CX20745 I2S Audio Codec SoC with Capless Headphone, Digital Microphone and Integrated Stereo Class-D Amplifier
Low-power, cost-effective single-chip solution enables superior audio
The CX20745 is one of Conexant's Speakerson-a-Chip (SPoC) embedded audio solutions specifically designed for compact consumer electronics such as mobile Internet devices, smartbooks, and Web tablets. The lowpower, energy-efficient device features a proprietary inline configurable Digital Signal Processing (DSP), Codec, stereo filter-less Class-D amplifier with Spread Spectrum Electromagnetic Interference (EMI) dispersion technology, capless headphone driver, and I2S interface in a cost-effective single-chip package. The DSP runs a suite of turnkey audio post-processing effects for enhanced sound quality. The SPoC features high performance multibit DACs for speaker output, multi-bit high performance ADCs supporting mono or array microphones and up to three stereo line inputs, capless headphone output, and a range of digital and analog input/output channel selections for flexible routing and mixing. The CX20745 contains a pair of ProCousticTM headphone drivers supporting a full-range frequency response 98 dB dynamic range, and headset jack support, which lowers Bill of Materials (BOM) cost by eliminating the need for external jack sense, external amplifier, and Direct Current (DC)-blocking capacitors. The codec supports four conductor-type Open Mobile Terminal Platform (OMTP) headset jacks with bias sensing for external headset control. All output ports feature Conexant's PopShield DC cancellation to eliminate audio pops and clicks that often occur during power state transitions. The CX20745's power-efficient and flexible Class-D amplifier drives 2 W into a 4 speaker with 5 V supply 1 W with 3.3 V supply. The SPoC operates mA in standby mode and mA in sleep mode, which enhances battery-operated devices through low power consumption and low heat generation. The device supports industrial temperatures Audio of -40~85C. Speakers-on-a-Chip The DSP runs a suite of 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. The fully configurable hardware Equalizer, Dynamic Range Control, and Microphone Automatic Gain Control improves performance, maximizes output volume, protects the speakers, and enables far-field audio pick-up by broadening the sound-capture radius for enhanced audio quality. The CX20745 also features Hardware Digital Volume Control, a feature similar to an infinite volume control knob commonly found in high-end audio-visual equipment. The CX20745 turnkey solution eliminates the need for a multiple-chip reference design and includes Conexant's software driver and design support making it easy and economical for manufacturers to design products for high quality audio applications. The SoC is packaged in an environmentallyfriendly, RoHS/Green-compliant 48-pin QFN (Quad Flat No-leads) package.
· Consumer Electronics Embedded Audio· Mobile Internet Device· Web Tablet Device· Smartbook
FIlterless, low EMI, and power-efficient speaker amplifier with ample power to drive to 2W/ch Audio enhancement and optimization for speakers and microphones High performance audio fidelity with low external interference Pop and Click suppression and cancellation <2.2.mA stand-by (Idle) mode or <.5mA sleep mode
On-chip Digital Signal Processing Multi-bit DACs/ADCs with fully differential internal signaling PopShield with DC offset cancellation Low power stand-by and sleep
Part Number CX20745 Description I2S Audio Codec SoC with Capless Headphone, Digital Microphone and Integrated Stereo Class-D Amplifier
· Stereo 8/16/24-bit DAC supports sample rates capable of and 96 kHz, depending on the master clock 98 dB Dynamic Range -85 dB THD· Stereo 8/16/24-bit ADC supports sample rates capable of and 96 kHz, depending on the master clock· Supports master clock of 24.576 MHz and 22.5792 MHz· Data interface: I2S that can be converted to PCM, I2S/PCM are slave only· Control Interface: I2C slave only· Audio ports: Stereo Analog Input port supporting up to two single-ended microphones (stereo), one differential microphone (mono), two single-ended line-In (stereo), or one differential line-in (mono)
OMTP headset set jack compliant with integrated in-line command sensing. Mic bias sensing capability for external headset control. Supports auto sense and switching between MIC and GND pins Stereo class-D amplifier Stereo capless headphone port Single-ended analog line output (stereo) Digital microphone input (stereo)· Class-D amplifier with the following modes of operation: 2 W per channel into 4 with 5 V supply 1 W per channel into 4 with 3.3 V supply Spread Spectrum for EMI protection on the class-D amplifier· Line-In loopback mode, where the input signal will loop back to the DAC for playback with EQ· PopShield active anti-pop circuit· Device can operate in both 5 V modes· Integrated LDO converting 3.3 V, and 1.8 V
· PDM digital MIC interface supporting clock frequency of 3.072 MHz and 1.536 MHz· Supports industrial temperatures of -40~85C· Jack sense supporting up to four jacks· Codec provides independent gain and mute control for both DAC and ADC· Four General purpose GPIOs GPIO1 and GPIO2 can be configured for "Infinity Volume Control" using a rotary encoder DSP· Digital parametric equalizer (5 bands/ channel)· Dynamic range control including compressor and limiter· Microphone automatic gain control Power Management· Idle Mode: 2.2 mA with 200 ms fast resume· Sleep Mode: 0.5 mA (digital supply only) with 400 ms resume
The CX20745 is offered a 48-pin QFN package Conexant Product Portfolio Conexant's comprehensive product portfolio includes solutions for imaging, audio, video surveillance, and embedded modem applications.
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