Analog Devices Inc. AD684SQ/883B

Overview

AD684SQ/883B from Analog Devices is a monolithic quad sample-and-hold amplifier (SHA) designed for high-accuracy, multichannel data acquisition systems operating across –55°C to +125°C. It delivers 1 µs acquisition time to 0.01%, 75 ps aperture jitter, 0.01 µV/µs droop rate, and independent control per channel - enabling simultaneous sampling of four analog signals before feeding 12- to 14-bit ADCs such as AD7672.

For engineers reviewing the AD684SQ/883B datasheet, AD684SQ/883B pinout, AD684SQ/883B application, or AD684SQ/883B equivalent, key selection criteria include MIL-STD-883B compliance, interchannel matching (≤300 ps aperture offset), hold-mode noise (125 µV rms), and self-correcting architecture that minimizes gain/offset error without external trimming.

Technical Context

The AD684SQ/883B implements a BiMOS-based self-correcting SHA architecture that reconfigures internal circuitry post-hold command to compensate for charge injection, amplifier offset, and gain errors - ensuring accuracy in hold mode while decoupling sample-mode fidelity. Each channel integrates its own hold capacitor and operates with independent digital control inputs.

It supports ±10.8 V to ±13.2 V dual supplies, delivers ±5 mA output drive into low-impedance loads (0.3 Ω typical), and maintains 80 dB interchannel isolation at 100 kHz. Its 4 MHz small-signal bandwidth and 1 MHz full-power bandwidth enable accurate sampling of fast-rising transients within its ±5 V input range.

Key Specifications

Pinout & Package

AD684SQ/883B is housed in a hermetically sealed 16-pin Cerdip (Q-16) package compliant with MIL-STD-883B screening requirements. The package features 0.3" width, ceramic body, and gold-plated leads suitable for high-reliability military/aerospace applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad sample-and-hold amplifier applications.

Compared with AD684SQ (non-883B), AD684SQ/883B adds verified hermetic packaging, lot traceability, and accelerated life testing - critical for aerospace deployment. Against HT0804S, it delivers 2.5× faster acquisition, 2.7× lower jitter, and eliminates four external hold capacitors, reducing layout complexity and thermal drift sources.

Availability

AD684SQ/883B is available at Aetrix Electronics and suitable for radar pulse capture systems, avionics sensor fusion units, electronic warfare signal intelligence platforms, and high-energy physics detector readout systems requiring stable component supply under extended temperature and reliability constraints.

Supply support for AD684SQ/883B includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, aerospace, and industrial markets since 1965.

The AD684 product line delivers monolithic, multi-channel sample-and-hold amplifiers optimized for military-grade data acquisition - emphasizing timing coherence, interchannel matching, and operation across extreme temperature ranges.

FAQ

What is the operating temperature range for AD684SQ/883B?

The AD684SQ/883B is specified for continuous operation from –55°C to +125°C, with full parametric performance guaranteed across this range per MIL-STD-883B test conditions. This includes validated acquisition time, droop rate, and interchannel matching at both temperature extremes - making AD684SQ/883B suitable for airborne, space, and downhole applications where ambient thermal stress exceeds commercial limits.

Does AD684SQ/883B require external hold capacitors?

No, AD684SQ/883B integrates precision hold capacitors on-die for all four channels, eliminating the need for external components. This monolithic implementation ensures consistent capacitance value, temperature coefficient, and charge retention characteristics across channels - directly contributing to the device's <300 ps interchannel aperture offset and <0.01 µV/µs droop rate without user trimming or layout-dependent tuning.

How does the self-correcting architecture of AD684SQ/883B improve accuracy?

The self-correcting architecture in AD684SQ/883B actively compensates for charge injection, amplifier offset, and gain errors after the hold command is issued - reconfiguring internal circuitry to produce an accurately held output. This results in hold-mode offset stability of <±3 mV and <10 µV/°C drift, enabling high-precision DC measurements without external nulling circuits or per-channel calibration routines.

Can AD684SQ/883B drive ADCs directly without buffer amplifiers?

Yes, AD684SQ/883B can directly drive high-speed 12- to 14-bit ADCs such as the AD7672 due to its 0.3 Ω typical output resistance, ±5 mA drive capability, and 500 ns hold settling time to 1 mV. Its low output impedance and fast settling eliminate the need for intermediate op-amps in most designs - reducing signal path latency, component count, and potential noise sources in time-critical DAQ systems.

What is the significance of the 75 ps aperture jitter specification for AD684SQ/883B?

The 75 ps maximum aperture jitter in AD684SQ/883B defines the temporal uncertainty in sampling instant - directly limiting achievable SNR at high input frequencies. At 100 kHz, this jitter contributes <0.5 dB SNR degradation, preserving effective resolution for FFT-based spectral analysis and communication signal demodulation where phase coherence across channels is mission-critical.