Conexant CX2310x USB广播音视频译码方案

Conexant 公司的CX2310x是USB广播音视频译码器,能通过集成的USB接口在个人电脑上接收模拟和数字广播流,可接收单一模拟流,两个同时接收的数字电视传输流,或模拟和数字编程的组合流. CX2310x支持立体声,单声道,双语(Mono)和三语(Trivox)以及复合视频, S视频, 480i YPrPb, RGB包, YCrCb 包, 10位包和YCrCb/YUY2等视频格式.本文介绍了CX2310x系列(CX23100, CX23101和CX23102)的主要特性, 方框图以及RDE253S/RDU253S USB 混合TV 参考设计框图和主要特性.

USB Broadcast Audio/Video Decoder CX2310x

The CX2310x brings Conexant’s long heritage of audio and video capture solutions to systems that enable univeral serial bus architectures. The family of devices integrates all the functions required to perform television and external A/V capture on personal computers or consumer electronic devices.

The device family includes CX23100, CX23101, and CX23102. The CX2310x decoders enable the capture of analog and digitial broadcast streams on personal computers through an integrated Universial Serial Bus (USB) interface. The devices can capture a single analog stream, two simultaneous digital television transport streams, or a combination of analog and digital programming. In addition, analog, hybrid and combo configurations may be used in conjunction with hardware MPEG encoders.

Highly Integrated

This latest generation of devices integrates anti-aliasing, noise rejection filters and automatic gain control (AGC) and also includes an integrated analog IF demodulator compatible with low IF tuners. Quality video is accomplished by using 10-bit video ADCs, a full 10-bit video data path, and a horizontal and 5-tap vertical scaling, hue, brightness, saturation, and contrast controls.

For high-quality audio, we have analog to digital converters for stereo audio capture and a minimum of 16-bit audio resolution through the entire audio data path which ensures high fidelity audio, whether it comes from the integrated broadcast audio decoder or the ADCs. The audio path includes an automatic volume control function and two assignable stereo processing units for control of volume, three-band equalization, and balance. The level of audio and video integration provided by the CX2310x removes the need for additional broadcast audio decoding and processing chips or external sound demodulation chips. It also reduces the overall bill of materials (BOM) for the system developer, without compromising audio and video performance.

Distinguishing Features

• USB 1.1/2.0 compliant bus

• Advanced consumer IR functionality for controlling set-top boxes

• Demodulator low or high IF for direct IF tuners

• Worldwide audio and video support

• Automatic video and broadcast audio standard detection and configuration

• Flexible video input MUX supporting composite, S-Video, and component inputs with integrated anti-alias filtering

• Integrated sigma-delta stereo audio ADCs with 4:2 MUX

• Audio sample-rate-converters on all inputs and outputs

• Two MPEG transport stream ports: Serial or Parallel interfaces

CX2310x 主要特性:

• Support for the following audio formats: Stereo, Mono, Dual Language (Mono), Tri Language (Trivox)

• Three I2C master ports (Two ports are provided for a two tuner design to isolate I2C transactions to reduce noise.)

• Macrovision 1.0 Detection Compliant

• Support for the following video formats: Composite, S-Video, 480i YPrPb, RGB Packed, YCrCb Packed, 10-bit Packed, and YCrCb/YUY2 Format

• Advanced consumer IR functionality enables systems to receive, learn, and blast IR signals

• High-quality multi-tap horizontal and vertical image scaler for decoded video or 4:2:2 sources

• I2s out

• Auxiliary Phase Locked Loop (PLL) clock for general use

• Integrated analog demodulator compatible with direct IF tuners

• USB 1.1/2.0 compliant bus

• Worldwide audio and video decoding

• Automatic video and broadcast audio standards detection and configuration

• Flexible video input MUX supporting composite, S-Video, and component inputs with integrated anti-alias filtering

• Integrated sigma-delta stereo audio ADCs with 4:2 MUX

• Audio sample rate converters on all inputs and outputs

• Two MPEG transport stream ports: Parallel and Serial

• Two program stream inputs accommodating serial or parallel interfaces

• Programmable VBI data slicer for data services such as closed caption, WSS, and program guides such as Gemstar 1x & 2x

• ITU-R BT.656 output port

图1.CX23102方框图

RDE253S/RDU253S USB 混合TV 参考设计

This reference design enables the capture of analog and digital broadcast streams on personal computers via the USB port. It allows integration of television streaming on small form factor systems such as notebook and netbook PCs as well as desktop systems. With the RDE253S/RDU253S, PC manufacturers and system integrators can add live TV viewing and recording functions to their PC platforms. Key features of this reference design include small form factor and low power consumption, which are particularly important on battery-powered portable notebook consumer solutions.

