TI公司的PCM3070嵌入了miniDSP的立体声音频CODEC,具又可编程的输入和输出,预定和参数化信号处理区块,集成PLL和LDO以及灵活的数字接口. 全编程的miniDSP支持录音和/或播放时的专用算法,立体声音频DAC的SNR为100dB, 立体声音频ADC的SNR为93dB,主要用在条形音箱,平板电视,MP3坞站,手机坞站以及其它立体声或2.1家用音频系统.本文介绍了PCM3070主要特性,方框图, 典型电路配置图以及PCM3070EVM-K评估模块与USB-MODEVM接口块主要特性,模块方框图,电路图和材料清单, 条形音箱参考设计主要特性,电路图, SoundBarProgrammer_RevA和RDK-Value-SB_RevA电路图与材料清单.
Stereo Audio Codec With Embedded miniDSP
The PCM3070 is a flexible stereo audio codec with programmable inputs and outputs,fully-programmable miniDSP, fixed predefined and parameterizable signal processing blocks, integrated PLL, integrated LDOs and flexible digital interfaces.
The PCM3070 features two fully-programmable miniDSP cores that support application-specific algorithms in the record and/or the playback path of the device. The miniDSP cores are fully software controlled. Target algorithms, like speaker EQ, Crossovers, Dynamic Range Controls, Intelligent volume controls and other post-processing algorithms are loaded into the device after power-up.
Extensive register-based control of input/output channel configuration, gains, effects, pin-multiplexing and clocks is included, allowing the device to be precisely targeted to its application.
The record path of the PCM3070 covers operations from 8kHz mono to 192kHz stereo recording, and contains programmable input channel configurations covering single-ended and differential setups, as well as floating or mixed input signals.
The playback path offers signal-processing blocks for filtering and effects, and supports flexible mixing of DAC and analog input signals as well as programmable volume controls. The playback path contains two high-power output drivers as well as two fully-differential outputs. The high-power outputs can be configured in multiple ways, including stereo and mono BTL.
The voltage supply range for the PCM3070 for analog is 1.5V–1.95V, and for digital it is 1.26V–1.95V. To ease system-level design, LDOs are integrated to generate the appropriate analog or digital supply from input voltages ranging from 1.8V to 3.6V. Digital I/O voltages are supported in the range of 1.5V–3.6V.
The required internal clock of the PCM3070 can be derived from multiple sources, including the MCLK pin, the BCLK pin, the GPIO pin or the output of the internal PLL, where the input to the PLL again can be derived from the MCLK pin, the BCLK or GPIO pins. The PLL is highly programmable and can accept available input clocks in the range of 512kHz to 50MHz.

PCM3070主要特性:
• Stereo Audio DAC with 100dB SNR
• Stereo Audio ADC with 93dB SNR
• Extensive Signal Processing Options
• Embedded miniDSP
• Six Single-Ended or 3 Fully-Differential Analog Inputs
• Stereo Headphone Outputs
• Stereo Line Outputs
• Very Low-Noise PGA
• Analog Bypass Mode
• Programmable PLL
• Integrated LDO
• 5mm x 5mm 32-pin QFN Package

PCM3070应用：
• Soundbar
• Flat Panel Television
• MP3 Docking stations
• Cell Phone Docking Stations
• Other Stereo or 2.1 Home Audio systems

图1.PCM3070简化方框图

图2.PCM3070模拟信号流框图

图3.PCM3070典型电路配置图

PCM3070EVM-K评估模块
This evaluation module (EVM) features a complete stereo audio codec with several inputs and outputs, extensive audio routing, mixing, and effects capabilities. The PCM3070EVM is in the Texas Instruments (TI) modular EVM form factor, which allows direct evaluation of the device performance and operating characteristics and eases software development and system prototyping.
The PCM3070EVM-K is a complete evaluation/demonstration kit, which includes a USB-based motherboard called the USB-MODEVM Interface board and evaluation software for use with a PC running the Microsoft Windows operating systems.
The PCM3070EVM-K is operational with one USB cable connection to a PC. The USB connection provides power, control, and streaming audio data to the EVM for reduced setup and configuration. The EVM also allows external control signals, audio data, and power for advanced operation, which allows prototyping and connection to the rest of the development or system evaluation.



图4.PCM3070EVM-K评估模块外形图

PCM3070EVM-K评估模块主要特性:
• Full-featured evaluation board for the PCM3070 stereo audio codec
• USB connection to personal computer (PC) provides power, control, and streaming audio data for easy evaluation
• Onboard microphone for ADC evaluation
• Connection points for external control and digital audio signals for quick connection to other circuits/input devices
The PCM3070EVM-K is a complete evaluation kit, which includes a universal serial bus (USB)-based motherboard and evaluation software for use with a personal computer running the Microsoft Windows™ operating system (Win2000 or XP).


图5.PCM3070EVM-K评估模块方框图

图6.PCM3070EVM-K评估模块电路图(1)

图7.PCM3070EVM-K评估模块电路图(2)
PCM3070EVM-K评估模块材料清单:



图8. USB-MODEVM接口块电路图(1)

图9. USB-MODEVM接口块电路图(2)

图10. USB-MODEVM接口块电路图(3)
USB-MODEVM接口块材料清单:


条形音箱参考设计

Value Sound Bar Reference Design Kit
This is a Value Soundbar reference design kit for Stereo or 2.1 applications, which can easily be reapplied for PC speakers, or MP3 Docks. This is a complete reference design, including all programming hardware required, so you can get to working within minutes, a prototype within hours, and production within 8 weeks on average!
The cost of build of the Value Soundbar Reference Design Kit is 30% less than the discrete solutions available in the market today. The design has a multitude of stuffing options, allowing developers to customise the product easily, without having to redesign the PCB. The software comes in two parts, firstly the MSP430 code (completely open source) and a code file for the home audio version of Purepath Studio.
TI integrates both the programmer for the MSP430 and a dedicated programmer for the PCM3070 and EEPROM.

条形音箱参考设计主要特性:
1x Two Layer FR4 Printed Circuit board and two accessory pcb’s (buttons & LCD’s).
Analog, S/PDIF and USB inputs can be added/removed simply with pick and place BOM options
Optional headers for extra channel outputs (e.g. Extra DAC for line out subwoofer)
Compatible with the CC8520 Evaluation board for wireless Subwoofer transmitter.
Dedicated “programmer” board for in-circuit programming of the EEPROM and real-time modification of running code on the PCM3070
“Programmer” Board design and layout can be reused for production programming with the addition of pogo pins.
Includes SRS WOW HD™ as a standard feature with no additional cost to customers and a near-term roadmap to include TruVolume™ and TruSurround HD™


图11. SoundBarProgrammer_RevA电路图

图12.RDK-Value-SB_RevA电路图(1)

图13.RDK-Value-SB_RevA电路图(2)

图14.RDK-Value-SB_RevA电路图(3)

图15.RDK-Value-SB_RevA电路图(4)

图16.RDK-Value-SB_RevA电路图(5)

图17.RDK-Value-SB_RevA电路图(6)
SoundBarProgrammer_RevA材料清单和RDK-Value-SB_RevA材料清单见: