The name Wolfson Microelectronics is synonymous with high-quality audio. The company knows A/D and D/A converters. It knows audio codecs. Now the company has introduced a new IC called the WM5100, which it calls the first audio SoC. The WM5100 combines a multichannel analog/digital audio hub—with four analog single-ended or differential stereo pair inputs (eight audio A/D converters with digital microphone interfaces in parallel), three stereo analog outputs, and a pair of 2W class-D headphone output channels (for a total of eight audio D/A converters)—and a DSP complex reportedly consisting of three custom-designed DSPs. As Chief Commercial Officer Andy Brannan told New Electronics, “In the past, our parts were big A, small D. This is more like 50:50.” Here’s the block diagram of the WM5100 audio SoC (highly simplified to fit in this poor blog format):
The DSPs implement a variety of important audio algorithms including sample-rate conversion, 5-band audio equalization, dynamic range control, high- and low-pass filtering, wind noise detection, acoustic echo cancellation, and speech clarification. The device also implements ambient noise cancellation and can take the ambient noise signal from any of its eight analog or digital inputs. The WM5100 audio SoC replaces five audio chips and it is a perfect example of mixed-signal SoC and Silicon Realization in action.
According to Peter Clarke’s article in EETimes, the WM5100, the three DSPs inside of the WM5100 were custom designed by Wolfson. The chip doesn’t push the limits of silicon by any stretch of the imagination. It’s implemented with 180nm process technology. It reportedly has 75 MIPS of processing power in its three DSPs, so you know they’re not clocked at hundreds of MHz and they don’t need to be. This is audio, after all, albeit high-quality audio. The WM5100 runs on 1.8V and costs $6.20 in quantities of 1000. Yet the device replaces five other chips in the space-scavenging world of portable audio products. It’s a sure winner and a great example of using integration to achieve real economic and performance goals.
Wolfson’s WM5100 is also a great example of mixed-signal SoC and Silicon Realization. Wolfson leveraged its significant analog and audio expertise by adding in “big D” digital DSP elements to develop an SoC with a clearly defined application and characteristics that are superior to previous design solutions. What more could any project want?