The CS42L52 is the latest addition to Cirrus Logic's Low Power Audio CODEC family.

The CS42L52 is a highly integrated, low power stereo CODEC with a headphone and Class D speaker amplifier. Building on the success of the current low power converter line, Cirrus Logic has incorporated features such as PWM speaker drivers, an on-board charge pump, and flexible voltage configurations into the CS42L52.

Integrated solutions such as the CS42L52 help to simplify the designer' job of creating a high quality signal path for portable audio devices, while eliminating the need for external components such as regulators for multiple power supplies, buck converters for direct battery connection, and amplifiers for the stereo speaker. Supplementary features such as analog by-pass, Programmable Gain Amplifier (PGA), Automatic Level Control (ALC) on the ADC signal input path, digital signal processing engine as well as a beep generator on the DAC output path allows the system architect to focus on other areas that may need improvement.

Setting the precedent for portable converter integration on our previous generation CODEC with ground centered outputs and an on-board charge pump, the CS42L52 is capitalizing on the previous low power CODEC innovations with the additions of items such as MCLK support for 12, 24, and 27MHz, as well as giving the system architect direct battery connection for the PWM amplifier, with single power supply operation on the remainder of the chip.

This combination of PWM stereo speaker driver, ground centered outputs, and broad MCLK support without a power consuming PLL is unique to the market, and is a key differentiator for the CS42L52.

The ADC input path allows independent channel control of a number of features. Input summing amplifiers mix and select line-level and/or microphone level inputs for each channel. The microphone input path includes a selectable programmable-gain pre-amplifier stage and a low noise MIC bias voltage supply.

A PGA is available for line or microphone inputs and provides analog gain with soft ramp and zero cross transitions. The ADC also features a digital volume control with soft ramp transitions. A programmable ALC and Noise Gate monitor the input signals and adjust the volume levels appropriately. To conserve power, the ADC may be bypassed while still allowing full analog volume control.

The DAC output path includes a digital signal processing engine with various fixed function controls. Tone Control provides bass and treble adjustment of 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 also includes de-emphasis, limiting functions and a BEEP generator delivering tones selectable across a range of two full octaves.

The flexibility, ntegration and performance of the CS42L52 are all packaged in a 40-Pin QFN that delivers 13 mW quiescent power consumption at 1.8 Volts.