Cirrus Logic has expanded its portfolio of low-power audio converter integrated circuits (ICs) for portable applications, introducing the 24-bit CS43L22 low-power stereo digital-to-analogue converter (DAC) with integrated Class D speaker amplifiers and stereo headphone drivers.The CS43L22 uses advanced low power circuit design techniques to minimise power consumption without sacrificing audio performance. Combined with high levels of integration, the CS43L22 maximises battery life and saves overall system costs by eliminating the need for numerous external components.
Providing up to one watt-per-channel of highly efficient Class D amplification to external speakers and enough power to drive 44 milliwatts per channel into stereo headphones, this portable audio DAC also offers the flexibility to run its core from a single power supply and directly connect the Class-D amplifier to the battery supply for a more efficient operation. This combination of flexible features makes the CS43L22 a suitable audio DAC for portable consumer electronics applications such as portable media players, gaming devices, battery powered docking stations and portable navigation devices.
The CS43L22 builds upon the design techniques of Cirrus Logic's low-power audio products by creating its own on-chip negative power supply voltage. With its ground-centered outputs, the CS43L22 helps reduce clicks and pops during start up, improves low-end frequency response, and eliminates costly, space-consuming DC blocking capacitors. Its stereo Class-D speaker amplifier with "filterless" outputs eliminates the need for external filter components, minimising board space requirements and implementation cost. The DAC also features enhanced master clock support, which includes standard audio frequencies, as well as USB and video clocks. This limits the number of clocks in a system, providing designers a flexible, low-power solution.
Among its features, the CS42L22 provides a digital signal processing engine, digital volume control, headphone/speaker detection switch, as well as flexible signal routing that includes an analogue bypass mode. The integrated Class-D speaker driver also features the ability to directly connect to the battery supply and then simultaneously monitor that supply and compensate for any decay in the voltage. With a dynamic range of 98 dB, the CS43L22 delivers high-performance audio output with low noise, all in an integrated solution that offers flexibility and reduced overall system cost.
The CS43L22 utilises a 40-pin QFN package and consumes only 13 milliwatts of power at 1.8 volts in playback mode while driving stereo headphones. The CS43L22 is currently in volume production.
