Analog Devices Inc. AD774BARZ

Overview

AD774BARZ from Analog Devices is a complete monolithic 12-bit successive-approximation analog-to-digital converter with on-chip 10 V reference, clock, and three-state output buffers. It supports 0 V–10 V, 0 V–20 V, ±5 V, and ±10 V input ranges; achieves 8 µs max conversion time; operates from +5 V logic, ±12 V/±15 V analog supplies; and targets precision data acquisition in industrial control and test equipment.

For engineers reviewing the AD774BARZ datasheet, AD774BARZ pinout, AD774BARZ application, or AD774BARZ equivalent, this page delivers verified technical context, exact pin functions, calibrated input range behavior, timing-critical interface guidance, and validated drop-in alternatives for legacy AD574A-based systems.

Technical Context

The AD774BARZ implements a SAR architecture with internal 12-bit current-output DAC, laser-trimmed thin-film resistors for scaling and bipolar offset, and a temperature-compensated 10.00 V ±1% reference. Its control logic supports full-control mode (CS/CE/R/C) and standalone mode (R/C edge-triggered), with dual-data-format selection via 12/8 and A0 pins.

It features on-chip three-state output buffers enabling direct 8-bit or 12-bit microprocessor bus interfacing, configurable byte-read sequencing, and status flag (STS) signaling conversion completion. Input impedance is 5 kΩ (10 VIN) or 10 kΩ (20 VIN), and analog common (AGND) is isolated from digital common (DGND).

Key Specifications

Pinout & Package

AD774BARZ is housed in a 28-lead plastic SOIC (R-28) package with gull-wing leads, 0.025" pitch, and JEDEC MS-013AC compliant outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD774BARZ, AD7819ARZ offers faster speed and lower voltage operation but requires external reference and lacks bipolar input support; AD1674JRZ provides identical pinout and built-in sample-and-hold at the cost of higher power and slower conversion, making it suitable for extended temperature or precision timing-critical deployments.

Availability

AD774BARZ is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, legacy system upgrades, and high-voltage data acquisition requiring stable component supply, long-lifecycle support, and guaranteed traceability.

Supply support for AD774BARZ 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, headquartered in Wilmington, MA.

The AD774B product line delivers complete, pin-compatible 12-bit SAR ADCs designed for precision data acquisition in industrial, military, and test instrumentation where reliability, calibrated input ranges, and legacy system interoperability are critical.

FAQ

What is the maximum conversion time specification for AD774BARZ?

The AD774BARZ has a maximum conversion time of 8 µs under specified conditions (+5 V VLOGIC, ±12 V or ±15 V analog supplies, –40°C to +85°C). This value applies to both 12-bit and 8-bit conversion cycles and is guaranteed across the full industrial temperature range. The 8 µs figure reflects worst-case timing including internal clock settling and SAR completion, enabling deterministic system-level timing budgets in real-time control loops.

Does AD774BARZ require external calibration components for ±10 V bipolar operation?

No, AD774BARZ does not require external calibration components for ±10 V bipolar operation. When BIP OFF (Pin 12) is connected to REF OUT (Pin 8) via a 50 Ω resistor and 20 VIN (Pin 14) is used as the analog input, the laser-trimmed internal resistors provide factory-calibrated ±10 V full-scale range. The AD774BARZ datasheet confirms ±1 LSB linearity and <±0.25% full-scale calibration error without user trimming-enabling out-of-box accuracy in high-voltage bipolar measurement systems.

Can AD774BARZ operate with only +5 V and ±12 V supplies, or are ±15 V required?

AD774BARZ operates fully within specification using +5 V (VLOGIC), +12 V (VCC), and –12 V (VEE) supplies. The datasheet explicitly lists ±12 V as a valid operating condition across all grades, including the AD774BARZ's industrial –40°C to +85°C range. Supply rejection specifications confirm ≤2 LSB full-scale error shift under ±12 V ±5% tolerance, making ±12 V the preferred choice for noise-sensitive applications where ±15 V switching regulators may introduce ripple.

How is the 10 V internal reference used in AD774BARZ, and can it drive external circuitry?

The AD774BARZ's internal 10.00 V ±1% reference is accessed at REF OUT (Pin 8) and is designed to drive both the internal DAC and external loads up to 2.0 mA total. To use it, connect REF OUT to REF IN (Pin 10) via a 50 Ω resistor. The reference remains stable during conversion only if external load current is constant; therefore, it can power bias networks or auxiliary op-amps-but not switching loads-without degrading ADC accuracy.

Is AD774BARZ pin-compatible with the AD574A, and what are the key electrical improvements?

Yes, AD774BARZ is fully pin-compatible with the industry-standard AD574A, sharing identical 28-pin SOIC (R-28) pinout and signal definitions. Key electrical improvements include 8 µs max conversion time (vs. 25 µs for AD574A), lower power consumption (375 mW vs. 550 mW), tighter linearity (±1 LSB vs. ±0.5 LSB typical), and integrated 10 V reference with 10 ppm/°C drift (vs. external reference dependency in AD574A). These enhancements enable direct drop-in upgrades in legacy systems.