{"title":"Light Sensor to Switch On a Light or Any Device","authors":"Saif Aldeen Saad Alkadhim, Sarah Kadhim Aboud","doi":"10.2139/ssrn.3318154","DOIUrl":"https://doi.org/10.2139/ssrn.3318154","url":null,"abstract":"The Light Dependent Resistor (LDR) is made from a Cadmium-Sulfide compound (CdS). CdS is a semiconductor material. The resistance of the LDR changes as the light level changes. More light produces more electron — hole pairs in the material, making the material a better conductor in light. Resistance decreases (conductivity increases) as light levels increase because there are more charge carriers in the material. Note that R = 1/G (G is conductance).<br><br>The LDR controls the voltage on the transistor’s base. As it gets darker in the room, the voltage on the base will increase until the transistor is forward biased. This results in high current flowing from the transistor’s collector to the base. This collector current flows to the LED and is responsible for turning the LED on.","PeriodicalId":185724,"journal":{"name":"EngRN: Semiconductors (Topic)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132944298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingyu Zhu, Yingtao Jiang, Mei Yang, Xiaohang Wang
{"title":"Towards Temperature Insensitive Nanoscale CMOS Circuits with Adaptively Regulated Voltage Power Supplies","authors":"Mingyu Zhu, Yingtao Jiang, Mei Yang, Xiaohang Wang","doi":"10.2139/ssrn.3389126","DOIUrl":"https://doi.org/10.2139/ssrn.3389126","url":null,"abstract":"In this paper, we show that the temperature-induced performance drop seen in nanoscale CMOS circuitscan be tackled by powering the circuits with adaptively regulated voltage power supplies. Essentially, when temperature rises, the supply voltage will be bumped up to offset otherwise performance degradation. To avoid thermal over-drift as chip temperature exceeds its operation range, a voltage limiteris integrated into the proposed power supply to cap the supply voltage. Using this proposed adaptive voltage source to power individual CMOS logic gates and/or subsystems will free the chips from using expensive high-precision temperature sensors for thermal management and performance tuning. Experiments on various benchmark circuits, which are implemented with a 45nm CMOS technology, have confirmed that the circuit delay variation can be reduced to 15%~30% over a wide temperature range (0℃ to 90℃), a sharp contrast to the large delay variations (50%~75%)observed in most IC designs where a constant power supply is employed.","PeriodicalId":185724,"journal":{"name":"EngRN: Semiconductors (Topic)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128521905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}