Analog Devices Inc. AD1893JST

Overview

AD1893JST from Analog Devices is a 16-bit stereo asynchronous sample rate converter (ASRC) designed for digital audio interfacing between mismatched sample clocks (e.g., 44.1 kHz CD ↔ 48 kHz DAT). It operates from 2.7–5.5 V, achieves –96 dB THD+N at 1 kHz, supports 8–56 kHz input/output sample rates with 1:2 to 2:1 ratio flexibility, and features on-chip 16 MHz oscillator for crystal-based timing. It targets battery-powered consumer audio recorders and networked multimedia systems.

For engineers reviewing the AD1893JST datasheet, AD1893JST pinout, AD1893JST application, or AD1893JST equivalent, key selection considerations include its automatic sample frequency sensing, jitter rejection up to 10 ns (slow mode), linear-phase FIR filtering with 110 dB stopband attenuation, 700–3000 µs group delay, and LQFP-44 package compatibility with portable audio BOMs.

Technical Context

The AD1893JST implements asynchronous conversion via polyphase FIR filter bank with 65,536 equivalent subfilters, operating at an internal 3.2768 GHz convolution rate and 300 ps time resolution. Its digital servo control loop continuously computes the LR_I/LR_O ratio to drive FIFO read addressing and coefficient ROM selection without external programming.

It supports independent input/output serial interface configurations-including right-justified, left-justified, and word-clock-triggered modes-with programmable bit clock polarity (BKPOL_I/O) and dual-mode settling (SETSLW pin selects ≈200 ms fast or ≈800 ms slow loop response), enabling real-time adaptation to dynamic sample rate changes while maintaining ≤0° interchannel phase deviation.

Key Specifications

Pinout & Package

AD1893JST is housed in a 10 mm × 10 mm LQFP-44 package with exposed thermal pad (ST-44), rated for 0°C to +70°C operation. Pin functions are validated per Analog Devices AD1893 datasheet Rev. A (pages 5–7).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar asynchronous sample rate conversion applications.

Compared with AK4118VN and CS8422-CQZ, AD1893JST uniquely combines crystal-based self-timing, automatic rate sensing, dual-mode jitter rejection, and 3 V operation-making it the only option qualified for cost-sensitive, battery-powered, multi-standard consumer audio recorders requiring zero-configuration interoperability.

Availability

AD1893JST is available at Aetrix Electronics and suitable for consumer audio recorders, digital audio networking equipment, and computer multimedia systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AD1893JST includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, communications, and industrial applications.

The AD1893JST belongs to the SamplePort® family of asynchronous sample rate converters, engineered specifically for low-cost, low-power digital audio bridging in portable and consumer electronics where battery life, board space, and multi-standard compatibility are critical.

FAQ

What is the primary function of the AD1893JST in a digital audio system?

The AD1893JST serves as a fully digital stereo asynchronous sample rate converter that bridges mismatched input and output sample clocks-such as 44.1 kHz CD audio and 48 kHz DAT streams-without requiring shared timing references or firmware configuration. Its core function is to maintain audio fidelity during real-time resampling by dynamically computing the LR_I/LR_O ratio and applying linear-phase FIR filtering. The AD1893JST achieves this with –96 dB THD+N and 96 dB dynamic range while operating from a single 3 V supply.

Does the AD1893JST require external programming to handle different sample rates like 32 kHz, 44.1 kHz, or 48 kHz?

No, the AD1893JST does not require external programming or register writes to handle 32 kHz, 44.1 kHz, or 48 kHz sample rates. It automatically senses the relationship between the input (LR_I) and output (LR_O) sample clocks and adapts its internal interpolation/decimation ratio accordingly. This auto-sensing capability covers the full 8–56 kHz range and supports dynamic rate changes-even mid-stream-making the AD1893JST ideal for multi-standard consumer audio devices where manual configuration is impractical.

How does the SETSLW pin affect the performance of the AD1893JST?

The SETSLW pin configures the AD1893JST's digital servo control loop settling time: HI selects slow mode (≈800 ms settling, >3 Hz jitter rejection), optimizing for maximum signal quality in static-rate applications; LO selects fast mode (≈200 ms settling), enabling rapid tracking of real-time sample rate variations at the cost of narrowband noise modulation. This pin is asynchronous and can be changed dynamically-allowing the AD1893JST to adapt its behavior based on operational context without resetting or reinitialization.

Can the AD1893JST operate from a 3.0 V supply, and what is its typical current draw at that voltage?

Yes, the AD1893JST is fully specified for operation from 2.7 V to 5.5 V, with guaranteed performance at 3.0 V. At 3.0 V supply and typical conditions (FSIN = 48 kHz, FSOUT = 44.1 kHz), its operational current is 15–20 mA, and power-down current drops to 0.5–1.0 mA. This low-voltage, low-power profile makes the AD1893JST especially suitable for battery-powered portable audio recorders where energy efficiency directly impacts runtime.

What package type and pin count does the AD1893JST use, and is it compatible with standard PCB assembly processes?

The AD1893JST uses a 44-pin LQFP (ST-44) package measuring 10 mm × 10 mm with an exposed thermal pad, compliant with JEDEC MS-026. It is compatible with standard surface-mount reflow processes including lead-free soldering (up to 300°C for 10 seconds). The pinout is fully documented in the Analog Devices AD1893 datasheet Rev. A, and the package supports automated optical inspection and X-ray verification-ensuring high-yield manufacturing for consumer audio production lines.