The High-Speed Low-Power Dynamic Comparator

This paper comments on four works for the optimization of comparator design. Today, with the development of integrated circuits, the requirements for comparators about low power, low delay, few offset voltage, and low noise are highly desirable. Specifically, these works made progress in the conventional comparator, which comprises a preamplifier and a latch. They also solved some problems, such as decreasing power and delay. Some works employ a positive feedback cross-coupled pares to provide a larger gain in the preamplifier, use PMOS switch transistors to accelerate the definition phase, or a double-tail architecture to increase the latch regeneration speed. Other work designs a charge pump to improve speed.

Smokers’ Affective Responses to COVID-19-Related Health Warnings on Cigarette Packets: The Influence of Delay Discounting

Introduction The addition of graphic health warnings to cigarette packets can facilitate smoking cessation, primarily through their ability to elicit a negative affective response. Smoking has been linked to COVID-19 mortality, thus making it likely to elicit a strong affective response in smokers. COVID-19-related health warnings (C19HW) may therefore enhance graphic health warnings, when compared to traditional health warnings (THW). Further, because impulsivity influences smoking behaviours, we also examined whether these affective responses were associated with delay discounting. Methods In a between-subjects design, 240 smokers rated the valence and arousal elicited by tobacco packaging that contained either a C19HW or THW (both referring to death). Participants also completed questionnaires to quantify delay discounting and attitudes towards COVID-19 and smoking (eg, health risks, motivation to quit). Results There were no differences between the two health warning types on either valence or arousal, nor any secondary outcome variables. There was, however, a significant interaction between health warning type and delay discounting on arousal ratings. Specifically, in smokers who exhibit low delay discounting, C19HWs elicited significantly greater subjective arousal rating than did THWs, whereas there was no significant effect of health warning type on arousal in smokers who exhibited high delay discounting. Conclusion The results suggest that in smokers who exhibit low impulsivity (but not high impulsivity), C19HWs may be more arousing than THWs. Future work is required to explore the long-term utility of C19HWs, and to identify the specific mechanism by which delay discounting moderates the efficacy of tobacco health warnings. Implications The study is the first to explore the impact of COVID-19-related health warnings on cigarette packaging. The results suggest that COVID-19-related warnings elicit a similar level of negative emotional arousal, relative to traditional warnings. However, COVID-19 warnings, specifically, elicit especially strong emotional responses in less impulsive smokers, who report low delay discounting. Therefore, there is preliminary evidence supporting COVID-19 related warnings for tobacco products to aid smoking cessation. Additionally, there is novel evidence that, for some warnings, high impulsiveness may be a factor in reduced warning efficacy, which may explain poorer cessation success in this population.