Details CM6642 USB

CM6642 USB Computer External Sound Card Heaphone Amplifier

CM6642 USB Computer

Size: 774 (length * width * height, including knob part) CM

Use a safe and reliable USB Type B port
Plug and play is suitable for most operating systems such as Windows 2000
WIN7, WN8.WIN10.MAC and other operating systems do not need drivers. Note: If there is no sound output after connecting to the computer, please go to the computer control panel-sound setting option and set it as the default.

CM6642 USB best
CM6642 USB best

D4 sound card adopts CM6642 USB audio decoding chip, supports 24Bit192kHz output, and the sound quality is lossless output. It is directly connected to the computer with a USB cable, plug and play.

D4 can be connected to various power amplifiers or active speakers with RCA output, and can also be used as an amp to connect various headphones.

The headphone amplifier part uses 5532 chips, the sound field depth is strong, transparent, bright and durable.

Amplifier rated power output: 150MW+150MW
Amp impedance: 16-350 ohms
Distortion: THD+N: 0.004% (RL>10k9)
Distortion: THD+N: 0.020% (RL=329)
Signal to noise ratio: >99dB
Dynamic range: >99dB

Introduction and Overview product

The CM6642 USB is a low power single chip USB 2.0 High-Speed audio codec built-in MCU for flexible applications. With integrated PWM LED driver and 3-channel ADC/ 2-channel DAC and S/PDIF interface that makes it suitable for headset, headphone, docking, speakers, and microphone applications.

The internal MCU can also be developed to a lot of different applications, such as VoIP device, Mobile Phone or Tablet/Slate docking device. The CM6642 is compatible with USB Audio Class 1.0/2.0 and USB 2.0 High-Speed, thus it can plug & play without any additional software installation on major operating systems. The internal DAC support from 44.1~192 KHz and ADC support from44.1~192 KHz sampling rate with 16/24 bits resolution.

The CM6642 USB also integrates 16K Byte OTP and crystal and just requires few passive components to make a finish product. Thus, it can save the total BOM cost and PCB area can be smaller.

CM6642 USB
CM6642 USB

USB Compliance
USB 1.1/2.0 Full-Speed and High-Speed compliant
USB Audio Class 1.0 and 2.0 compliant
USB Human Interface Device (HID) Class 1.1 compliant
Supports USB suspend/resume/reset functions
Support Selective Suspend mode
Integrated Micro Controller Unit Microprocessor
Embedded MCU micro-processor to handle the command/protocol transactions
Embedded 16K Byte OTP
4K Byte RAM for firmware extension and plug-in
HID interrupts/buttons/functions can be implemented via firmware codes
Provides maximum hardware configured flexibility with firmware code upgrade
VID/PID/Product String can program by firmware

Control Interface
12 GPIO pins and firmware programmable
GPIOs are configured as HID key and LED indicators
PWM LED Driver

Crystal-less (embedded crystal function)
Single 5V power supply (embedded 5V to 1.8V regulator for digital core, 5V to 1.8/3.3V regulator for digital IO, 5V to 1.8V regulator for analog codec)
1.8/3.3V digital I/O pads with 5V tolerance
Industrial standard QFN-48 package (5×6.5mm)
Audio I/O

View front of CM6642 USB best
View front of CM6642 USB best

Playback Stream:

  1. Sample Rates: 44.1K/48K/96K/192KHz
  2. Supports Bit Length: 16/24bits
  3. DAC Gain Range is -65.6 ~ 0dB - S/PDIF transmitter
  4. Sample Rates: 44.1K/48K/96K/192KHz
  5. Supports Bit Length: 16/24 bits

Recording Stream:
– Microphone

  1. Sample Rates: 44.1K/48K/96K/192KHz
  2. Supports Bit Length: 16/24 bits
  3. ADC gain range is -33.5 ~ 30dB - A-A path Stream:
  4. Line In to playback A-A path
  5. Mix Line input to stereo playback both L/R channel
  6. The Line In A-A path gain range is -34.5 ~ 12dB

I think CM6642 USB is a new compact alternative for 6631, even if you need one more SPDIF receiver IC to get finally I2S. Tiny CM6642 QFN-48 5x6mm + WM8804 SSOT-20 + 12MHz Xtall requires about 45% of the PCB area where was implemented 6631 based USB audio interface i.e. CM6631A+Pm39LV512 + 49.152MHz 3.3V low jitter OSC + 45.184MHz 3.3V low jitter OSC + 12MHz Xtall. Furthermore, WM8804 with an average Xtall probably outperforms CM6631A regarding jitter, the BOM cost will be also 20% less. For instance, I migrated from 6641 to 6642+WM8804 and got more than enough PCB area to implement CC2540 BLE controller on the same PCB size(see attached screenshots) and within the same BOM cost


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