Reliability and Power Supply Scaling Effects on Nanoscale Comparators for Future Flash/SAR Analog to Digital Converter (ADC) Applications

The most of mixed-signal applications, including ADC and DLDO (digital low drop-out regulators), depend on the dynamic comparators. Therefore, enhancing the performance & reliability of dynamic comparators is critical to improve the efficiency of the systems to which they are associated. In this work, we implemented a 3-bit Flash ADC using a high performance cascode cross-coupled dynamic comparator with 16 nm CMOS process and a $\mathrm{V}_{\mathrm{DD}}$ of 0.7 V. First we investigated the thermal reliability and $\mathrm{V}_{\mathrm{DD}}$ scaling effects on the performance of cross-coupled cascode dynamic comparator. The comparator operated with a $\mathrm{V}_{\mathrm{DD}}$ of 0.7 V demonstrated a delay & power consumption of $15.45 \mathrm{pS} \ \& \ 12.77 \ \mu \mathrm{W}$ under $27^{\circ} \mathrm{C}$ and a $\Delta \mathrm{Vin}=\operatorname{VinP}-\mathrm{VinN}$ of 0.7 V. At $107^{\circ} \mathrm{C}$, the comparator shown a delay & power consumption of 24.13 pS & $11.48 \ \mu \mathrm{W}$ at same $\Delta$ Vin. However, when $\Delta$ Vin is reduced to 0.1 V, the comparator demonstrated a delay & power consumption of $\mathbf{1 8. 2 3} \ \mathrm{pS} \ \& \ 14.05 \ \mu \mathrm{W}$ at $27^{\circ} \mathrm{C}$ and 30.16 $\mathrm{pS} \ \& \ 12 \ \mu \mathrm{W}$ at $107^{\circ} \mathrm{C}$. The same comparator when operated with a $\mathrm{V}_{\mathrm{DD}}$ of 1.2 V demonstrated a delay & power consumption of $9.689 \ \mathrm{pS} \ \& \ 101 \ \mu \mathrm{W}$ under $27^{\circ} \mathrm{C}$ and a $\Delta \mathrm{Vin}$ of 1.2 V. At $107^{\circ} \mathrm{C}$, the comparator shown a delay & power consumption of $14.5 \ \mathrm{pS} \ \& \ 84.86 \ \mu \mathrm{W}$ at same $\Delta \mathrm{Vin}$. However, when $\Delta \mathrm{Vin}$ is reduced to 0.1 V, the comparator demonstrated a delay & power consumption of $12.29 \ \mathrm{pS} \ \& \ 112.3 \ \mu \mathrm{W}$ at $27^{\circ} \mathrm{C}$ and $21.66 \ \mathrm{pS} \ \& \ 93.6 \ \mu \mathrm{W}$ at $107^{\circ} \mathrm{C}$.