CS42L55

The CS42L55 is a highly integrated, 24-bit, ultra-low power stereo CODEC that delivers excellent audio performance. Both the ADC and DAC offer many feature suitable for low power portable system applications. The CS42L55 features Cirrus Logic's patent-pending bi-modal Class H headphone amplifier which combines the efficiency of an integrated step-down and inverting charge pump with the linearity and low EMI of a Class AB amplifier. The amplifier delivers a ground-centered output with a large signal swing even at low voltages and eliminates the need for external DC-blocking capacitors.

The analog input path allows independent channel control of a variety of features. The Programmable Gain Amplifier (PGA) provides analog gain with zero cross transitions. The ADC path includes a digital volume attenuator with soft ramp transitions and a programmable ALC and noise gate monitor the input signals and adjust the volume appropriately. An analog passthrough also exists, accommodating a lower noise, lower power analog in to analog out path to the headphone and line amplifiers, bypassing the ADC and DAC.

The DAC output path includes a fixed-function digital signal processing engine. Tone control provides bass and treble adjustment at four selectable corner frequencies. The digital mixer provides independent volume control for both the ADC output and PCM input signal paths, as well as a master volume control. Digital volume controls may be configured to change on soft ramp transitions while the analog controls can be configured to occur on every zero crossing. The DAC path also includes de-emphasis, limiting functions and a beep generator delivering tones selectable across a range of two full octaves.

These features make the CS42L55 the ideal solution for portable applications that require extremely low power consumption in a minimal amount of space.

The CS42L55 is available in a 36-pin QFN package for the Commercial (-40°C to +85°C) grade. The CDB42L55 Customer Demonstration board is also available for device evaluation and implementation suggestions.