Analog Devices Inc. AD574AJNZ

Overview

AD574AJNZ from Analog Devices is a monolithic 12-bit successive-approximation analog-to-digital converter (ADC) with on-chip reference, clock, and three-state data output buffers. It delivers ±1 LSB linearity error over 0°C to +70°C, supports unipolar (0 V to +10 V or 0 V to +20 V) and bipolar (±5 V or ±10 V) input ranges, and achieves ≤35 µs full-scale conversion time. It is used in precision data acquisition systems requiring self-contained, calibrated ADC functionality without external DAC or timing components.

For engineers reviewing the AD574AJNZ datasheet, AD574AJNZ pinout, AD574AJNZ application, or AD574AJNZ equivalent, this page provides verified technical context, validated pin functions, confirmed operating conditions (±12 V/±15 V analog supplies, +5 V logic), and real-world interface constraints - including mandatory 12/8 pin hard-wiring and analog input drive requirements for 12-bit accuracy.

Technical Context

The AD574AJNZ implements a fully integrated successive-approximation architecture with an internal 12-bit current-output DAC, temperature-compensated buried Zener reference (10.00 V ±0.2%), and comparator-based bit decision logic. Its SAR sequencer drives DAC bits MSB-to-LSB while dynamically balancing input current through trimmed thin-film scaling resistors (5 kΩ for 10 V span, 10 kΩ for 20 V span).

Control logic interprets CE/CS/R/C/A0/12/8 signals to initiate 8-bit or 12-bit conversions and enable parallel data readout in either 12-bit word or two 8-bit nibble modes. The STS output asserts high during conversion and returns low upon completion, preventing bus contention by disabling outputs until conversion finishes.

Key Specifications

Pinout & Package

AD574AJNZ is supplied in a 28-pin plastic DIP (N-28) package with 0.6-inch width and standard through-hole footprint. Pin numbering follows dual-in-line convention with Pin 1 at top-left corner (notch side).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD574AJNZ, AD7874KNZ trades parallel simplicity and integrated reference for higher speed and serial efficiency, while MAX195BCNG+ delivers superior resolution and linearity at the cost of interface complexity and loss of direct bus compatibility.

Availability

AD574AJNZ is available at Aetrix Electronics and suitable for industrial process monitoring, test & measurement equipment, avionics sensor interfaces, and medical diagnostic signal acquisition requiring stable component supply and long-term obsolescence management.

Supply support for AD574AJNZ 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, founded in 1965 and headquartered in Wilmington, MA.

The AD574A family was designed as a complete, single-chip 12-bit ADC solution for industrial and instrumentation applications where reliability, calibrated accuracy, and minimal external component count were critical design requirements.

FAQ

What is the guaranteed linearity performance of the AD574AJNZ over its operating temperature range?

The AD574AJNZ guarantees ±1 LSB maximum linearity error from 0°C to +70°C. This specification defines the peak deviation of any output code from the ideal straight-line transfer function, ensuring that measurements remain within 0.024% of full scale across the entire industrial temperature range. The AD574AJNZ achieves this without user calibration, relying on factory-trimmed thin-film resistors and a compensated Zener reference.

Can the AD574AJNZ operate with ±12 V analog supplies instead of ±15 V?

Yes, the AD574AJNZ supports VCC = +11.4 V to +16.5 V and VEE = –11.4 V to –16.5 V, making ±12 V fully compliant. However, the internal reference output current drops to <1.5 mA under ±12 V, and external buffering is recommended if driving loads beyond the reference input resistor (0.5 mA) and bipolar offset resistor (1 mA). The AD574AJNZ datasheet explicitly validates operation at ±12 V with adjusted power supply rejection specs.

How does the AD574AJNZ handle analog input drive requirements for 12-bit accuracy?

The AD574AJNZ demands a low-impedance analog source due to dynamic current modulation at its input node during conversion. Driving op amps must sustain loop gain ≥60 dB at 500 kHz and settle within 1 µs after each of the 12 internal bit tests. The AD574AJNZ datasheet recommends AD585 (SHA), AD711, or AD544 op amps - and warns that inadequate drive causes missing codes or increased differential nonlinearity beyond the guaranteed ±1 LSB.

What is the function of the 12/8 pin on the AD574AJNZ, and how must it be connected?

The 12/8 pin on the AD574AJNZ selects data output format: tied to VLOGIC for 12-bit parallel word output, or tied to DIGITAL COMMON for two 8-bit nibble reads. It is explicitly stated as non-TTL-compatible and must be hard-wired - not driven by logic gates or microcontroller pins. Incorrect connection (e.g., floating or actively driven) violates the AD574AJNZ absolute maximum ratings and risks latch-up or output corruption.

Does the AD574AJNZ require external components for basic operation, and what are the minimum connections?

No, the AD574AJNZ requires zero external components for basic 12-bit conversion. Minimum connections are: VCC (+12 V/+15 V), VEE (–12 V/–15 V), VLOGIC (+5 V), analog input (e.g., Pin 14 to Pin 9), digital ground (Pin 15), analog ground (Pin 9), and control signals (CE, CS, R/C, A0). REF OUT (Pin 8) may connect directly to REF IN (Pin 10) via a 50 Ω resistor for full-scale trim - but even this is optional for many applications given the AD574AJNZ's factory-calibrated accuracy.