An 8-bit 3.2GS/s CMOS Time-Interleaved SAR ADC with Non-Buffered Input Demultiplexing

LEANDRO PASSETTI; BENJAMıN T. REYES; MARIO R. HUEDA; AGUSTIN C. GALETTO; FREDY SOLIS; LAURA BIOLATO

Puerto Vallarta

Conferencia; 2018 IEEE 9th Latin American Symposium on Circuits & Systems (LASCAS); 2018

IEEE

Abstract?An 8-bit, 3.2 GS/s, time interleaved (TI) successive approximation register (SAR) analog-to-digital converter (ADC) with a non-buffered hierarchical demultiplexing architecture is proposed and fabricated. Compared to a typical hierarchical TIADC, (i) all track-and-hold (T&H) related noise sources and (ii) wide-band amplifiers for buffering of the input signal are avoided. In this way, the proposed solution can improve the signal-to-noise-ratio and reduce power consumption. The concept is demonstrated in an 8-bit 3.2 GS/s TI-ADC design based on 32 asynchronous SAR ADCs and fabricated in a 0.13μm CMOS process. The prototype includes (i) a programmable delay cell array to adjust four front sampling phases, and (ii) a 25.6 Gb/s low voltage differential signaling (LVDS) interface. Measurements of the fabricated TI-ADC show 44.6 dB of peak signal-to-noise-anddistortion ratio and 105 mW of power consumption at 1.2 V.