A 14Gb/s high-swing thin-oxide device SST TX in 45nm CMOS SOI

Abstract

The limited supply voltage of today's state-of-the-art CMOS technologies makes the design of high-speed transmitters at signaling swings above the typical 1 V supply a challenging task. Higher-voltage TX amplitude is not only required in older I/O standards and legacy applications, but also in emerging electro-optical extensions where high voltage swing combined with high-speed operation is desired. Higher swing also helps meet certain I/O standards in applications where losses introduced by high-density package constraints can be compensat ed to some extent. The source-series terminated (SST) driver is a versatile building block in a multi standard I/O TX thanks to its potential for low-power operation, its low area consumption, high CMOS-style circuit content, and flexible termination capability. Also, the SST driver supports single-ended output and differential operation. This contribution presents a high-swing SST TX based entirely on thin-oxide devices and using a split supply approach for driving the NMOS and the PMOS branches of the output driver, along with a static voltage protection scheme.