Ambiq Micro's SPOT Fetches Lower IoT Power Requirements

Ambiq Micro has a semiconductor solution that it says requires a whole lot less power than competing solutions, and now the company is working to apply that technology to other aspects of the Internet of Things.

The company calls this technology Subthreshold Power Optimized Technology, or SPOT. Thomas Chen, senior director of marketing of Ambiq Micro, explained that typical circuit design runs at 1.8 Volts but that the Ambiq Micro solution runs at or around .5 Volts, which is in the sub-threshold region. Circuits don’t typically work in that region – which is problematic due to susceptibility to noise, high sensitivity to temperature, and variability due to process drift. But the company found a way to make it work by redesigning every analog and digital circuit in the chip to adapt for the temperature, voltage, and manufacturing variations that are problematic at these voltage levels.

“Rather than using transistors that are turned all the way on, subthreshold circuits use the leakage of off transistors to compute in both the digital and analog domains,” according to the company. “With most computations handled by using only leakage current, total system power consumption on the order of nanoamps is easily achieved. For example, when compared to a typical circuit operating at 1.8 volts, a near-threshold circuit operating at 0.5 volts can achieve up to a 13-time improvement in dynamic power. An even more aggressive sub-threshold circuit operating at 0.3 volts can achieve up to a 36 times improvement.”

This solution evolved from research Ambiq Micro’s founder and CTO Scott Hanson did while he was at the University of Michigan. Since opening for business Ambiq Micro has shipped 10 million of the SPOT units. And now the company is applying the technology to connectivity and sensors used in wearables, said Chen.