February 19, 2014, Seoul - STMicroelectronics (ST), a leading global semiconductor company serving customers across diverse electronic applications, announced the successful demonstration of an ultra-wide-voltage range (UWVR) digital signal processor (DSP) based on 28nm ultra-thin body buried-oxide (UTBB) FD-SOI technology developed with CEA-Leti.

The chip was manufactured by ST using 28nm UTBB fully-depleted silicon-on-insulator (FD-SOI) process technology, allowing body bias voltage scaling from 0V to +2V, lowering the minimum circuit operating voltage, and supporting clock frequency operation from 400mV to 460MHz.

In this demonstration, design methodologies were combined to achieve ultra-wide-voltage range (UWVR), enhanced energy efficiency, and superior voltage and frequency scalability. ST and Leti developed and optimized a standard cell library in the 0.275V - 1.2V range. The results were ideal thanks to the non-overlapping characteristics of power and performance. Among the optimized cells, fast pulse-triggered flip-flops were designed to tolerate variability at low voltages.

Additionally, an on-chip timing margin monitor flexibly adjusts the clock frequency to the maximum operating frequency with very low margin percentage, independent of supply voltage value, body bias voltage value, temperature, and process technology. As a result, this DSP achieves a 10x improvement in maximum operating frequency even at 0.4V.

Philippe Magarshack, Senior Vice President of Design Implementation Services at ST, stated, "UTBB FD-SOI technology is ST's 'Faster, Cooler, Simpler' solution. This technology significantly improves performance and power efficiency while minimizing modifications to existing design and manufacturing approaches. The DSP demonstration shows that FD-SOI technology is setting new standards for better mobile battery products with more efficient semiconductor chips applied down to the 10nm node."

Thierry Collette, Vice President of Leti and Director of Design and Embedded Systems Platforms, explained, "Leti advances technology development to leverage the unique power and performance benefits of advanced design technologies by connecting innovation with industry leadership, thereby contributing to the design of dedicated components best suited for Internet of Things products."

A joint Leti/ST paper titled "A 460MHz at 397mV, 2.6GHz at 1.3V, 32b VLIW DSP, Embedding Fmax Tracking" was presented at Session 27 (Energy-Efficient Digital Circuits) of ISSCC on February 12, and demonstration kits were shown to attendees.