A split transconductor high-speed SAR ADC

A feasibility study of an 8-bit fast converter is presented. The advantages and limits of conventional SAR architectures are discussed and, on the basis of that, a possible optimal architecture is proposed. It uses a 4+4-bit scheme with combination of the DAC outputs in the current domain at the input of the latch. The circuit has been implemented with a 28 nm FDSOI CMOS technology. Post layout simulation results show 8bit of resolution at 1.2 GS/s.