ISD3900FYI

Overview

The ISD3900FYI is a multi-message ChipCorder featuring digital compression, comprehensive memory management, and integrated analog/digital audio signal paths. It utilizes external Winbond 25X/25Q series flash memory for non-volatile audio storage, supporting up to 128Mbit addressing. The device supports I2S or SPI interfaces with sample rates of 32, 44.1, or 48 kHz. Operating voltage ranges from 2.7V to 3.6V, with a typical standby current of 1µA. It features an internal oscillator at 2.048 MHz, seven record/playback sampling frequencies, and multiple compression algorithms including ADPCM and PCM. The package is LQFP-48, rated for -40°C to +85°C.

Feature Summary

• Supports address-free recording with automatic memory allocation and returns start addresses via SPI interface.
• Integrates Class-D PWM speaker driver and configurable single-ended or differential line drivers for flexible audio output options.
• Provides three independent 8-bit volume controls for mixing digital audio data, decompressed audio, and master outputs.

Applications

• Voice prompts and pre-recorded message playback systems
• Digital voice recording devices requiring external flash storage
• Interactive educational toys and learning aids

Procurement Notes

Verify the ordering suffix 'FYI' corresponds to the LQFP-48 package, industrial temperature range (-40°C to +85°C), and compliant packaging materials. Confirm that the required external flash memory is compatible with the ISD3900's serial interface specifications before finalizing procurement.

Selection Notes

Select this component when system design requires external flash memory expansion for extended recording times beyond internal limits. Ensure the host microcontroller supports the required SPI or I2S protocols. Verify power supply stability within the 2.7V to 3.6V range to maintain optimal SNR and output power performance.

Part Context

The ISD3900 belongs to Nuvoton's ISD ChipCorder series, designed for voice recording and playback applications. It differs from other series by offering an I2S digital audio interface and faster digital programming capabilities. The FYI variant specifically denotes the industrial temperature grade and green package compliance.

Replacement Considerations

Check datasheets for ISD3800 or ISD3900 variants with different suffixes for package or temperature changes. Ensure any substitute maintains compatibility with Winbond 25X/25Q flash memory and supports the same I2S/SPI interface requirements.

FAQ

What types of compression algorithms does the ISD3900 support?

The ISD3900 supports ADPCM (2, 3, 4, or 5 bits per sample), µ-Law (6, 7, or 8 bits), Differential µ-Law (6, 7, or 8 bits), and PCM (8, 10, or 12 bits) for recording. Pre-recorded prompts also support Enhanced ADPCM and Variable-bit-rate optimized compression.

How is the analog input gain configured?

The AUXIN input has a fixed gain configured by SPI command with 2-bit gain control. The ANAIN/ANAOUT input uses a variable gain amplifier where the gain is set by two external resistors connected between ANAOUT and ANAIN.

Can the ISD3900 operate without an external crystal?

Yes, the ISD3900 includes an internal oscillator with an internal reference providing 2.048 MHz with ±10% deviation. Alternatively, it can use an external resistor for ±5% deviation or an external crystal/clock input.