Wolfson Microelectronics introduced the WM8510 mono CODEC, its first product designed for Voice over Internet Protocol (VoIP) devices and digital telephones. The WM8510 includes a driver for a speaker or headset, two separate microphone inputs (e.g. handset and speakerphone) and two dedicated analogue audio outputs with volume control. Advanced sigma delta converters are used along with digital decimation and interpolation filters to give high quality audio at sample rates from 8 to 48ks/s. Additional digital filtering options are available in the ADC path, as is an advanced automatic level control (ALC) function with noise gate. An on-chip PLL is provided to generate the required master clock from an external reference clock. The PLL clock can also be output if required elsewhere in the system. The WM8510 has a standard audio interface supporting transmission of audio data to and from the chip. The interface supports a number of audio data formats including μ-law and α-law, PCM, I2S, and DSP Mode, and can operate in master or slave modes. The chip operates at supply voltages from 2.5 to 3.6V, although the digital core can operate at voltages down to 1.62V to save power. The speaker and mono outputs use a separate supply of up to 5V, which enables increased output power if required. Different sections of the chip can also be powered down under software control by way of the selectable two or three wire control interface. The WM8510 is available in a 28-pin SSOP package