IC Pair Drives Superior PC Audio Experience

The PC-based audio world is not resting on its significant accomplishments of enhancing audio performance in challenging settings such as laptop PCs and other devices. This includes development of better sound (admittedly, this can be hard to define), lower operating power, higher efficiency, and other desirable attributes.

Proof of this is a two-IC audio solution from Cirrus Logic optimized specifically for PCs. It enables a louder, more immersive audio experience, whether listening to voice calls and music from the small internal speakers on ultra-thin laptops or from headphones.

Compared to a basic amplifier signal chain, the CS35L56 smart amplifier hosts the processing power needed to deliver higher-performing audio. Meanwhile, the low-power CS42L43 SmartHIFI PC audio codec integrates a MIPI SoundWire interface (v1.2) to ease transition to that standard (Fig. 1).

1. PC- and especially notebook-based audio performance is greatly improved by this IC pair, which goes far beyond being just a basic amplifier due to its array of smart features, functions, and interfaces.

This advanced audio solution also simplifies design for PC manufacturers and contributes to a reduction in the total number of components to save board space and lower bill-of-material costs. It combines hardware, firmware, and a Windows driver solution, making it compatible across industry-leading processors and with any number of speakers.

2. Basic specifications of the CS42L43 PC audio codec include 192-kHz, 24-bit support with 114-dB DNR and −93-dB THD+N.

The CS42L43 PC audio codec delivers superior voice clarity, wide dynamic range, and low distortion. It helps OEMs deliver more transparent, consistent premium audio quality across headphones offered by OEMs or those chosen by users (Fig. 2).

The codec features 114-dB headphone DNR (dynamic range) and −93-dB THD+N, leveraging its 8- to 192-kHz, 24-bit support. The 70-ball WLCSP package is designed for a standard (non-HDI) PCB with a 13-mm² footprint CSP package and a total 52-mm² functional area (an 88-pin QFN package is also available). Power consumption is about 50% less than competitive units.

3. The associated CS35L56 smart amplifier is more than just a power amplifier: It adds a DSP, sensing hardware, battery-voltage boost for notebooks, and protection and enhancement algorithms.

The companion CS35L56 smart amplifier delivers rich audio with deeper bass, balanced sound,and dynamic range from compact, multi-speaker designs on the thinnest of laptops. It includes an onboard DSP, sensing hardware, notebook battery voltage boost, and protection and enhancement algorithms to deliver industry-leading PC audio that maximizes loudness and increases quality and consistency while minimizing rattle and vibration (Fig. 3).

The 18.5-V Class-D amplifier delivers more than 20 W of audio at 10% THD+N into 4 Ω, and includes 15-V Class-H dc-dc boost. In addition to the SoundWire interface, it provides I²S, I²C, and SPI connectivity. It’s housed in a 34-pin/0.4-mm-pitch QFN package measuring just 4 × 4.5 mm.

Samples of both products are available now with production volumes expected to begin before the end of this year.