ISD1740SYIR

Overview

The ISD1740SYIR is a single-chip multi-message voice record and playback device from Nuvoton’s ChipCorder series. It features non-volatile message storage using patented Multi-Level Storage (MLS) technology, allowing for robust data retention without external backup power. The device supports user-selectable sampling frequencies ranging from 4 kHz to 12 kHz via an external resistor, which also determines the recording duration. It operates on a supply voltage of 2.4 V to 5.5 V and includes an internal oscillator, microphone preamplifier with Automatic Gain Control (AGC), volume control, and a PWM Class D speaker driver. The component is housed in a 28-SOIC package.

Feature Summary

• Integrated Multi-Level Storage (MLS) array for non-volatile message management
• Built-in microphone preamplifier with Automatic Gain Control (AGC)
• Direct drive capability for speakers or buzzers via PWM Class D output
• Flexible interface support for standalone button operation or SPI microcontroller control

Applications

• Electronic greeting cards and toys
• Voice-enabled home appliances and consumer electronics
• Industrial alarm systems and safety announcements
• Automotive interior voice prompts and notifications

Procurement Notes

Verify the specific suffix 'SYIR' against the manufacturer's current datasheet to confirm package type and tape-and-reel specifications. Check for End-of-Life (EOL) notices or Product Change Notifications (PCN) as legacy audio ICs may have limited availability. Ensure the supplier provides original manufacturer documentation to validate authenticity and RoHS compliance status before purchase.

Selection Notes

Select this model when a fixed message duration between 20 and 60 seconds is required at standard sampling rates. Compare against the ISD1730 series for shorter durations or the ISD1760/1790 series for longer recording times. Verify that the system design accommodates the 28-SOIC footprint and that the power supply range aligns with the 2.4 V to 5.5 V operational requirements of the ChipCorder architecture.

Part Context

The ISD1740 belongs to the broader ISD1700 ChipCorder family, which utilizes proprietary MLS technology to eliminate the need for external flash memory or battery backups for voice data. This series is designed to simplify voice integration into electronic products by combining analog front-end processing, digital storage, and power amplification into a single integrated circuit solution.

Replacement Considerations

Publicly confirmed direct substitutes are not available in the provided source material. Consider evaluating other members of the ISD1700 series, such as the ISD1730 or ISD1760, if duration requirements differ. Verify pin-to-pin compatibility and software register configurations before attempting any cross-model replacement.