Nanopower Oscillators with Temperature Compensation

Autor: Yu-Hsuan Chiang, 江侑軒
Rok vydání: 2014
Druh dokumentu: 學位論文 ; thesis
Popis: 102
This thesis consists of two parts. The first part aims to design a submicrowatts and low temperature coefficient (TC) relaxation oscillator. In this oscillator, the transistors in the subthreshold region, the current-mode comparator, and the current-starving inverters are used to reduce the power of the relaxation oscillator. The current-starving inverters are biased by using the PTAT and CTAT current sources to release the temperature variations. The parallel/series composite resistor and the PTAT/CTAT current sources are also used to further reduce the temperature coefficient. The average temperature coefficient is 64.3ppm/°C for the temperature of -20~80°C, and the calculated power FOM is 0.78nW/kHz. The second part implements the low TC current reference and curvature current source with different gate-oxide thickness mosfets to realize the oscillators with low TCs. Two oscillators of 1.4MHz and 28kHz are fabricated in a 0.18-μm CMOS process. For the 1.4MHz oscillator, its power is 615nW with a supply voltage of 1.2V. The measured average TC is 56.4ppm/°C for the temperature of -20~80°C. The calculated FOM1 and FOM2 are 124dB and 103dB, respectively. For the 28kHz oscillator, its power is 40.2nW with a supply voltage of 1.2V. The measured average TC is 95.5ppm/°C for the temperature of -20~80°C. The calculated FOM1 and FOM2 are 119dB and 92dB, respectively.
Databáze: Networked Digital Library of Theses & Dissertations