AD1851RZ-REEL7

Overview

The AD1851RZ-REEL7 is a monolithic 16-bit PCM audio digital-to-analog converter (DAC) from Analog Devices, housed in a 16-pin SOIC package. It integrates a voltage reference, output amplifier, DAC, and serial-to-parallel register without requiring external components. The device operates on ±5 V analog supplies and a +5 V logic supply, supporting a maximum input clock frequency of 12.5 MHz. Key electrical specifications include a typical signal-to-noise ratio (SNR) of 110 dB, a total harmonic distortion plus noise (THD+N) of 0.004% at 0 dB, and a settling time of 1.5 μs for a 6 V step. It features a serial 2's complement interface compatible with standard digital filter chips.

Feature Summary

• 16-bit resolution with 110 dB SNR and 0.004% THD+N
• Integrated voltage reference and output amplifier
• Fast 1.5 μs settling time supports up to 16x oversampling
• Optional TRIM pin allows elimination of midscale differential linearity error

Applications

• High-end compact disc players
• Digital audio amplifiers
• DAT recorders and players
• Synthesizers and keyboards

Procurement Notes

Verify component status as the datasheet indicates this series is obsolete. Confirm that the REEL7 suffix denotes tape and reel packaging for surface-mount assembly. Ensure compatibility with existing ±5 V power rails and digital interfaces before integration into new designs.

Selection Notes

Select the AD1851RZ variant over the AD1861 when 16-bit resolution is sufficient, noting the lower maximum clock rate of 12.5 MHz compared to the AD1861's 13.5 MHz. Use the -J graded version if tighter THD+N specifications (0.004%) are required. Ensure the design accommodates separate analog and digital ground connections to minimize crosstalk.

Part Context

The AD1851/AD1861 series serves as a drop-in replacement for the AD1856 and AD1860 PCM audio DACs due to identical pinouts and functionality. It utilizes Analog Devices' 2 μm ABCMOS process for digital logic and bipolar/MOS technology for analog sections. The device is designed for home use markets requiring high-fidelity audio playback with low power dissipation.

Replacement Considerations

The AD1851RZ is pin-compatible with the AD1856 and AD1860. Designers replacing these legacy parts should verify that the ±5 V supply requirements and serial interface timing align with the system architecture.