The note introduces the AD1856 and AD1851 16‑bit DACs, describing their supply requirements, harmonic distortion, and signal‑to‑noise performance. It also outlines the features of the Philips SAA7220 digital filter, including its passband attenuation and suitability for audio applications.
A detailed interface circuit is presented that adapts the SAA7220 output to the DAC inputs, using NAND gates and flip‑flops to align clocking and latch signals. The document discusses filter design choices, presents Bessel filter implementation, and reports combined system performance with low THD‑N and high SNR.
| AD1856 supply voltage | +5 V to +12 V |
|---|---|
| AD1851 THD+N and SNR | 0.004% THD+N, ≥107 dB SNR |
| SAA7220 passband attenuation | 1.0 dB at 20 kHz |
The AD1856 operates with a supply voltage between +5 V and +12 V.
The AD1851 has a maximum THD+N of 0.004% and a signal‑to‑noise ratio of at least 107 dB.
It provides 1.0 dB of digital pre‑emphasis in the 20 kHz passband.