lowering Rf widens bandwidth but also reduces phase margin; raising Rf extends gain-bandwidth product but limits bandwidth and increases peaking. Place a 0.1 µF ceramic decoupling capacitor as close as possible to each supply pin (V+ pin 7 and V- pin 4), and add a larger tantalum or electrolytic bulk cap on the same node to handle large-signal transient currents. Estimated: with Rf = 1 kΩ, Rg = 1 kΩ, expected closed-loop bandwidth is approximately 60 MHz at gain +1.
The AD844 is a current-feedback amplifier: the inverting input (pin 2) is a low-impedance node whose bias current is appreciably larger than a precision voltage-feedback op amp. Always use a low-capacitance, low-leakage feedback resistor network and avoid large parasitic capacitance on the inverting node, which can cause peaking or oscillation. Keep the inverting-node trace short and route it away from noisy digital lines to preserve settling performance on large output steps.
The CERDIP-8 (Q) package has a thermal resistance theta-JA of approximately 90-100 °C/W (depending on socket and ambient). At typical quiescent current of about 7 mA per supply on ±15 V, internal dissipation is roughly 0.2 W, which is well within the package's rating. No heatsink is required under normal conditions; however, in confined sealed military enclosures, verify junction temperature against the MIL-STD-883 thermal derating curve rather than relying on the standard 25 °C ambient figure.
Do not treat the AD844 as a voltage-feedback op amp: capacitive loads on the output greater than a few tens of picofarads can destabilize a current-feedback amplifier unless a small series output resistor (typically 10-50 Ω) is added. Do not omit the feedback resistor - the inverting input MUST see a DC path to the output, otherwise the bias current will charge the parasitic capacitance and the output will rail. Do not use the AD844 for precision DC-amplified millivoltrails at gain +1 where DC offset drift over long missions is the dominant spec; use a precision VFA instead.
Compliance Information
MIL-STD-883 Class B screening per /883B suffix. CERDIP-8 package uses Sn/Pb lead finish per MIL-PRF-38535; not RoHS compliant. AEC-Q100 not applicable (this is a MIL-spec part, not automotive). REACH compliant per Analog Devices product page.
