NUVOTON ISD3800FYI

The ISD3800 is a digital ChipCorder featuring digital compression, comprehensive memory management, and integrated analog/digital audio signal paths. The ISD3800 utilizes serial flash memory to provide non-volatile audio playback for a two-chip solution. The ISD3800 provides an I²S digital audio interface, faster digital programming, higher sampling frequency, and a signal path with SNR 80dB. The ISD3800 can take digital audio data via I²S or SPI interface. When I²S input is selected, it will replace the analog audio inputs and will support sample rates of 32, 44.1 or 48 kHz depending upon clock configuration. When SPI interface is chosen, the sample rate of the audio data sent must be one of the ISD3800 supported sample rates. The ISD3800 has inbuilt analog audio inputs, analog audio line driver, and speaker driver output. The analog audio input, Aux-in, has a fixed gain configured by SPI command. Aux-in can directly feed-through to the analog outputs; it can also mix with the DAC output and then feed-through to the analog outputs. Analog outputs are available in two forms: (1) Aux-out is an analog single-ended voltage output; (2) Class-AB BTL (bridge-tied-load) is an analog differential voltage output. Class-AB BTL delivers 1-watt output power at VCCSPK = 5V. Class-D PWM direct-drive is also available, which delivers 1-watt output power at VCCSPK = 5V.

• External Memory: The ISD3800 supports the following flash. The addressing ability of ISD3800 is up to 128Mbit, which is 64-minute playback time based on 8kHz/4bit ADPCM. Inbuilt 3V voltage regulator to provide power source to the external flash memory
• Fast Digital Programming
• Memory Management: Store pre-recorded audio (Voice Prompts) using high quality digital compression. Use a simple index-based command for playback. Execute pre-programmed macro scripts (Voice Macros) designed to control the configuration of the device and play back Voice Prompts sequences.
• Sample Rate: Seven sampling frequencies are available for a given master sample rate. For example, the sampling frequencies of 4, 5.3, 6.4, 8, 12.8, 16 and 32kHz are available when the device is clocked at a 32kHz master sample rate. For I²S operation, 32, 44.1 and 48kHz master sample rates are available with playback sampling frequencies scaling accordingly.
• Compression Algorithms: For Pre-Recorded Voice Prompts μ -Law: 6, 7 or 8 bits per sample. Differential μ -Law: 6, 7 or 8 bits per sample. PCM: 8, 10 or 12 bits per sample. Enhanced ADPCM: 2, 3, 4 or 5 bits per sample. Variable-bit-rate optimized compression. This allows best possible compression given a metric of SNR and background noise levels.
• Oscillator: Internal oscillator with internal reference: 2.048 MHz with ±1% deviation. Internal oscillator with external resistor: 2.048 MHz with ±2% deviation. External crystal or clock input. Crystals support standard audio sampling rates of 2.048, 4.096, 8.192, 12.288 and 11.2896MHz. I2S bit clock input
• Inputs: Aux-in: Analog input with 2-bit gain control configured by SPI command
• Outputs: PWM: Class-D speaker driver to directly drive an 8Ω speaker or buzzer. Deliver 1-watt output power at VCCSPK = 5V. Aux-out: an analog single-ended voltage output. Class-AB BTL: an analog differential voltage output. Deliver 1-watt output power at VCCSPK = 5V. Class-AB BTL can directly drive an 8Ω speaker or buzzer. Class-AB BTL can drive an 8Ω speaker or buzzer via an external amplifier
• I/Os: SPI interface: MISO, MOSI, SCLK, SSB for commands and digital audio data. I²S interface: I2S_CLK, I2S_WS, I2S_SDI, I²S_SDO for digital audio data. 8 GPIO pins: 4 GPIO pins share with I²S. 4 GPIO pins share with SPI Interface. GPIO pins can trigger Voice Macro for a pushbutton application
• 8-bit Volume Control set by SPI command for flexible mixing
• Operating Voltage: 2.7~5.5V
• Standby Current: 1uA typical