Exploration and Evaluation of Low-Dropout Linear Voltage Regulator with FinFET, TFET and Hybrid TFET-FinFET Implementations

• Main Authors: Chang, Chia-Ning, 張珈寧
• Other Authors: Chuang, Ching-Te
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/88x5h8

碩士 === 國立交通大學 === 電子研究所 === 106 === This thesis focuses on analog low-dropout linear voltage regulator and digitally controlled linear voltage regulator with FinFET, TFET and Hybrid TFET-FinFET implementations. We use Sentaurus atomistic 3D TCAD mixed-mode to analysis fundamental physical characteristics of transistors. Also, Verilog-A look-up table calibrated with simulation results from TCAD is applied in HSPICE circuit simulation tool for further analysis. In exploration of analog low-dropout linear voltage regulator (LDO), because the transport mechanism of TFET is different from conventional MOSFET and FinFET, we do investigation of transconductance, output resistance and intrinsic gain of devices at first. It can be observed that, TFET demonstrates better performance at low operating voltage, while FinFET exhibits outperformance in current drive ability which is an advantage in high-performance applications. Furthermore, the performance of FinFET-LDO, TFET-LDO and Hybrid-LDO including frequency response, transient response and power supply rejection ration (PSRR) are evaluated. The results indicate that for ultra-low power application, TFET-LDO and Hybrid-LDO provide better loop-gain and PSRR than FinFET-LDO under comparable operating current design. As operating voltage further reduced, the performance of analog LDO degrades severely; therefore, digitally controlled linear voltage regulator becomes the choice. Firstly, we analyze the digital error detector (DED) based on FinFET and TFET at 0.5V operating voltage. The sense period of TFET-DED is 7x times longer than FinFET-DED. Next step, we investigate the performance of pull/push devices under FinFET, Hybrid and Parallel structures based on FinFET-DED. The results demonstrate FinFET applied in digitally controlled voltage regulator stands out at 0.5V operating voltage due to the relatively strong current drive ability.