Analog Devices Inc. AD1674BD

Overview

AD1674BD from Analog Devices is a complete monolithic 12-bit, 100 kSPS analog-to-digital converter with integrated sample-and-hold amplifier (SHA), on-chip ±10 V reference, and three-state parallel digital interface. It supports unipolar (0 V–10 V, 0 V–20 V) and bipolar (±5 V, ±10 V) input ranges, operates on ±12 V/±15 V analog and +5 V logic supplies, and delivers ±1/2 LSB integral nonlinearity at –40°C to +85°C. It is used in precision data acquisition systems requiring stable DC accuracy and verified AC performance.

For engineers reviewing the AD1674BD datasheet, AD1674BD pinout, AD1674BD application, or AD1674BD equivalent, this page provides confirmed technical identity, validated 28-pin ceramic DIP package mapping, full pin function table, real-world timing and linearity specs, and two verified alternative parts with documented functional and thermal differences.

Technical Context

The AD1674BD implements a successive approximation register (SAR) architecture with an integrated SHA that supports full Nyquist bandwidth operation up to 500 kHz linear bandwidth and 1 MHz full-power bandwidth. Its BiMOS II process integrates high-precision bipolar analog circuitry-including laser-trimmed scaling and offset resistors-with CMOS digital logic for guaranteed DC and AC specifications.

It features dual-mode digital interface: full-control mode using CE, CS, R/C, A0, and 12/8 pins for multiplexed bus systems, and stand-alone mode using only R/C for dedicated channel applications. Conversion timing is deterministic-9 µs for 12-bit, 7 µs for 8-bit-with STS output indicating conversion status and automatic hold-to-sample transition after completion.

Key Specifications

Pinout & Package

AD1674BD is housed in a 28-lead hermetically sealed ceramic DIP (package code D-28), rated for industrial temperature operation and compatible with MIL-STD-883 screening. The package provides robust moisture resistance and thermal stability for long-term deployment in harsh environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD1674BR, AD1674BD offers superior moisture resistance and thermal cycling endurance in hermetic ceramic packaging, while AD7892BR-1 trades integration for reduced footprint and power-making it suitable only when external reference and driver resources are available and serial interface simplifies routing.

Availability

AD1674BD is available at Aetrix Electronics and suitable for industrial process monitoring, automotive ECU subsystems, avionics signal conditioning, and test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD1674BD 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 industrial, automotive, communications, and defense markets since 1965.

The AD1674 product line was designed as a drop-in upgrade to AD574A/AD674A for applications demanding integrated sample-and-hold, guaranteed AC performance, and multi-range flexibility without external support components.

FAQ

What is the maximum sampling rate supported by the AD1674BD?

The AD1674BD supports a maximum sampling rate of 100 kSPS, with guaranteed 12-bit performance across its full operating temperature range of –40°C to +85°C. This rate corresponds to a minimum conversion time of 9 µs for 12-bit cycles and 7 µs for 8-bit cycles, as specified in the switching timing tables for the B-grade device. The AD1674BD maintains this rate without performance degradation under worst-case supply and temperature conditions.

Does the AD1674BD require external calibration components?

No, the AD1674BD does not require external calibration components for standard operation. It includes factory-laser-trimmed scaling and bipolar offset resistors, an internal 10 V reference, and integrated sample-and-hold amplifier-enabling direct use of all four input ranges (±5 V, ±10 V, 0–10 V, 0–20 V) without external resistors or references. Only the BIP OFF pin requires a 50 Ω resistor to REF OUT for bipolar mode, which is a fixed-value component included in typical application schematics.

How does the AD1674BD handle bipolar versus unipolar input configurations?

The AD1674BD selects input configuration via the BIP OFF pin: connecting it to REF OUT through a 50 Ω resistor enables ±5 V or ±10 V bipolar operation, while tying it to AGND enables 0–10 V or 0–20 V unipolar operation. The 10 VIN and 20 VIN pins are dedicated analog inputs-only one is used per configuration, with the other left unconnected. Internal scaling resistors automatically adjust gain to maintain 1 mA full-scale DAC current across both spans.

Can the AD1674BD interface directly with an 8-bit microprocessor bus?

Yes, the AD1674BD supports direct 8-bit microprocessor interface via its configurable digital output mode. When the 12/8 pin is held LOW, the device outputs two 8-bit words: A0 = LOW enables DB4–DB11 (upper byte), and A0 = HIGH enables DB0–DB3 with DB7–DB4 forced to zero (lower byte with zero-padding). This eliminates need for external latches or bus transceivers when interfacing with Z80, 8051, or similar 8-bit architectures.

What is the purpose of the STS pin on the AD1674BD?

The STS (Status) pin on the AD1674BD is a digital output that goes HIGH at conversion start and returns LOW when conversion completes and output data is valid. It provides hardware handshaking for interrupt-driven acquisition, allowing microprocessors to initiate reads only when data is ready-eliminating polling delays and ensuring deterministic timing in real-time control loops. STS delay from R/C is 200 ns, and its LOW-to-valid timing is guaranteed across all temperature grades.