CM6308 C-Media Electronics, Inc., CM6308 Datasheet - Page 5

• Manufacturer Part Number: CM6308
• Description: Cm6308 Usb Audio Chip Specification
• Manufacturer: C-Media Electronics, Inc.

1. Description and Overview
Date: 09/04/2007
The C-Media CM6308 provides an ideal solution for USB headphone, handset, and display
phone products, as well as other PC audio and instant messaging applications. It is a highly
integrated chip with a wide range of USB audio and telecom voice control capabilities. The
CM6308 combines the audio controller and codec, and also integrates I2C and SPI interfaces,
for interfacing with external MCU, LCM or DSP chips. Furthermore, the manufacturer string,
product string, serial number, product ID, vendor ID, and initial playback and recording volumes
can all be customized by interfacing with an external EEPROM.
Instant messaging and VoIP software are gaining widespread popularity, as they provide
real-time audio/video communication in a cost-effective manner. C-Media not only provides the
single chip hardware solution for audio peripherals, but also software middleware that
enhances instant messaging programs.
All essential analog and digital modules are embedded in the CM6308, including a stereo DAC
and stereo ADC, headphone/speaker driving capability, Dynamic Range Compression, Linear
microphone gain control, PLL, regulator, USB transceiver, 12 MHz crystal, and power on reset
circuit. The CM6308 supports sampling rates of 8KHz, 16Khz, 44.1KHz and 48KHz, with high
quailty 16 bit resolution.
Vendors can use the 12 GPIO pins to create a 36 key matrix scan for keypad control functions,
saving additional componment cost. Many features are programmable with the external
EEPROM and MCU interfaces. Furthemore, MCU/EEPROM/GPIO can easily be controlled
through the HID software interface. The buzzer output pin can be easily controlled and
changed through software for different frequencies and patterns. In addition, audio adjustments
can be made through HID volume control pins. 3 LED indicator pins are supported, to provide
more flexible status reporting (On / Off / Operation / playback mute / recording mute) and
controllable flash times (using PWM).
Applications：
High end USB headphone set
USB interface hub, integrated with multi-media audio features
USB handset for VOIP and IM applications
USB display phone for VOIP and Instant Messaging applications
Proprietary USB wireless audio speakers or headphone set
Versatile USB audio accessories (adapter, ducking system integration, etc.)
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Audio and Voice Applications
Single-Chip USB Solution for
Version: 1.91
CM6308