IC Pair Drives Superior PC Audio Experience

PC and laptop audio performance is enhanced by this IC set that also delivers output power, low THD, and other benefits.

Bill Schweber

Related To:

Electronic Design

July 19, 2023

3 min read

Audio Laptop Dreamstime L 8447714 64b8421378fa3

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.

About the Author

Bill Schweber

Contributing Editor

Bill Schweber is an electronics engineer who has written three textbooks on electronic communications systems, as well as hundreds of technical articles, opinion columns, and product features. In past roles, he worked as a technical website manager for multiple topic-specific sites for EE Times, as well as both the Executive Editor and Analog Editor at EDN.

At Analog Devices Inc., Bill was in marketing communications (public relations). As a result, he has been on both sides of the technical PR function, presenting company products, stories, and messages to the media and also as the recipient of these.

Prior to the MarCom role at Analog, Bill was associate editor of their respected technical journal and worked in their product marketing and applications engineering groups. Before those roles, he was at Instron Corp., doing hands-on analog- and power-circuit design and systems integration for materials-testing machine controls.

Bill has an MSEE (Univ. of Mass) and BSEE (Columbia Univ.), is a Registered Professional Engineer, and holds an Advanced Class amateur radio license. He has also planned, written, and presented online courses on a variety of engineering topics, including MOSFET basics, ADC selection, and driving LEDs.