Analog Devices Inc. AD674BKN

Overview

AD674BKN from Analog Devices is a complete monolithic 12-bit successive-approximation analog-to-digital converter (ADC) with integrated voltage reference, clock, and three-state digital output buffers. It supports 0 V–10 V, 0 V–20 V, ±5 V, and ±10 V input ranges; operates on +5 V logic, ±12 V/±15 V analog supplies; and delivers ≤15 µs max conversion time with ±1/2 LSB integral nonlinearity over 0°C to +70°C. It is used in precision data acquisition systems requiring direct microprocessor bus interfacing.

For engineers reviewing the AD674BKN datasheet, AD674BKN pinout, AD674BKN application, or AD674BKN equivalent, key selection considerations include its industry-standard AD574A-compatible 28-pin DIP package, dual-mode 8-/12-bit parallel data output, internal 10.00 V ±1% reference, bipolar/unipolar range flexibility, and guaranteed no missing codes across temperature.

Technical Context

The AD674BKN implements a SAR architecture with an on-chip 12-bit current-output DAC, comparator, and laser-trimmed thin-film resistor network for scaling and bipolar offset. Its internal 10 V reference exhibits 10 ppm/°C typical drift and supplies up to 2.0 mA externally while maintaining stability during conversion.

Control logic supports full-control mode (CS, CE, R/C, A0, 12/8) and standalone mode (R/C edge-triggered), enabling both 8-bit short-cycle and full 12-bit conversions. Output buffering is three-state, configurable for byte- or word-wide reads, with timing validated for 8-bit and 16-bit microprocessor buses.

Key Specifications

Pinout & Package

AD674BKN is housed in a 28-lead plastic DIP (N-28) package with 0.6-inch body width and standard through-hole footprint compatible with AD574A layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit ADC applications.

Compared with AD674BJN, AD674BKN provides tighter ±1/2 LSB linearity for higher-accuracy applications without added calibration effort; compared with AD7819ARZ, it offers AD574A-compatible parallel interface, integrated 10 V reference, and bipolar range support-reducing design complexity in legacy industrial and test equipment upgrades.

Availability

AD674BKN is available at Aetrix Electronics and suitable for industrial process monitoring, test & measurement equipment, avionics sensor interface, and medical diagnostic instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for AD674BKN 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD674BKN belongs to Analog Devices' legacy precision ADC product line, designed specifically for drop-in upgrades of AD574A-based systems requiring improved speed, lower power, and enhanced temperature stability in industrial and aerospace data acquisition.

FAQ

What is the maximum conversion time specified for the AD674BKN?

The AD674BKN has a maximum conversion time of 15 µs for a full 12-bit cycle, as confirmed in the Ordering Guide and CONVERTER START TIMING table. This applies across its rated 0°C to +70°C temperature range and is guaranteed for all units at final electrical test. The 15 µs figure represents worst-case timing under conditions including VCC = +15 V ±10%, VEE = –15 V ±10%, and VLOGIC = +5 V ±10%. AD674BKN achieves this performance while maintaining ±1/2 LSB integral nonlinearity.

Does the AD674BKN require external calibration components for standard operation?

No, the AD674BKN does not require external calibration components for standard operation. Its laser-trimmed thin-film resistors provide factory-calibrated scaling and bipolar offset, supporting 0 V–10 V, 0 V–20 V, ±5 V, and ±10 V input ranges out-of-the-box. The internal 10.00 V ±1% reference is also trimmed and stable. Only optional trims (e.g., R1/R2 in Figure 7) are needed if system-level accuracy exceeds the AD674BKN's guaranteed ±1/2 LSB INL or ±0.1% full-scale calibration error.

Can the AD674BKN operate with a single +5 V supply?

No, the AD674BKN cannot operate with a single +5 V supply. It requires three independent supplies: +5 V (VLOGIC, Pin 1), +12 V or +15 V (VCC, Pin 7), and –12 V or –15 V (VEE, Pin 11). These are mandatory for proper operation of its internal SAR, DAC, comparator, and reference circuitry. Attempting to power VCC or VEE from +5 V will result in functional failure, undefined output, or permanent damage per Absolute Maximum Ratings.

Is the AD674BKN pin-compatible with the AD574A?

Yes, the AD674BKN is fully pin-compatible with the industry-standard AD574A in its 28-lead plastic DIP package (N-28). All 28 pins match functionally and physically, including identical placement of VLOGIC, CS, R/C, CE, REF OUT, REF IN, AGND, DGND, and DB0–DB11. This allows direct replacement in existing AD574A designs, delivering faster 15 µs conversion (vs. 35 µs), lower power consumption, and improved linearity without any PCB changes.

What input impedance does the AD674BKN present to a 10 V span signal?

The AD674BKN presents a nominal input impedance of 5 kΩ to a 10 V span signal applied at Pin 13 (10 VIN) with respect to AGND (Pin 9). This value is specified in the ANALOG INPUT section of the datasheet and remains stable across temperature and supply variations. For 20 V span signals applied at Pin 14 (20 VIN), the input impedance is 10 kΩ. These impedances are fixed by internal thin-film resistor networks and do not vary with conversion state.