Products for Audio and Speech Applications

Many 16-bit PIC24 microcontrollers (MCUs) and dsPIC^® Digital Signal Controllers (DSCs) offer on-chip Flash memory up to 256 KB. Some 16-bit MCUs and DSCs offer 128 KB of on-chip Flash memory in a 6 × 6 mm QFN package with a specialized 16-bit DAC peripheral. The PIC32 MCU offers up to 2 MB of on-chip Flash memory making these products ideal to store large segments of voice messages within on-chip Flash memory, reducing component count and lowering your system cost.

dsPIC DSCs offer these specialized peripherals for audio applications:

• 16-bit DAC
• Codec/data converter Interface module
• 1 nanosecond SMPS PWM

dsPIC DSCs offer an industry-unique on-chip 16-bit DAC peripheral for audio applications. Another audio peripheral, the Codec Interface, is a 4-wire serial communication peripheral used to stream audio data to and from an external stereo 16-bit codec, DAC or ADC. The Codec Interface peripheral supports AC-97, I2S and a simple time-division multiplex mode. Many dsPIC DSCs are equipped with high-frequency motor control and SMPS Pulse-Width Modulation (PWM) peripherals, which enable driving the speakers with higher-quality audio (better resolution in bits) in Class D audio amplifier applications.

Many PIC® MCUs and dsPIC DSCs offer an on-chip 12-bit ADC peripheral module. The 12-bit resolution may be sufficient in many cases for recording speech signals from a microphone. If resolution greater than 12 bits is desired, the Codec Interface peripheral can be used in conjunction with an external 16-bit ADC or audio codec to record sound.

Nearly all of our 8-, 16- and 32-bit general-purpose MCUs and DSCs feature the standard PWM peripheral that can be used in audio playback applications. The PWM output is typically provided to a low-pass filter prior to an amplification stage that drives the speaker unit.