ADC pushes the boundaries for software defined radio

June 11, 2014 // By Jean-Pierre Joosting
At this week’s VLSI circuits symposium 2014 in Honolulu, imec will present a low power pipelined SAR (successive-approximation register) ADC in 28nm digital CMOS with record resolution, speed and power performance.

The ADC targets wireless receivers for next-generation software defined radio, including wireless standards such as LTE-advanced and the emerging generation of Wi-Fi (IEEE802.11ac).

In a software defined radio, the ADC needs high speed, high resolution and high power efficiency in a dynamic solution, supporting high, as well as low bandwidth standards. The pipelined SAR ADC developed by imec and Renesas Electronics achieves an excellent peak SNDR (signal to noise distortion ratio) of 70.7 dB at a speed as high as 200 MS/s while consuming only 2.3 mW at 0.9 V supply voltage. Moreover, the implementation in 28nm digital CMOS not only adds to its area and power efficiency, but also supports digitalization of the radio.

“This novel ADC architecture is an important achievement in imec’s R&D program on future wireless technologies, focusing on the development of highly flexible software-defined radios that support high bandwidth and well as low bandwidth standards,” commented Liesbet Van der Perre, program director wireless technologies at imec. “The architecture is based on prior groundbreaking ADC designs from imec, cleverly exploiting the opportunities of modern advanced CMOS technologies. Scaling toward smaller technology nodes will result in an even better performance of the ADC.”