Matching Items (2)
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- All Subjects: Integrated circuits--Defects.
- Genre: Masters Thesis
- Creators: Barnaby, Hugh
- Creators: Peterson, Cory
- Member of: ASU Electronic Theses and Dissertations
Description
Efficiency of components is an ever increasing area of importance to portable applications, where a finite battery means finite operating time. Higher efficiency devices need to be designed that don't compromise on the performance that the consumer has come to expect. Class D amplifiers deliver on the goal of increased efficiency, but at the cost of distortion. Class AB amplifiers have low efficiency, but high linearity. By modulating the supply voltage of a Class AB amplifier to make a Class H amplifier, the efficiency can increase while still maintaining the Class AB level of linearity. A 92dB Power Supply Rejection Ratio (PSRR) Class AB amplifier and a Class H amplifier were designed in a 0.24um process for portable audio applications. Using a multiphase buck converter increased the efficiency of the Class H amplifier while still maintaining a fast response time to respond to audio frequencies. The Class H amplifier had an efficiency above the Class AB amplifier by 5-7% from 5-30mW of output power without affecting the total harmonic distortion (THD) at the design specifications. The Class H amplifier design met all design specifications and showed performance comparable to the designed Class AB amplifier across 1kHz-20kHz and 0.01mW-30mW. The Class H design was able to output 30mW into 16Ohms without any increase in THD. This design shows that Class H amplifiers merit more research into their potential for increasing efficiency of audio amplifiers and that even simple designs can give significant increases in efficiency without compromising linearity.
ContributorsPeterson, Cory (Author) / Bakkaloglu, Bertan (Thesis advisor) / Barnaby, Hugh (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2013
Description
Negative Bias Temperature Instability (NBTI) is commonly seen in p-channel transistors under negative gate voltages at an elevated temperature. The interface traps, oxide traps and NBTI mechanisms are discussed and their effect on circuit degradation and results are discussed. This thesis focuses on developing a model for simulating impact of NBTI effects at circuit level. The model mimics the effects of degradation caused by the defects.
The NBTI model developed in this work is validated and sanity checked by using the simulation data from silvaco and gives excellent results. Furthermore the susceptibility of CMOS circuits such as the CMOS inverter, and a ring oscillator to NBTI is investigated. The results show that the oscillation frequency of a ring oscillator decreases and the SET pulse broadens with the NBTI.
The NBTI model developed in this work is validated and sanity checked by using the simulation data from silvaco and gives excellent results. Furthermore the susceptibility of CMOS circuits such as the CMOS inverter, and a ring oscillator to NBTI is investigated. The results show that the oscillation frequency of a ring oscillator decreases and the SET pulse broadens with the NBTI.
ContributorsPadala, Sudheer (Author) / Barnaby, Hugh (Thesis advisor) / Bakkaloglu, Bertan (Committee member) / Kitchen, Jennifer (Committee member) / Arizona State University (Publisher)
Created2014