ISD1420PI

Overview

The ISD1420PI is a single-chip voice record and playback device from the ISD1400 series, manufactured by Nuvoton Technology Corporation. It provides a 20-second recording duration with a sampling frequency of 6.4 kHz and a filter passband of 2.6 kHz. The IC operates on a single +5V supply (4.5 V to 5.5 V) and features an internal oscillator. Key electrical parameters include a typical standby current of 1 µA and an operating current of 30 mA. It utilizes patented Multi-Level Storage (MLS) technology for non-volatile message storage, supporting up to 100,000 record cycles. The component is housed in a 28-PDIP package.

Feature Summary

• Direct analog storage using Multi-Level Storage (MLS) technology for natural voice reproduction without digitization or compression.
• Integrated microphone preamplifier with Automatic Gain Control (AGC) and anti-aliasing/smoothing filters.
• Fully addressable architecture allowing for multiple message handling via external address pins.
• Automatic power-down mode that minimizes standby current consumption after record or playback cycles.

Applications

• Short-duration messaging systems requiring push-button operation
• Voice annotation and labeling devices
• Educational toys and interactive learning aids
• Industrial control panels with voice feedback

Procurement Notes

Verify the specific suffix 'PI' against the manufacturer's ordering guide to confirm the package type and temperature range. The datasheet indicates availability in PDIP and SOIC packages. Confirm end-of-life status and lead times with authorized distributors, as this component may be subject to obsolescence. Ensure the supply voltage matches the required +5V specification for proper operation.

Selection Notes

Select the ISD1420PI when a fixed 20-second duration is sufficient for the application. Compare against the ISD1416 if a shorter 16-second duration with higher sampling frequency (8.0 kHz) is preferred. Consider the ISD1700 series for applications requiring microcontroller interface or longer durations. Verify that the 28-pin PDIP package fits the PCB layout constraints and that the commercial temperature range meets environmental requirements.

Part Context

The ISD1420PI belongs to the Winbond/Nuvoton ISD1400 ChipCorder series, designed for low-cost, single-chip voice solutions. This series differentiates itself by storing audio signals directly in non-volatile memory cells, eliminating the need for external codecs or digital signal processors. It is part of a family that includes variants like the ISD1416 and ISD14B20, offering different durations and packaging options.

Replacement Considerations

The ISD1420PY is a pin-compatible alternative within the same series, differing primarily in the package type (PDIP vs. potentially other variations). For upgraded functionality, the ISD1700 series offers microcontroller compatibility and variable duration. Direct replacements should maintain the 28-pin DIP footprint and +5V operation.

FAQ

How does the ISD1420PI handle automatic gain control?

The device includes an on-chip Automatic Gain Control (AGC) circuit that dynamically adjusts the microphone preamplifier gain from -15 to 24 dB. This compensates for varying input levels, allowing recordings from whispers to loud sounds with minimal distortion.

What is the mechanism for message retention?

Messages are stored in on-chip non-volatile Multi-Level Storage (MLS) arrays. This technology allows for zero-power message storage, retaining data for up to 100 years typically without any battery backup circuitry.

Can the ISD1420PI be used for multiple messages?

Yes, the device is fully addressable. By utilizing the A0-A7 address pins, users can define start addresses for record and playback cycles, enabling the storage and retrieval of multiple distinct messages within the chip's memory space.