ISD1820 Voice Recorder and Playback with Speaker

The main Voice Recorder/Playback IC is ISD1820.

This ISD1820 Voice Recorder/Playback Module reproduces high-quality, natural voice and audio from the recorded audio by Mic or driven through Microcontroller. Because of its dual operation mode (Standalone and Microcontroller driven), we can easily use this as per requirement and with a slight change of the onboard resistor, we can get flexibility in the sampling frequency of the recording duration & quality.

In this module, Voice signals can be fed through differential onboard microphone input.

For outputs, the module provides an 8Ω  

There are two modes to play the voice in the voice chip:

1. Playback, Edge-activated: If the module detects the HIGH signal on the pin, then the device starts the playback cycle. Playback cycle continues until an End-of-Message (EOM) marker is encountered or the end of the memory space is reached. After completion of the playback cycle, the device automatically powers down itself and into the standby mode.

2. Playback, Level-activated: If the module detects the LOW to HIGH signal on this pin, then a playback cycle is initiated. Playback continues until PLAYL is pulled LOW or an End-of-Message (EOM) marker is detected, or the end of the memory space is reached. The device automatically powers down to standby mode upon completion of the playback cycle.

Interfacing Diagram

The ISD1820 based voice recorder and playback module can easily be controlled using any microcontroller like PIC, Arduino, etc. via three digital I/O communication pins.

Application of ISD1820 Voice Recorder/Playback

• Voice Recorder
• Microcontroller based audio playback
• Sound recorder

2D Model

The dimensions of the ISD1820 Module is shown below-