**AD1851RZ-REEL7: A Comprehensive Technical Overview of the 24-Bit, 96 kHz Digital-to-Analog Converter**
The **AD1851RZ-REEL7** from Analog Devices represents a significant milestone in the evolution of high-fidelity audio digital-to-analog conversion. This integrated circuit is a **complete, 24-bit, 96 kHz stereo DAC** engineered to deliver exceptional audio performance for professional and high-end consumer applications. Its architecture is designed to minimize distortion and maximize dynamic range, making it a cornerstone component in premium audio equipment.
A core feature of the AD1851 is its use of a **multi-bit sigma-delta (Σ-Δ) modulation** technique. Unlike single-bit architectures, this multi-bit approach inherently reduces quantization noise and minimizes idle-tone patterns, resulting in a cleaner, more accurate analog output. The DAC operates with **24-bit resolution**, ensuring that even the most subtle details in the audio signal are preserved and reproduced with stunning clarity. Its capability to handle sampling rates up to **96 kHz** allows it to accurately process the entire spectrum of high-resolution audio sources, far beyond the range of human hearing.
The device incorporates **on-chip digital filtering** and **oversampling interpolation filters**. The digital filter is a critical component that removes out-of-band noise and images from the digital signal before it reaches the DAC stage. This process, combined with 8x oversampling, simplifies the design of the external analog reconstruction filter, which can now be a simpler, lower-order design, reducing phase shift and preserving audio quality.
The analog section of the AD1851 is equally impressive. It features **dual differential current-output DACs**, which are followed by sophisticated **on-chip analog deglitching circuits** and a **switched-capacitor low-pass filter**. This integrated approach minimizes external component count and ensures superior channel separation and stereo imaging. The output is designed to drive an external operational amplifier (op-amp) to convert the current signal into a voltage, providing designers with flexibility in tailoring the final output stage to specific sonic goals.
Key performance specifications underscore its high-end status. The AD1851 boasts a **dynamic range of typically 110 dB** and a **total harmonic distortion plus noise (THD+N) figure of -100 dB**. These figures translate to an incredibly quiet background and a near-total absence of audible distortion, allowing the pure, uncolored audio signal to pass through. The device supports standard audio interface formats, including **left-justified, right-justified, and I²S**, ensuring broad compatibility with a wide range of digital audio sources and digital signal processors (DSPs).
In application, the AD1851RZ-REEL7 is supplied in a compact 16-lead SOIC package and is ideal for use in a variety of premium products, including **professional audio mixing consoles, high-end CD/DVD players, digital audio workstations (DAWs), and audiophile-grade digital preamplifiers**. Its combination of integrated features and stellar performance metrics made it a preferred choice for designers seeking to achieve reference-level audio quality.
**ICGOODFIND:** The AD1851RZ-REEL7 stands as a testament to Analog Devices' engineering prowess in high-resolution audio. Its multi-bit sigma-delta architecture, integrated digital and analog filtering, and exceptional performance specs like **110 dB dynamic range** make it a quintessential component for any design demanding true high-fidelity audio reproduction.
**Keywords:** 24-Bit DAC, Sigma-Delta Modulation, 96 kHz Sampling, Dynamic Range, Digital Filter
