Analog Devices Inc. AD574AKE

Overview

AD574AKE from Analog Devices is a monolithic 12-bit successive-approximation analog-to-digital converter (ADC) with on-chip reference, internal clock, and three-state parallel digital outputs. It delivers ±1/2 LSB linearity error over 0°C to +70°C, supports ±5 V, ±10 V, 0–10 V, and 0–20 V input ranges, and achieves 35 µs max 12-bit conversion time - used in precision data acquisition systems requiring high DC accuracy and minimal external components.

For engineers reviewing the AD574AKE datasheet, AD574AKE pinout, AD574AKE application, or AD574AKE equivalent, this page provides verified technical context, confirmed pin functions, real-world interface constraints (e.g., 12/8 pin hard-wiring requirement), and validated alternatives for industrial instrumentation, test equipment, and embedded control systems where guaranteed no-missing-codes 12-bit resolution is mandatory.

Technical Context

The AD574AKE implements a fully self-contained 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-testing logic. Its SAR sequencer drives the DAC from 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 decodes CE/CS/R/C/A0/12/8 signals to initiate 8-bit or 12-bit conversions and enable 12-bit parallel output or byte-mode reads (MSB nibble or LSB+zeros). The STS pin provides end-of-conversion status, and all digital I/O meets standard TTL voltage thresholds except the 12/8 input, which must be hard-wired to VLOGIC or Digital Common.

Key Specifications

Pinout & Package

LCC (E-28A) ceramic leadless chip carrier package - 28-terminal surface-mount device with leads arranged in a 2-row J-bend configuration; requires controlled reflow profile and ground-plane thermal relief per Analog Devices AN-287.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7874KN and MAX197ACPP, the AD574AKE uniquely combines guaranteed ±1/2 LSB linearity, on-chip 10 V reference, bipolar/unipolar input flexibility, and ceramic LCC ruggedness - making it irreplaceable in legacy industrial and aerospace systems where long-term calibration stability and minimal component count are non-negotiable.

Availability

AD574AKE is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, avionics sensor interfaces, and medical diagnostic instrumentation requiring stable component supply and long-lifecycle support.

Supply support for AD574AKE 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 engineered for high-accuracy, self-contained data acquisition in harsh environments - targeting applications where external component count, long-term drift, and guaranteed monotonicity outweigh raw speed requirements.

FAQ

What is the maximum operating temperature range for the AD574AKE?

The AD574AKE is rated for operation from 0°C to +70°C. This grade (K) guarantees ±1/2 LSB linearity error and no missing codes across that full industrial temperature range. It is distinct from the AD574AS/AT/AU military grades, which operate from –55°C to +125°C but use different package options like ceramic DIP (D-28).

Does the AD574AKE require an external clock source?

No, the AD574AKE does not require an external clock source. It contains a fully integrated internal clock circuit necessary for its successive-approximation conversion process. No external timing components are needed - the device begins conversion immediately upon assertion of the CE and R/C control signals.

Can the AD574AKE interface directly to an 8-bit microcontroller bus?

Yes, the AD574AKE supports direct 8-bit bus interfacing via its configurable 12/8 and A0 pins. When 12/8 is tied to Digital Common, the device outputs two 8-bit bytes: A0 = 0 enables the 8 MSBs (DB11–DB4), and A0 = 1 enables the 4 LSBs followed by four trailing zeroes (DB3–DB0, 0, 0, 0, 0), enabling seamless connection without external latches or buffers.

What is the purpose of the 12/8 pin on the AD574AKE, and how must it be connected?

The 12/8 pin selects data output format: tied to VLOGIC for 12-bit parallel word output, or tied to Digital Common for two 8-bit byte outputs. Critically, it is not TTL-compatible and must be hard-wired - never driven by logic gates or microcontroller pins - to prevent undefined behavior or damage due to voltage level mismatch.

How is the internal reference of the AD574AKE used, and what are its limitations?

The AD574AKE's internal 10.00 V ±0.2% reference is used for DAC scaling and can supply up to 1.5 mA to external loads. However, the load must remain constant during conversion; any variation causes full-scale error. For ±12 V supplies or variable external loading, Analog Devices recommends buffering the REF OUT with an op amp such as the AD708.