Novel chip combines ADC with data compression

Novel chip combines ADC with data compression

Samplify won a 2008 Product of the Year award for its SAM1600 compressing ADC. We recently spoke to Daniel Kreindler (Director of Marketing — Medical & Imaging) about the product’s development.

“Samplify was founded (and funded) on the premise that high-speed signal-processing bottlenecks can be relieved using compression. Ultrasound systems require from 32 to 1,024 A/D converter channels, each operating at 50+ Msamples/s and 12 bits/sample. Samplify compression reduces pin counts, power consumption, and memory requirements for ultrasound, solving a pressing sampled data bandwidth problem in a unique way that no company had ever tried before.

“This device, while initially targeted at ultrasound, will also bring the benefits of compression to wireless and industrial control systems as well. If an application is generating and transporting large amounts of data, compression can help reduce the required bandwidth, just as compression has done in the audio, video and telephony markets.

“The team consisted of experienced analog and digital hardware designers, systems and test engineers, and a technical manager. The founder of Samplify and author of the Samplify compression algorithm is a DSP expert with a long history in compression, dating back to the original Dolby AC-2 audio compression algorithm. The rest of the team was responsible for the design, synthesis, verification, and layout of the IC.

“The biggest design challenge was to provide good isolation between the A/D and the digital compression blocks. Naturally, the ADC block is very sensitive to nearby high-speed digital compression logic, so the teams had to carefully coordinate the placement of clock transitions and I/O pads so that the digital compression logic and I/O were relatively “quiet” during critical ADC sampling periods. Plus, the team was trying to achieve this low-noise at 65 Msamples/s across 16 channels, something no one has successfully done before.”

Daniel Kreindler concluded, “One unexpected outcome from the SAM1600 was that the power consumption was significantly lower than expected, less than 44 mW/channel, allowing it to claim the title of “lowest-power, highest density, ultrasound ADC” on the market. The second pleasant surprise came when several customers in the wireless market used the part in applications for which it wasn’t originally designed.”

Christina Nickolas