ISD1420SI

Overview

The ISD1420SI is a single-chip voice record/playback device from the ISD1400 series, manufactured by Nuvoton Technology Corporation. It provides 20 seconds of recording duration with a sampling frequency of 6.4 kHz and a filter passband of 2.6 kHz. The component operates on a single +5V supply (4.5V to 5.5V) and features an internal oscillator. It utilizes Multi-Level Storage technology for non-volatile memory, supporting 100,000 record cycles and 100-year message retention. The device is housed in a 28-lead 300 mil Plastic Small Outline IC (SOIC) package.

Feature Summary

• Direct analog storage using patented Multi-Level Storage technology for natural voice reproduction without digitization or compression.
• Integrated microphone preamplifier with automatic gain control and anti-aliasing/smoothing filters.
• Built-in operational modes including message cueing, looping, consecutive addressing, and EOM marker deletion.
• Automatic power-down to standby mode after record or playback cycles to minimize current consumption.

Applications

• Short-duration messaging systems requiring manual switch or microcontroller control.
• Voice prompts and announcements in consumer electronics.
• Educational toys and novelty items utilizing push-button interfaces.
• Training equipment voice circuits integrated with BTL power amplifiers.

Procurement Notes

Verify the specific SOIC package variant against the datasheet pinout. Confirm that the lead-free designation aligns with environmental compliance requirements. Check for obsolescence status as older ISD series components may have limited availability. Ensure the supplier provides valid traceability documentation for the Nuvoton/Winbond origin.

Selection Notes

Select this model when a 20-second duration at 6.4 kHz sampling rate is required. Choose the SOIC package for surface-mount assembly needs. Consider external clocking via the XCLK pin if higher timing precision than the internal oscillator allows is necessary. Verify that the 16Ω speaker impedance matches the direct drive capability of the SP+ and SP- outputs.

Part Context

The ISD1420SI belongs to the ISD1400 series of ChipCorder devices, which also includes the ISD1416 (16-second duration). These CMOS devices integrate all necessary functions for voice recording and playback into a single chip, eliminating the need for external digital signal processors or flash memory controllers.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided source material. Designers should verify compatibility with newer ISD series variants if sourcing new production units, noting potential differences in packaging or operational mode definitions.