AD1955ARSZRL

Overview

The AD1955ARSZRL is a high-performance stereo digital-to-analog converter (DAC) from Analog Devices, housed in a 28-lead SSOP package. It supports 24-bit resolution and sample rates up to 192 kHz for PCM audio, as well as SACD DSD bit-stream playback. The device features an 8x oversampling digital filter, multibit sigma-delta modulation, and differential current outputs with an 8.64 mA p-p range. Key electrical specifications include a signal-to-noise ratio of 120 dB (stereo) and 123 dB (mono), -110 dB THD+N, and operation on a single 5 V supply within a -40°C to +85°C temperature range.

Feature Summary

• Supports 24-bit/192 kHz PCM and SACD DSD playback with internal digital filters or external filter interface
• High performance analog output: 120 dB SNR (stereo), -110 dB THD+N, and 8.64 mA p-p differential current output
• Flexible serial data interface compatible with I2S, Left-Justified, Right-Justified, and DSP modes
• On-chip clickless volume control, mute capability, and digital de-emphasis for 32, 44.1, and 48 kHz

Applications

• High-end DVD Audio systems
• Super Audio CD (SACD) players
• Home theater systems
• Automotive audio systems
• Digital mixing consoles

Procurement Notes

Verify the 'RL' suffix indicates reel packaging when sourcing. Confirm the specific revision of the datasheet matches the production batch requirements. Ensure ESD precautions are observed during handling due to the sensitivity of the CMOS input structure. Cross-reference the 28-lead SSOP footprint dimensions against the target PCB layout guidelines provided in the official documentation.

Selection Notes

Select this component for applications requiring high-fidelity audio conversion with integrated filtering. It is suitable for designs needing direct interface to DSPs or ADCs via its flexible serial port. Consider the 5 V supply requirement and the need for external I/V converters for the differential current outputs. Evaluate the thermal resistance characteristics if operating near the upper limit of the specified temperature range.

Part Context

The AD1955ARSZRL belongs to the AD1955 series of audio DACs. It is functionally identical to the AD1955ARSZ but differs in packaging quantity, with the RL suffix denoting tape-and-reel delivery. The EVAL-AD1955EBZ evaluation board is available for design verification. This part replaces older discrete solutions by integrating the modulator, filter, and DAC into a single monolithic IC.

Replacement Considerations

The AD1955ARSZ is the tube-packaged equivalent with identical electrical specifications. No other direct pin-compatible substitutes are documented in the primary source material.

FAQ

What master clock frequencies are supported?

The AD1955 supports master clock frequencies of 256fs, 512fs, and 768fs, where fs is the nominal sample rate.

How does the device handle SACD playback?

It supports SACD playback via a dedicated serial port accepting DSD bit streams in either Normal Mode (64fs) or Phase Modulation Mode (128fs).

What is the recommended analog output configuration?

Active I/V converters are required; passive conversion should not be used as it degrades performance. A reference voltage of 2.80 V is recommended for optimal THD+N.