Archive notice: This article was originally published on October 29, 2008. Links and embedded videos are preserved as part of the historical record.
With power consumption of just 5.1 mW when idle during playback and the use of special, patent-pending bimodal Class H technology, the 24-bit CS42L55 reduces power consumption by almost 50 percent compared with the Class A/B amplifiers previously used in portable products. This innovation helps extend battery life, providing up to two additional hours at standard audio sampling rates with headphones connected under real-world playback conditions, while maintaining consistently high audio quality. Measuring just 5 x 5 mm, the CS42L55 is extremely compact, and at only 0.45 mm high it is one of the thinnest portable audio codecs currently available.
“No other portable audio codec currently in production offers the same combination of performance, feature integration, battery life and compact size as the CS42L55,” said Jason Rhode, President and Chief Executive Officer of Cirrus Logic. “This IC clearly demonstrates why Cirrus Logic is the new technology innovator in low-power audio products. Because customers value our innovations, we will continue to capture a significant share of the portable-audio-product market.”
The CS42L55 offers bimodal Class H technology with automatic voltage adjustment for driving headphones and an innovative charge-pump architecture with ground-centered outputs. These technologies form the innovative basis of Cirrus Logic’s portable-audio product portfolio, enabling the codecs to operate with extremely low power consumption and EMI performance far below customary industry limits.
Based on advanced 24-bit multibit delta-sigma technology, the CS42L55 operates from a single 1.8 V or 2.5 V power supply and can deliver an output voltage of 1 V RMS from a 1.8 V supply. When driving headphones from the same supply voltage, the device can deliver a high-quality audio output of 17 mW per channel with a 96 dB dynamic range. The CS42L55 also includes a 2:1 stereo input multiplexer and a USB master-clock input and supports sampling rates up to 48 kHz. Further CS42L55 features include analog volume control to improve performance and reduce the noise floor. Pseudo-differential outputs allow signal routing while reducing noise coupling in analog signals.