Abstract
This paper proposes a technique to optimize dynamically the efficiency of hybrid switched capacitor converters, while changing their output voltage/current. Pulse width modulation can be used to change the output current in LED drivers based on hybrid converters. However, changes in duty-cycle cause a reduction in efficiency due to the increasing output resistance of the associated switched capacitor converter. The proposed solution re-configures dynamically the ratio among the flying capacitors and the size of the switches in the power train to minimize the output resistance in different duty-cycle ranges. Transistor level simulations, using 180nm CMOS technology, show the benefits of this technique in a 3:1 Dickson step-down hybrid capacitive LED driver using three duty-cycle optimization regions. A better efficiency and flatter output resistance over a variable conversion ratio was achieved with up to 8% efficiency improvement in this case study, without increasing the area occupied by power switches and flying capacitors.
Original language | English |
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Title of host publication | 2018 IEEE International Symposium on Circuits and Systems, ISCAS 2018 - Proceedings |
Publisher | Institute of Electrical and Electronics Engineers |
Number of pages | 5 |
ISBN (Electronic) | 9781538648810 |
DOIs | |
Publication status | Published - 26 Apr 2018 |
Event | 2018 IEEE International Symposium on Circuits and Systems, ISCAS 2018 - Florence Conference Center, Florence, Italy Duration: 27 May 2018 → 30 May 2018 https://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=8334884 |
Conference
Conference | 2018 IEEE International Symposium on Circuits and Systems, ISCAS 2018 |
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Abbreviated title | ISCAS 2018 |
Country | Italy |
City | Florence |
Period | 27/05/18 → 30/05/18 |
Internet address |
Keywords
- Hybrid Switched Capacitor Converter
- Integrated DC-DC converter
- LED Driver