CM119 is a highly integrated single-chip USB audio controller specifically designed for VoIP (Voice over Internet Protocol) applications. All important analog modules are embedded in CM119, including dual DAC and headphone driver, ADC, microphone booster, phase-locked loop, voltage regulator, and USB transceiver. Eight GPIO pins can form a 24 key matrix that directly supports keyboard control functions without the need for an MCU. It also supports VoIP applications with buzzer output pins. In addition, audio adjustment can be easily controlled through specific HID compatible volume control pins. Many functions are associated with programmable jumpers or external EEPROMs. Manufacturers can customize unique USB VID/PID as EEPROM for VoIP software certification. In addition, it is possible for each device to store an individual unique phone number through a serial number in an external EEPROM. In addition, CM119 provides I2C interface and advanced functionality for LCM integration with MCU applications. VoIP applications are becoming increasingly popular, and VoIP can provide free or low-cost services that appeal to the world. The experience of providing VoIP is due to the use of PC audio, which is related to the use of ordinary phones and poverty alleviation call quality. The integrated C-Media has a developed CM119 USB controller, which connects an ordinary phone, handheld device, or headphone to a USB port on a computer. C-media OEM manufacturers can quickly launch a series of low-cost and high-quality VoIP products into the market.