Analog Devices Inc. AD571KD/+

Overview

AD571KD/+ 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 +4.5 V to +16.5 V V+ and –12 V to –16.5 V V–, delivers ±1/2 LSB relative accuracy at +25°C, supports unipolar (0 V to +10 V) and bipolar (–5 V to +5 V) input ranges, and achieves 15 μs minimum conversion time - used in precision data acquisition systems requiring self-contained, no-external-components A/D conversion.

For engineers reviewing the AD571KD/+ datasheet, AD571KD/+ pinout, AD571KD/+ application, or AD571KD/+ equivalent, key selection considerations include its 18-lead ceramic DIP package, bipolar/unipolar mode flexibility via open/shorted BIPOLAR OFFSET pin, 3-state digital outputs with DATA READY handshake, and compatibility with TTL/CMOS logic depending on V+ supply configuration.

Technical Context

The AD571KD/+ implements a current-mode successive-approximation architecture using an internal 10-bit current-output DAC and I²L SAR logic, where input current through a laser-trimmed 5 kΩ thin-film resistor is balanced against DAC output current. Its comparator determines bit states MSB-to-LSB, and the SAR latches the final code upon completion.

Conversion is initiated by a low-going BLANK AND CONVERT (B&C) signal; DATA READY (active-low, open-collector) asserts within 40 μs max to indicate valid 10-bit parallel output. The device features separate analog common (ACOM) and digital common (DCOM) pins, supporting up to ±200 mV common-mode offset between them, and includes a dedicated BIPOLAR OFFSET control pin that injects precise MSB–½LSB current into the comparator summing node for bipolar range operation.

Key Specifications

Pinout & Package

AD571KD/+ is housed in an 18-lead side-brazed ceramic dual in-line package (SBDIP), designated D-18 per Analog Devices' ordering guide. Pin spacing is 0.100" (2.54 mm) BSC, with overall body dimensions 0.960" × 0.290" (24.38 mm × 7.37 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD571KD/+, AD573JD offers higher resolution at the expense of speed and bipolar capability, while MAX160BCNG+ trades integrated simplicity for surface-mount compatibility and external component dependency - making AD571KD/+ optimal for rugged, low-component-count, bipolar-capable designs.

Availability

AD571KD/+ is available at Aetrix Electronics and suitable for industrial process monitoring, aerospace sensor conditioning, and test & measurement equipment requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for AD571KD/+ 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing ICs for precision instrumentation, industrial, and aerospace applications.

The AD571KD/+ belongs to Analog Devices' legacy high-accuracy monolithic ADC product line, designed specifically for applications demanding self-contained, no-external-components digitization with guaranteed linearity and temperature-stable reference performance.

FAQ

What is the operating temperature range for the AD571KD/+?

The AD571KD/+ is rated for operation from 0°C to +70°C, as specified in the Analog Devices ordering guide. This commercial-grade temperature range distinguishes it from the AD571JD (same range, lower accuracy grade) and AD571SD (–55°C to +125°C, military-grade). All electrical specifications in the datasheet - including ±1/2 LSB relative accuracy and 15–40 μs conversion time - are guaranteed across this 0°C to +70°C span.

Does the AD571KD/+ require an external reference voltage?

No, the AD571KD/+ does not require an external reference voltage. It integrates a temperature-compensated buried Zener reference that serves as the primary voltage reference for the internal DAC and guarantees excellent stability over time and temperature. This internal reference eliminates the need for external precision references, simplifying system design and reducing component count - a defining feature of the AD571KD/+ architecture.

How is bipolar input range enabled on the AD571KD/+?

Bipolar input range (–5 V to +5 V) on the AD571KD/+ is enabled by leaving the BIPOLAR OFFSET pin (Pin 11) unconnected (open). When open, the device injects a precise offset current equal to MSB–½LSB into the comparator summing node, shifting the transfer function to center at 0 V. In contrast, shorting Pin 11 to DIGITAL COM selects unipolar mode (0 V to +10 V). No external components are needed to switch between modes.

What logic families is the AD571KD/+ compatible with?

AD571KD/+ supports both TTL and CMOS logic interfaces depending on V+ supply voltage: at +4.5 V to +5.5 V, it meets TTL input thresholds (Logic "1" ≥2.0 V, Logic "0" ≤0.8 V); at +4.5 V to +16.5 V, it interfaces directly with CMOS logic. Output drivers provide 3.2 mA sink and 0.5 mA source capability, ensuring robust drive into standard logic loads without external buffers.

Can multiple AD571KD/+ devices share a common data bus?

Yes, multiple AD571KD/+ devices can share a common data bus using multiplex mode. Each device's 10-bit outputs are 3-state; driving BLANK AND CONVERT (Pin 9) high disables outputs, allowing one AD571KD/+ to drive the bus while others remain high-impedance. DATA READY outputs can be wire-OR'd with pull-up resistors to generate a shared status signal indicating when the selected device has completed conversion.