NUVOTON ISD1750SY

The ISD1700 Series is a high quality, fully integrated, single-chip multi-message voice record and playback device ideally suited to a variety of electronic systems. The message duration is user selectable in ranges from 26 seconds to 120 seconds, depending on the specific device. The sampling frequency of each device can also be adjusted from 4 kHz to 12 kHz with an external resistor, giving the user greater flexibility in duration versus recording quality for each application. Operating voltage spans a range from 2.4 V to 5.5 V to ensure that the ISD1700 devices are optimized for a wide range of battery or line-powered applications. The ISD1700 is designed for operation in either standalone or microcontroller (SPI) mode. The device incorporates a proprietary message management system that allows the chip to self-manage address locations for multiple messages. This unique feature provides sophisticated messaging flexibility in a simple push-button environment. The devices include an on-chip oscillator (with external resistor control), microphone preamplifier with Automatic Gain Control (AGC), an auxiliary analog input, antialiasing filter, Multi-Level Storage (MLS) array, smoothing filter, volume control, Pulse Width Modulation (PWM) Class D speaker driver, and current/voltage output. The ISD1700 devices also support an optional “vAlert” (voiceAlert) feature that can be used as a new message indicator. With vAlert, the device flashes an external LED to indicate that a new message is present. Besides, four special sound effects are reserved for audio confirmation of operations, such as “Start Record”, “Stop Record”, “Erase”, “Forward”, “Global Erase”. Recordings are stored into on-chip Flash memory, providing zero-power message storage. This unique single-chip solution is made possible through patented Multi-Level Storage (MLS) technology. Audio data are stored directly in solid-state memory without digital compression, providing superior quality voice and music reproduction. Voice signals can be fed into the chip through two independent paths: a differential microphone input and a single-ended.