CM6523B is a USB 2.0 audio chip builds in 8051 for flexible applications. With internal 2-channel ADC and DAC, S/PDIF in/out interface and USB 2.0 High speed switch makes it suits for different kinds of Docking applications, such as iDevice docking, Android Phone or Tablet/Slate docking device and Netbook/Notebook docking.

CM6523B is compatible with USB audio Class 1.0, thus it can plug & play without additional software installation on the major operation systems. The internal DAC/ADC and S/PDIF out interface support 96K/88.2K/48K/44.1KHz sampling rate and 16/24bit resolution.

CM6523B integrates the Equalizer on both playback and recording paths. With I2S in/out interface, it can connect external DAC to get higher audio quality or external DSP to process the audio data.


USB Compliance

  • USB Spec. Rev.2.0 full-speed mode compatible
  • 3 USB upstream ports for connecting to PC and IPOD at the same time
  • Latest USB Audio Device Class Definition Release 1.0 compatible
  • USB Human Interface Device (HID) Class Definition Release 1.1 compliant
  • Supports USB suspend/resume/reset functions
  • Supports control, interrupt, bulk, and isochronous data transfers

Audio Engine

  • Playback Streams:
    -Default Sample Rates: 8K/11.025K/16K/22.05K/32K/44.1K/48K/88.2K/96K 
    -Supported Bit Length: 16/24 bit
    -DMA supports 2-channel data to DAC/I2S output
    -DMA supports S/PDIF output
  • Capture Streams:
    -Default Sample Rates: 8K/11.025K/16K/22.05K/32K/44.1K/48K/88.2K/96K
    -Supported Bit Length: 16/24 bit
    -DMA supports 2-channel data from ADC/I2S input
    -DMA supports S/PDIF input
    -Digital mixing/routing engine to mix input streams to output streams

Audio I/O

  • 1 pairs I2S or Left-Justified serial audio output interface
  • 1 pairs I2S or Left-Justified serial audio input interface
  • 2 channel Mic in
  • 2 channel digital Mic in
  • 2 channel line in
  • 2 channel line out
  • Built-in 96K/88.2K/48K/44.1KHz and 16/24-bit S/PDIF receiver
  • Built-in 96K/88.2K/48K/44.1KHz and 16/24-bit S/PDIF transmitter

Integrated 8051 Micro-processor

  • Embedded 8051 micro-processor to handle the comment/protocol transactions
  • Connects to an external EEPROM memory for firmware codes
  • HID interrupts can be implemented via firmware codes
  • Provides maximum HW configuration flexibility with firmware code upgrade
  • VID/PID/Product String can be customized via firmware code programming

Control Interface

  • Master I2C control interface for external audio devices or EEPROM access
  • Master SPI control interface for external audio devices or EEPROM access
  • Max. 32 GPIO pins can be configured via firmware programming
  • GPIOs are configured as HID key and LED indicators and IR receiver


  • HW pin for USB Audio Class 1.0 application mode configuration including Speaker/Headset/Docking/Mic
  • HW pin for A-A path enable/disable
  • HW pin for Self-power or Bus-power mode selection
  • HW EQ for both playback and record path
  • HW pin for EQ enable/disable selection
  • HW pin for PID selection
  • Only single 12MHz crystal input is required (embedded PLL function)
  • Single 5V power supply (embedded 5V to 1.8V regulator for digital core, 5V to 3.3V regulator for digital IO, 5V to 3.5V regulator for analog codec)
  • 3.3V digital I/O pads with 5V tolerance
  • Industrial standard LQFP-128 package (14x14 mm)
USB Audio,PCIe audio,USB audio ic,USB sound chip