The integration of the high quality components as well as a single PCB board for either ATSC or DVB-T hybrid solutions set this PC-TV USB hybrid stick ahead of the competition. There are two different designs that can be implemented with a single board, either an NTSC/ATSC hybrid solution (RDU253S) or a PAL/DVB-T hybrid solution (RDE253S).


图2.RDE2535参考设计板

图3.RDU2535参考设计板

Conexant’s CX23102 broadcast audio/visual decoder is capable of capturing a single analog stream, two simultaneous digital television transport streams, or a combination of analog and digital programming on personal computers through the integrated USB interface. Quality video is accomplished by using 10-bit ADCs, a full 10-bit data path and a horizontal and 5-tap vertical scaling, hue, brightness, saturation, and contrast controls. High fidelity audio is achieved with analog to digital converters for stereo audio capture and a minimum of 16-bit audio resolution throughout the audio data path. The decoder also contains an integrated analog IF demodulator compatible with low IF tuners.

Depending on the digital broadcast standard required, digital channel demodulation is handled by Conexant’s standalone CX24228 ATSC digital channel demodulator or CX24232 DVB-T digital channel demodulator.

For the RDU253S solution, digital channel demodulation is supported by Conexant’s CX24228 ATSC digital channel demodulator. It supports reception of ATSC 8-VSB terrestrial broadcasts as well as 64-QAM and 256-QAM digital cable transmissions. This part achieves extremely high performance by employing direct IF sampling, robust synchronization, and effective channel equalization techniques. It contains a 12-bit A/D converter and a PWM (Pulse Width Modulator) generator for AGC (Automatic Gain Control) of incoming IF signals. A host interface with an I2C-compatible bus is also included to control the behavior of the demodulator.

For the RDE253S solution, Conexant’s CX24232 DVB-T digital channel demodulator is used, which supports reception of DVB-T COFDM terrestrial broadcasts. This part achieves extremely high performance by employing direct IF sampling, robust  synchronization, and effective channel equalization techniques. It contains a 10-bit A/D converter and a PWM generator for ACG of incoming IF signals. A host interface with an I2C-compatible bus is also included to control the behavior of the demodulator.

Excellent tuner performance for all major analog and digital broadcast television standards is achieved with the NXP TDA18271 silicon tuner. By integrating most basic tuning components, the TDA18271 reduces power consumption and cuts design cycles,enabling faster time-to-market without sacrificing performance.

The RDE253S/RDU253S USB hybrid solution provides manufacturers a complete cost-effective, low power, high quality solution for enabling a PC-TV solution on notebook and desktop computers.

Benefits

Conexant CX23102

• USB 1.1/2.0 compliant bus interface for easy integration with all PC manufacturers

• Worldwide broadcast audio and video support

• Automatic video and broadcast audio standard detection and configuration

• Support for the following audio formats: Stereo, mono, dual language (mono), tri language (Trivox)

• Integrated analog IF demodulator Conexant CX24228

• Direct 44 MHz IF sampling

• Single SAW (Surface Acoustic Wave) filter

• 12-bit A/D converter for sampling

• Low power consumption Conexant CX24232

• Nordig unified 1.0.2 and DTG compliant

• Support 6, 7 and 8 MHz channel bandwidth

• Co-channel and adjacent channel interference filtering

• Impulsive noise filtering

• Automatic transmission parameter detection

• Excellent Single Frequency Network performance

• Low power consumption NXP 18271 Tuner

• Fully integrated RF tracking filters

• Fully integrated IF selectivity (no need for external SAW filters)

• Alignment-free

• Fully integrated oscillators

• Integrated wideband gain control

图3.RDE2535/RDU2535 USB 混合参考设计方框图

RDU253S主要特性:

• Worldwide analog TV (PAL/NTSC/SECAM) support

• Over the air ATSC high definition broadcast streaming and capture

• Clear QAM over cable for high definition broadcasts

• Meets A/74 ATSC specifications including sensitivity, dynamic range and selectivity requirements thus ensuring the best reception for over the air high definition programming

• Bus powered design

RDE253S主要特性:

• Worldwide analog TV (PAL/NTSC/SECAM) support

• Over the air DVB-T digital broadcast streaming and capture

• Bus powered design