A 7.5-GS/s 3.8-ENOB 52-mW flash ADC with clock duty cycle control in 65nm CMOS

A 7.5-GS/s 4.5-bit analog-to-digital converter (ADC) in 65nm CMOS is presented. A two-stage track-and-hold (TAH) with clock duty cycle control reduces bandwidth requirements on the slow TAH output to enable high sampling rates with low power consumption. The 7.5-GS/s flash ADC consumes 52-mW and occupies 0.01-mm2. Clock duty cycle control improves ENOB from 3.5 to 3.8 with an input sinusoid at the Nyquist frequency.