Analog Devices Inc. AD571JD

Overview

AD571JD from Analog Devices is a complete 10-bit monolithic successive-approximation analog-to-digital converter (ADC) with internal DAC, comparator, SAR register, and temperature-compensated buried Zener reference. It operates from +5 V and –15 V supplies, delivers ±1/2 LSB relative accuracy over 0°C to +70°C, supports unipolar (0 V to +10 V) and bipolar (–5 V to +5 V) input ranges, and achieves 25 μs typical conversion time - used in precision data acquisition systems for industrial instrumentation and test equipment.

For engineers reviewing the AD571JD datasheet, AD571JD pinout, AD571JD application, or AD571JD equivalent, this page provides verified technical context, validated pin functions, confirmed operating parameters, real-world interface constraints, and two field-tested alternative parts for design continuity and sourcing flexibility.

Technical Context

The AD571JD implements a fully integrated I²L-based successive-approximation architecture with a 10-bit current-output DAC, laser-trimmed 5 kΩ thin-film input resistor, and on-chip comparator referenced to a temperature-stable buried Zener. Its SAR logic sequences MSB-to-LSB to balance input current against DAC output current through the summing node.

It features dual common terminals (digital common and analog common), separate bipolar offset control (pin 18), open-collector DATA READY (pin 17), and three-state digital outputs with active pull-ups. The device requires no external clock or timing components and supports both Convert Pulse and Multiplex control modes via the BLANK AND CONV (pin 3) line.

Key Specifications

Pinout & Package

AD571JD is housed in an 18-lead side-brazed ceramic dual in-line package (SBDIP, D-18), hermetically sealed for high-reliability industrial and military applications. Pin spacing is 0.100" (2.54 mm), with 0.310" × 0.220" body dimensions and 0.098" max lead height.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit successive-approximation ADC applications.

Compared with AD571JD, AD7572A offers higher resolution but demands external components for reference and bipolar operation, while MAX160 trades bipolar support and robustness for speed and single-supply simplicity - AD571JD remains optimal where integrated Zener reference, dual-supply operation, and field-proven reliability in harsh environments are critical.

Availability

AD571JD is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, avionics sensor interfaces, and calibration laboratory standards requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for AD571JD 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 AD571JD belongs to Analog Devices' legacy precision ADC family designed for high-accuracy, low-drift, single-chip data acquisition in industrial, aerospace, and metrology applications where integration, stability, and long-term reliability are non-negotiable.

FAQ

What is the guaranteed operating temperature range for the AD571JD?

The AD571JD is specified for operation from 0°C to +70°C. This commercial-grade temperature range is explicitly defined in the Ordering Guide and confirmed in the Specifications table under "TEMPERATURE RANGE" for the AD571J model. The device undergoes full electrical testing across this range, and all min/max parameters - including relative accuracy, conversion time, and power supply rejection - are guaranteed within these limits. No derating is required at the endpoints.

Does the AD571JD require an external clock or timing controller?

No, the AD571JD does not require an external clock. Its successive-approximation conversion is internally timed using the I²L logic propagation delays and comparator response. The only required control signal is the BLANK AND CONV (pin 3) line: a low pulse initiates conversion, and DATA READY (pin 17) asserts low upon completion. This self-contained timing eliminates clock jitter concerns and simplifies interface to microprocessors or FPGA controllers.

How is bipolar input range enabled on the AD571JD?

Bipolar input range (–5 V to +5 V) is enabled by leaving pin 10 (BIPOLAR OFF) unconnected (open). When open, the internal bipolar offset current is injected into the comparator summing node, shifting the transfer function. Shorting pin 10 to DIGITAL COM selects unipolar mode (0 V to +10 V). No external components are needed - the mode is purely determined by the presence or absence of that connection, as confirmed in the Circuit Description and Figure 4.

Can the AD571JD interface directly to a 5 V TTL microprocessor bus?

Yes, the AD571JD is fully compatible with 5 V TTL logic. Its logic "1" threshold is 2.0 V minimum (tested), logic "0" is 0.8 V maximum, and output sink/source currents (3.2 mA / 0.5 mA) meet TTL drive requirements. The three-state outputs and open-collector DATA READY support direct connection to shared 8-bit or 16-bit buses, as demonstrated in Figure 14 and the Interfacing section - no level-shifting buffers are necessary.

What is the purpose of the separate ANALOG COM and DIGITAL COM pins on the AD571JD?

The separate ANALOG COM (pin 8) and DIGITAL COM (pin 9) pins isolate analog signal return paths from digital ground noise. ANALOG COM carries up to 2 mA of transient and static current during conversion, while DIGITAL COM serves as the logic reference. The datasheet specifies ≤200 mV allowable common-mode voltage between them - this separation prevents digital switching noise from modulating the analog input offset, preserving the ±1/2 LSB accuracy in real-world PCB layouts.