Low-power DSP re-defined in 28nm FD-SOI technology:ultra-wide-voltage operation

February 13, 2014 // By Julien Happich
At the International Solid-State Circuits Conference (ISSCC) 2014, CEA-Leti and STMicroelectronics have exhibited an ultra-wide-voltage range (UWVR) digital signal processor based on 28nm ultra-thin body buried-oxide (UTBB) FD-SOI technology.

Fabricated by ST, the technology allows body-bias-voltage scaling from 0V to +2V: it decreases minimum circuit operating voltage and supports a clock frequency up to 460 MHz at less than 0.4V. The two partners presented a paper also describing 2.6 GHz clocking at 1.3V, as well as a demonstration kit.

The demonstrator achieves UWVR (ultra-wide voltage range), greater energy efficiency, and unprecedented trade-offs of voltage and frequency using a combination of design techniques, according to both ST and Leti who developed and optimised standard cell libraries to run over the 0.275-to-1.2V range. Among the optimised cells, fast pulse-triggered flip-flops are designed for variability tolerance at low voltage.

Additionally, on-chip timing-margin monitors dynamically adjust the clock frequency to within a few per cent of the maximum operating frequency, independent of supply-voltage value, body-bias-voltage value, temperature, and process technology.

As a result, even at 0.4V, the DSP exhibits a ten-fold increase in operating frequency compared to state-of-the-art competing solutions, according to both developers. 

“This demonstration DSP shows that FD-SOI is blazing the trail for better portable and battery-powered products, using more efficient semiconductor chips, all the way down to the 10-nm node,” commented Philippe Magarshack, Executive Vice President, Design Enablement Services at STMicroelectronics. 

CEA-Leti;  www.leti.fr

STMicroelectronics; www.st.com

See also;

Considerations for Bulk CMOS to FD-SOI Design Porting

FD-SOI less 'risk' than FinFETs, says SOI body