ISD4002-120E

Overview

The ISD4002-120E is a single-chip voice record/playback device from the ChipCorder series, designed for 120-second messaging applications. It operates on a single 3V supply and features an internal oscillator with a sampling frequency of 8.0 kHz. The device utilizes non-volatile multilevel Flash memory to store analog audio signals directly, eliminating the need for digitization or compression algorithms. Control is managed via a four-wire SPI interface, allowing fully addressable multiple message handling. Key electrical parameters include a typical operating current of 15 mA during playback and 25 mA during recording, with a standby current of 1 µA. The filter passband is specified at 3.4 kHz.

Feature Summary

• Direct analog storage in non-volatile Flash memory for high-quality natural voice reproduction without digital compression.
• Integrated AutoMute feature that attenuates background noise by 6 dB during silence periods.
• Fully addressable memory architecture supporting multiple messages controlled through a standard SPI interface.
• On-chip clock source with options for external clock input to ensure precise sampling frequency stability.

Applications

• Cellular phones and portable communication devices requiring low-power voice messaging.
• Microcontroller-based systems needing simple, single-chip voice recording and playback solutions.
• Portable products where zero-power message storage and minimal pin count are critical design constraints.

Procurement Notes

Verify the specific package type (TSOP, SOIC, or PDIP) required for the target application, as the ISD4002 series is available in multiple form factors. Confirm the temperature grade (Commercial, Extended, or Industrial) matches the environmental operating conditions. Ensure the power supply voltage remains within the 2.7V to 3.3V range to maintain specified performance characteristics and timing parameters.

Selection Notes

Select the ISD4002-120 variant specifically when a 120-second recording duration at an 8.0 kHz sampling rate is required. Consider the ISD4002-150, -180, or -240 models if longer durations are needed, noting that these variants operate at lower sampling frequencies and narrower filter passbands. Evaluate the need for external clocking via the XCLK pin if higher frequency precision than the internal oscillator provides is necessary for the application.

Part Context

The ISD4002-120E belongs to the ISD4002 ChipCorder series, which includes variants with durations of 120, 150, 180, and 240 seconds. This series represents a CMOS-based solution integrating analog transceivers, filters, and high-density Flash memory on a single die. The technology allows for direct analog signal storage, distinguishing it from digital voice codecs that require complex algorithmic processing for compression and decompression.

Replacement Considerations

Publicly confirmed substitute part numbers for the ISD4002-120E are not available in the provided documentation. The datasheet indicates the series was originally manufactured by Winbond, while later distributor listings associate the brand with Nuvoton Technology Corporation. Verify compatibility with any legacy components if replacing older designs.

FAQ

How does the ISD4002 handle audio input signals?

The device accepts analog speech samples directly into its non-volatile memory. It supports both single-ended and differential input modes via the ANA IN+ and ANA IN- pins, with maximum input signals of 32 mVp-p for single-ended and 16 mVp-p for differential configurations.

What is the function of the RAC pin?

The Row Address Clock (RAC) pin provides an open-drain output signal with a period corresponding to one row of memory (e.g., 200 ms for 8 kHz sampling). It is used for message management techniques and memory addressing control during record and playback operations.

Can the ISD4002 be used for playback-only applications?

Yes, the device is suitable for playback-only applications. Messages can be pre-recorded using a programmer, and subsequent playback is controlled entirely through the SPI port without requiring further recording capabilities.