Analog Devices Inc. AD679KN

Overview

AD679KN from Analog Devices is a complete 14-bit, 128 kSPS monolithic sampling ADC integrating sample-and-hold amplifier (SHA), internal 5 V reference, clock generator, and 8-bit bus interface in a 28-lead plastic DIP package. It delivers 78 dB S/N+D (K-grade), 1 MHz full-power bandwidth, and 10 MΩ input impedance for direct connection to unbuffered sources. Used in precision data acquisition systems requiring high-resolution DC accuracy and dynamic performance.

For engineers reviewing the AD679KN datasheet, AD679KN pinout, AD679KN application, or AD679KN equivalent, key selection criteria include its bipolar/unipolar dual-mode operation, two-read 14-bit output format, factory-trimmed DC accuracy (±0.07% FSR gain error, ±0.08% FSR zero error), MIL-STD-883-compliant variants, and pin compatibility with AD678 for system upgrades.

Technical Context

The AD679KN employs a recursive subranging architecture with flash converter circuitry and on-chip error correction to achieve 14-bit resolution at 128 kSPS. Its SHA supports 1.5 µs input settling time and 150 ps aperture jitter, enabling accurate sampling of signals up to 500 kHz full-linear bandwidth.

It operates from +5 V (VDD), ±12 V (VCC/VEE) supplies, dissipating 560 mW typical. The device features TTL/CMOS-compatible digital I/O, three-state outputs, and configurable synchronous/asynchronous conversion control via SYNC, CS, SC, and EOCEN pins.

Key Specifications

Pinout & Package

AD679KN is housed in a 28-lead plastic DIP (N-28) package with 0.6-inch width and standard through-hole footprint. Pin 1 identifier located at top-left corner; pins 12 and 14 are tied to DGND; pin 16 is internally unused and must be connected to DGND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-resolution sampling ADC applications.

Compared with AD678KN and ADS8505IPW, the AD679KN uniquely balances 14-bit DC accuracy, integrated analog front-end, and legacy bus compatibility - making it optimal for upgrading existing 12-bit systems without layout changes while meeting tighter linearity requirements.

Availability

AD679KN is available at Aetrix Electronics and suitable for industrial process monitoring, test & measurement equipment, medical diagnostic instrumentation, aerospace data acquisition, and precision calibration systems requiring stable component supply across extended product lifecycles.

Supply support for AD679KN 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, founded in 1965 and headquartered in Norwood, MA.

The AD679KN belongs to Analog Devices' precision data acquisition IC family, engineered for applications demanding simultaneous high DC accuracy and dynamic performance - especially in legacy industrial and military systems where integration, reliability, and long-term supply stability are critical.

FAQ

What is the operating temperature range for the AD679KN?

The AD679KN is rated for 0°C to +70°C operation (J/K grade). This range is validated across all AC and DC specifications, including ±0.11% FSR gain error and 78 dB S/N+D ratio. The part uses Analog Devices' BiMOS process to maintain stability within this commercial temperature window, and thermal drift parameters (e.g., 0.04% FSR/°C unipolar zero drift) are guaranteed across the full span.

Does the AD679KN require external calibration components?

The AD679KN is factory-trimmed for offset, gain, and linearity, so no external calibration is required to meet datasheet specifications. In unipolar mode, only a single 50 Ω 1% resistor is needed; bipolar mode adds one more trim resistor. If system accuracy tolerances allow ±0.08% FSR zero error and ±0.11% FSR gain error, even those resistors may be omitted - confirmed by AD679KN test data showing typical performance within limits without user adjustment.

How does the AD679KN handle analog input signal conditioning?

The AD679KN integrates a high-impedance (10 MΩ) sample-and-hold amplifier with 1.5 µs settling time and 150 ps aperture jitter, allowing direct connection to unbuffered sources or multiplexer outputs with ≤300 Ω channel mismatch. Its 10 V p-p full-scale range accepts most sensor outputs without attenuators, and the internal 5 V reference eliminates external reference drift - all verified in AD679KN characterization across 0°C to +70°C.

Can the AD679KN interface with an 8-bit microprocessor bus?

Yes - the AD679KN delivers its 14-bit result in two 8-bit reads (high byte first, then low byte) using HBE, OE, and CS controls. DB7–DB0 are TTL/CMOS-compatible three-state outputs, and timing parameters (e.g., tBA = 10 ns access time, tRP = 195 ns read pulse width) are specified for 8-bit bus loading (COUT = 100 pF). This architecture is explicitly designed for seamless integration with legacy 8-bit systems like Intel 8085 or Zilog Z80 platforms.

What are the power supply requirements for the AD679KN?

The AD679KN requires three independent supplies: +5 V (VDD, 8–12 mA), +12 V (VCC, 18–20 mA), and –12 V (VEE, 25–34 mA), totaling 560 mW typical power dissipation. Power supply rejection is guaranteed at ±6 LSB for ±5% variation on each rail. Decoupling is critical: 10 µF tantalum on REFIN–AGND improves S/N+D, and separate analog/digital ground planes (AGND/DGND) are mandatory per AD679KN layout guidelines to maintain 78 dB performance.