Audio Speakers-on-a-Chip Speakers-on-a-Chip with On-chip Audio DSP, Integrated I2S/I2C/USB Codec, and Class-D Amplifier CX20705 Conexant’s portfolio includes a comprehensive suite of semiconductor solutions for communications and consumer applications. The CX20705 is one of Conexant’s Speakers-on-a-Chip (SPoC) embedded audio solutions for designing 2.1 Channel audio entertainment applications. The device features a proprietary Digital Signal Processor (DSP), Codec, stereo 2.5 Watt Class-D amplifier, capless headphone driver, digital Crossover, and I2S, USB, and I2C interfaces in a cost-effective single-chip package. The solution features a suite of turnkey audio post-processing effects specifically designed for 2.1 Channel audio entertainment applications such as Smartphone/iPOD docking systems and All-In-One speakers. This product is part of the CX2070x SPoC family, which includes CX20702, CX20703, CX20704, CX20706, CX20707 and CX20709. The device features multiple high performance 24-bit DACs for 2.1 Channel speaker output, multiple 24-bit high performance ADCs supporting up to three stereo line inputs, capless headphone output, support for bi-directional I2S, PCM, S/PDIF-out with independent sampling rates, and a range of digital and analog input/output channel selections for flexible routing and mixing. The integrated digital crossover supports sub-woofer configuration. Different audio sampling rates ranging from 8 kHz to 96 kHz are generated directly from the master clock without the need for external PLL. The power-efficient Class-D amplifier drives a maximum of 2.5 W (average) stereo from the integrated amplifier. The SPoC can be controlled and configured by both read and write capability through I2C and Serial Peripheral Interface (SPI). The USB interface is USB 2.0 Audio Class compliant for both control and data. The on-chip Digital Signal Processor (DSP) runs a suite of innovative Conexant proprietary audio post processing effects that dramatically improves sound quality and frees-up processing power for other applications without compromising on cost and future firmware scalability. Key audio innovations include Equalizer, Dynamic Range Compression, Digital Crossover, and 3D effects. The embedded SPoC Configuration Toolbox allows for fast configuration and performance optimization. The CX20705 turnkey solution eliminates the need for a multiple-chip reference design, making it easy and economical for manufacturers to design products for high quality audio applications. A complete evaluation kit with reference board and all the necessary technical documents and software is available. Distinguishing Features • 24-bit DAC/Four ADC, SNR 102 dB, THD 92 dB at 48 kHz 3.3 V • Programmable on-chip proprietary DSP –Digital equalizer (10 bands/ channel) –Dynamic range compression –Digital Crossover –3D Expander (Phantom mode and Immersion mode) • USB 2.0 Compliant Audio Class Interface • One 2-wire I2C or 4-wire SPI slave interface for external MCU • 3-wire digital audio I/O (I2S/PCM/SPDIF), supporting half-duplex receive-only traffic • Stereo 2.5 W BTL Class-D speaker amplifier • Flexible power management • Audio sample rate: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48, 64, 88.2, 96 kHz The SoC is packaged in an environmentally-friendly, RoHS/Green-compliant 76-pin QFN (Quad Flat No leads) package. Applications • 2.1 Channel Smartphone/iPOD docking systems Part Number CX20705 • 2.1 Channel All-in-One PC speaker Description Speakers-on-a-Chip with On-chip Audio DSP, Integrated I2S/I2C/USB Codec, and Class-D Amplifier Audio Speakers-on-a-Chip CX20705 Features CODEC • 3-wire digital audio I/O (I2S/PCM/SPDIF), supporting half- duplex receive-only traffic • One 2-wire I2C or 4-wire SPI slave interface for external MCU • 10-bit ADC multiplexed to support analog volume potentiometer and DC level detection • USB 2.0 Compliant Audio Class interface • Variable master cock rates • Eight GPIO pins DSP • Stereo 2.5 W BTL Class-D speaker amplifier • Digital equalizer (10 bands/channel) • Single-ended or differential stereo analog audio input • Dynamic range compression • Integrated 50 mW headphone driver with jack sense • Digital Crossover • 24-bit DAC/ADC, SNR 102 dB, THD - 92 dB at 48 kHz 3.3 V • 3D Expander (Phantom mode and Immersion mode) • Audio sample rate: 8, 11.025, 12, 16, 22.05, 24, 32, 44.1, 48, 64, 88.2, 96 kHz SPoC Configuration Toolbox • 90 dB dynamic range with 0.01percent THD+N at 4 Ω load • Device configuration and DSP parameter adjustment • Spread Spectrum for filter-less, low EMI output • Output log for convenient MCU programming SE or Diff Line In 3 M SE Line In • Fast configuration tool via USB-to-I2C from PC DSP M SE or Diff Line In • Flexible power management ADC M Memory DMA DAC SE or Diff 600 W or 10 kW line DAC Capless HP Out 32 W DAC Capless HP Out 32 W DMA SE or Diff Line In M SE or Diff Line In 3 M SE Line In 2.5W Class-D DSP ADC Matrix 2 Matrix 1 Matrix 0 GPIO 4 GPIO 3 GPIO 2 GPIO 1 GPIO 0 M 2.5W Class-D SE or Diff 10 kW line SPI I C Slave Volume Voltage Monitor EEPROM DATA TX EEPROM CLK CSN MISO MOS/SDA SCL USB Detect USB+ RX_DAT MON ADC UART 2 RX USB I2S USB- Jack Sense CLK Sense SE or Diff 10 kW line Controller DMA Clock Circuitry RX_WS XTAL In/ Master In XTAL Out CX20705 Interface Diagram The CX20705 is offered in a 76-pin QFN package Conexant Product Portfolio Conexant’s comprehensive product portfolio includes solutions for imaging, audio, embedded modem and video surveillance applications. © 2009 Conexant Systems, Inc. All Rights Reserved. Conexant and the Conexant logo are registered trademarks of Conexant Systems, Inc. All other trademarks are owned by their respective owners. Although Conexant strives for accuracy in all its publications, this material may contain errors or omissions and is subject to change without notice. This material is provided AS IS and without any express or implied warranties, including merchantability, fitness for a particular purpose and non-infringement. Conexant shall not be liable for any special, indirect, incidental or consequential damages as a result of its use. 09-2896 www.conexant.com General Information: U.S. and Canada: (888) 855-4562 International: 1+ (949) 483-3000 Headquarters 4000 MacArthur Blvd. Newport Beach, CA 92660 Doc# PBR-202397