US team claims ADC chip is world’s most efficient

A new ADC microchip designed at Brigham Young University in the US is claimed to be the world’s most power-efficient of its type.

ADC
(Credit: BYU Photo)

ADC (analogue-to-digital converter) microchips change analogue inputs into digital signals are in virtually all types of electronic device we use today. Smartphone manufacturers like Apple and Samsung are constantly searching for improved ADC chips that can deliver high performance, but as efficiently as possible so that battery life can be maintained.

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The new BYU-developed ADC chip consumes just 21 milli-Watts of power at 10GHz for ultra-wideband wireless communications. According to the university’s Professor Wood Chiang, existing ADCs consume hundreds of milli-Watts or even Watts of power at comparable speeds.

“Many research groups worldwide focus on ADCs; it’s like a competition of who can build the world’s fastest and most fuel-efficient car,” said Chiang, a professor a BYU’s Department of Electrical and Computer Engineering. “It is very difficult to beat everyone else around the world, but we managed to do just that.”

The team achieved these efficiency gains by focusing on the DAC (digital-to-analogue converter) component of the chip. They were able to increase performance by reducing the loading from the DAC through scaling both the capacitor parallel plate area and spacing. They also grouped unit capacitors in a different way from usual, placing together unit capacitors that are part of the same bit in the DAC rather than having them interspersed throughout. According to the researchers, this lowered the bottom-plate parasitic capacitance by a factor of three, significantly lowering power consumption while at the same time increasing speed.

Finally, they also used a dual path bootstrapped switch where each path can be independently optimised. This method increases the speed but doesn’t require additional hardware because it involves splitting existing devices and making route changes in the circuit. The work is published in IEEE Journal of Solid-State Circuits.

“We’ve proven the technology of the chip here at BYU and there is no question about the efficacy of this particular technique,” Chiang said. “This work really pushes the envelope of what’s possible and will result in a lot of conveniences for consumers. Your Wi-Fi will continue to get better because of this technology, you’ll have faster upload and download speeds and you can watch 4K or even 8K with little to no lag while maintaining battery life.”