Full metadata
Title
Extending efficiency in a DC/DC converter with automatic mode switching from PFM to PWM
Description
Switch mode DC/DC converters are suited for battery powered applications, due to their high efficiency, which help in conserving the battery lifetime. Fixed Frequency PWM based converters, which are generally used for these applications offer good voltage regulation, low ripple and excellent efficiency at high load currents. However at light load currents, fixed frequency PWM converters suffer from poor efficiencies The PFM control offers higher efficiency at light loads at the cost of a higher ripple. The PWM has a poor efficiency at light loads but good voltage ripple characteristics, due to a high switching frequency. To get the best of both control modes, both loops are used together with the control switched from one loop to another based on the load current. Such architectures are referred to as hybrid converters. While transition from PFM to PWM loop can be made by estimating the average load current, transition from PFM to PWM requires voltage or peak current sensing. This theses implements a hysteretic PFM solution for a synchronous buck converter with external MOSFET's, to achieve efficiencies of about 80% at light loads. As the PFM loop operates independently of the PWM loop, a transition circuit for automatically transitioning from PFM to PWM is implemented. The transition circuit is implemented digitally without needing any external voltage or current sensing circuit.
Date Created
2014
Contributors
- Vivek, Parasuram (Author)
- Bakkaloglu, Bertan (Thesis advisor)
- Ogras, Umit Y. (Committee member)
- Song, Hongjiang (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
viii, 51 p. : ill. (some col.)
Language
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.24756
Statement of Responsibility
by Parasuram Vivek
Description Source
Viewed on June 20, 2014
Level of coding
full
Note
Partial requirement for: M.S., Arizona State University, 2014
Note type
thesis
Includes bibliographical references (p. 51)
Note type
bibliography
Field of study: Electrical engineering
System Created
- 2014-06-09 02:05:52
System Modified
- 2021-08-30 01:36:20
- 2 years 6 months ago
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