AD7228ACR

Overview

The AD7228ACR is an octal 8-bit voltage-mode digital-to-analog converter (DAC) fabricated on LC2MOS technology. It integrates eight 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 channel, accessed via a common 8-bit TTL/CMOS-compatible data bus 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 specifications include a settling time of 5 µs to ±1/2 LSB, differential nonlinearity of ±1 LSB, and integral nonlinearity of ±1/2 LSB for the C version.

Feature Summary

• Octal architecture with eight independent 8-bit DACs and integrated output buffer amplifiers
• Microprocessor-compatible parallel interface with individual latch control via A0-A2 and WR signals
• Dual or single supply operation with reference voltage range from 2 V to 10 V
• High-speed performance with 95 ns minimum write pulse width and 5 µs settling time

Applications

• Automated test equipment requiring multi-channel signal generation
• Industrial process control systems with multiple analog outputs
• Data acquisition systems utilizing microprocessor interfaces
• Programmable power supplies and waveform generators

Procurement Notes

Verify the specific suffix 'CR' corresponds to the SOIC-24 surface-mount package variant when sourcing replacements. Confirm that the 'C' grade designation meets the required integral nonlinearity specification of ±1/2 LSB, as other grades in the family may differ. Ensure the design accommodates the 24-lead Skinny SOIC outline dimensions provided in the datasheet for proper PCB layout.

Selection Notes

Select this component when board space reduction is critical due to its integration of eight converters on one chip. Verify that the 2 kΩ minimum load resistance requirement aligns with the application's output impedance needs. For single-supply designs, ensure the reference voltage does not exceed 10 V and account for the slightly longer negative-going settling time near 0 V compared to dual-supply configurations.

Part Context

The AD7228 series utilizes LC2MOS technology to combine high-speed digital logic with precision analog circuits. The AD7228ACR specifically denotes the commercial temperature range (-40°C to +85°C) and the C grade accuracy level. It is part of a family offering various packages including PDIP, CERDIP, and PLCC, allowing flexibility in manufacturing and assembly processes while maintaining consistent functional performance across variants.

Replacement Considerations

Direct pin-compatible substitutes within the same package include the AD7228ABRZ and AD7228ACPZ-REEL. When replacing, verify that the substitute's accuracy grade (e.g., B vs. C) matches the system's linearity requirements. Ensure the replacement supports the same 24-lead SOIC footprint if using the CR variant.