Safer "Listen Through" earbuds create headaches for developers due to increased processing demands

Necessity to cut power driving demand for ultra-low power memory

May 4, 2022 -- One of the joys of earbuds is that they can isolate you into a world of beautiful music with Active Noise Cancelling (ANC) removing the sounds from the world around you. However, some of those sounds can be very important, situational awareness, safety warnings such as a siren, a car horn, a smoke detector or a baby crying. The solution that is increasingly being designed in is called ‘listen through’ or ‘hear through’ where the ANC allows through certain pre-determined sounds to the wearer instead of cancelling them out. The problem with these features is that they require more “always-on” complex processing with the attendant, additional power-hungry memory needs which in turn increases the power consumption. As the form factor for earbuds is constrained so is the battery size limiting the ability to add these new capabilities without compromising the battery life.

Paul Wells, sureCore’s founder and CEO, explained:

“We are signing several new IP licensing deals with earbud manufacturers where they are not selecting just one of our ultra-low power memory technologies but signing for a set of them to really help squeeze the power budget without compromising the performance. This enables them to pack in more powerful features than their rivals without shortening the operational battery life. Our research shows that the extra processing demands of features such as ANC, listen through, voice control, etc. can account for around 50% of the total device power budget with a big proportion of this coming from the memory. Typically, our low power memory solutions can cut dynamic power by half compared to standard offerings. Some customers are going further and are exploiting our low voltage capabilities to drive power down even more. Developers now have to really focus on memory if the end product is going to meet its power budget and be commercially viable.”

sureCore first delivered an SRAM capable of similarly offering a wide operating voltage range over 4 years ago which developers have taken advantage of for identical reasons. In that case, the memory is based on the foundry bit cell with the company’s patented SMART-Assist™ technology ensuring the bit cell is always operated in the foundry recommended voltage window.

The MiniMiser architecture is based on a customised storage element and exploits sureCore’s SRAM power saving techniques to deliver significantly improved power characteristics even at nominal process voltages. The architecture lends itself to several optimisation criteria – multi-port and high-performance variants can be readily generated by the company’s powerful proprietary compiler technology. As MiniMiser is not based on the foundry bit cell then its yield characteristics, like the logic, follow the process d0 thereby easing DFT considerations.

sureCore’s range of ultra-low power memory solutions include Everon™, PowerMiser™, and MiniMiser™. Further details can be found on our Products page. PowerMiser delivers dramatic dynamic power savings at nominal operating voltages whereas Everon and MiniMiser support true near-threshold operation with direct logic connection and single rail design easing both physical and timing design challenges.

Demand for the company’s custom memory design service, sureFIT™, is growing rapidly as developers are realising that to achieve optimal power and performance goals then off-the-shelf memory can no longer give them the edge they need. This is particularly true where complex memory subsystems to support AI, ML and AR applications are needed. By exploiting the company’s system level expertise, coupled with its in-depth memory knowledge, bespoke solutions can be crafted to deliver the requisite combination of Power, Performance and Area (PPA).