Audio

Speakers-on-a-Chip

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.

The SoC is packaged in an environmentally-friendly, RoHS/Green-compliant

76-pin QFN (Quad Flat No leads) package.

Applications

•

2.1ChannelSmartphone/iPODdockingsystems

•2.1ChannelAll-in-OnePCspeaker

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

Part Number CX20705

Description

Speakers-on-a-Chip with On-chip

Audio DSP, Integrated I2S/I2C/USB

Codec, and Class-D Amplifier

Speakers-on-a-Chip with On-chip Audio DSP, Integrated

I2S/I2C/USB Codec, and Class-D Amplifier

CX20705