AD7228ACN

Overview

The AD7228ACN is an octal 8-bit digital-to-analog converter (DAC) fabricated on LC2MOS technology. It integrates eight voltage-mode DACs with output buffer amplifiers and interface logic on a single monolithic chip, eliminating the need for external trims. The device features separate on-chip latches for each DAC, accessed via a common 8-bit TTL/CMOS-compatible input port controlled by A0, A1, and A2 address inputs and an active-low WR signal. It operates with dual supplies (VDD: 10.8 V to 16.5 V; VSS: -5 V ± 10%) or a single 15 V supply. Key electrical parameters include a settling time of 5 µs to ±1/2 LSB, a maximum total unadjusted error of ±2 LSB, and a reference voltage range of 2 V to 10 V.

Feature Summary

• Octal architecture with eight independent 8-bit DACs and individual output buffers.
• Microprocessor-compatible parallel interface with speed compatible with most 8-bit microprocessors (95 ns WR pulse).
• Operates from dual supplies (-5 V/VDD) or a single +15 V supply.
• LC2MOS process ensures high-speed linear performance without user trims.

Applications

• Automated test equipment requiring multiple analog outputs.
• Industrial control systems with multi-channel signal generation.
• Programmable power supplies and setpoint controllers.

Procurement Notes

Verify the package type matches the design requirements, as the AD7228 family includes SOIC, PLCC, and PDIP variants. Confirm the grade suffix (e.g., AC) aligns with the required accuracy specifications. Check current availability status, as older CMOS components may have limited stock or end-of-life implications. Ensure the ordering suffix corresponds to the specific tape-and-reel or tube packaging needed for assembly.

Selection Notes

Select the AD7228ACN when eight synchronized 8-bit voltage outputs are required in a compact footprint. Choose this part over higher-resolution DACs if cost and board space are primary constraints and 8-bit precision is sufficient. Verify that the system can accommodate the required reference voltage range (2 V to 10 V) and that the load impedance meets the minimum 2 kΩ requirement for specified performance.

Part Context

The AD7228 series is part of Analog Devices' legacy LC2MOS product line, designed for applications needing multiple low-cost, medium-speed DACs. The 'AC' suffix typically denotes a specific temperature range and accuracy grade within the family. The 'CN' suffix indicates the 24-lead Plastic Dual In-Line Package (PDIP), which is suitable for through-hole mounting and prototyping.

Replacement Considerations

Direct pin-for-pin replacements within the same package are limited due to the age of the LC2MOS process. Consider modern octal DACs from Analog Devices or other manufacturers if updated manufacturing support is required. Verify that any substitute maintains the parallel interface compatibility and settling time requirements of the original design.