Analog Devices Inc. AD7228KR-REEL

Overview

AD7228KR-REEL from Analog Devices is an LC2MOS octal 8-bit voltage-mode DAC with integrated output buffer amplifiers, designed for precision analog output generation in microprocessor-controlled systems. It features eight independent DACs, 8-bit resolution, ±1 LSB relative accuracy (K-grade), and operates from single (15 V) or dual (±5 V) supplies. Each output drives 10 V into a 2 kΩ load and supports unipolar/bipolar configurations via external circuitry.

For engineers reviewing the AD7228KR-REEL datasheet, AD7228KR-REEL pinout, AD7228KR-REEL application, or AD7228KR-REEL equivalent, key selection criteria include guaranteed monotonicity, 95 ns WR pulse compatibility with 8-bit microprocessors, 5 µs settling time to ±1/2 LSB, low digital crosstalk (50 nV·sec), and support for programmable reference and coarse/fine adjustment architectures.

Technical Context

The AD7228KR-REEL integrates eight identical R-2R ladder DACs with NMOS switching and on-chip unity-gain CMOS op amps-each delivering 2 V/µs slew rate and 300 µV_p-p broadband noise. Its address-decoded latch architecture (A0–A2 + WR) enables selective loading of individual DAC registers without bus contention.

Dual-supply operation (VDD = 15 V, VSS = −5 V) extends VREF range to 2–10 V and improves negative-going settling time versus single-supply mode. The device uses LC2MOS process technology to co-integrate high-speed digital logic and precision analog circuits on one die, eliminating external trims for full-specified performance.

Key Specifications

Pinout & Package

AD7228KR-REEL is supplied in a 24-lead SOIC package (width 0.300", JEDEC MS-012). All analog outputs (VOUT1–VOUT8), VREF, VSS, and GND are located on one side; digital I/O (DB0–DB7, A0–A2, WR) and power (VDD) occupy the opposite side-enabling clean PCB layout separation of analog and digital domains.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal DAC applications.

Compared with AD7228LN and MAX524CPE+, the AD7228KR-REEL uniquely combines parallel microprocessor interface timing, SOIC packaging for automated assembly, and guaranteed monotonicity across −40°C to +85°C-making it optimal for retrofitting legacy industrial controllers and ATE systems requiring deterministic write-cycle behavior.

Availability

AD7228KR-REEL is available at Aetrix Electronics and suitable for automated test equipment, industrial process control, precision calibration, and data acquisition systems requiring stable component supply and long-term obsolescence management.

Supply support for AD7228KR-REEL 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 Norwood, MA.

The AD7228KR-REEL belongs to Analog Devices' precision DAC product line, engineered specifically for applications demanding multi-channel analog output generation with microprocessor compatibility, monotonicity assurance, and minimal external component count.

FAQ

What is the maximum reference voltage supported by the AD7228KR-REEL?

The AD7228KR-REEL supports a reference voltage range of 2 V to 10 V when operated with dual supplies (VDD = 15 V, VSS = −5 V). In single-supply mode (VDD = 15 V, VSS = GND), the specified VREF is 10 V. Exceeding 10 V violates absolute maximum ratings and risks permanent damage. The device's R-2R ladder and buffer amplifier are characterized and guaranteed only within this 2–10 V window.

Does the AD7228KR-REEL require external trimming for full accuracy?

No, the AD7228KR-REEL requires no user trims. Its LC2MOS process incorporates factory-laser-trimmed thin-film R-2R ladders and matched NMOS switches, ensuring ±1 LSB relative accuracy and monotonicity over temperature without external calibration. This eliminates potentiometers, trim caps, or post-assembly adjustment steps in production.

Can the AD7228KR-REEL operate from a 5 V single supply?

Yes, the AD7228KR-REEL supports 5 V single-supply operation (VDD = 5 V, VSS = GND), though with slightly degraded accuracy: relative accuracy degrades to ±1 LSB typical (vs. ±1 LSB max in 15 V mode), and VREF is limited to 1.23 V. Power dissipation drops to ~50 mW. Digital input thresholds remain compatible with standard TTL/CMOS logic levels.

How does the AD7228KR-REEL handle digital crosstalk between DAC channels?

The AD7228KR-REEL limits digital crosstalk to 50 nV·sec typical-measured as glitch impulse transferred to an unaddressed DAC output during a full-scale code change on another channel. This low value results from on-chip isolation design and LC2MOS process optimization, ensuring stable outputs on idle channels during rapid multi-DAC updates.

What microprocessor families are directly compatible with the AD7228KR-REEL interface?

The AD7228KR-REEL is directly compatible with 8-bit microprocessors including Intel 8085A (with demultiplexed address/data), Zilog Z80, Motorola 6809/6502, 68008, and Intel 8051. Its 95 ns WR pulse width, level-sensitive address decoding (A0–A2), and TTL/CMOS input thresholds eliminate need for wait-state generators or interface logic in these architectures.