Self-Calibrated Knee Voltage Detector With 99.65% High Accuracy for AC Charger System in 0.5 $\mu{\rm m}$ 500 V UHV Process

The self-calibrated knee voltage detector (SC-KVD) for electrical isolation primary side charger applications is proposed. The removal of the feedback network which is used in conventional designs and occupies at least 30 mm2 can save PCB area up to around 11%. Besides, the SC-KVD can dynamically adjust the detection point to improve the accuracy to 99.65% compared to the prior arts. The test chip fabricated in 0.5 μm 500 V UHV process can be powered on directly by the AC source owing to the 500 V ultra-high voltage device. Hence, the battery charger can be made more compact and portable than it was and the battery life can be prolonged and guaranteed.

[1]  T. Suntio.  Average and small-signal modeling of self-oscillating flyback converter with applied switching delay , 2006, IEEE Transactions on Power Electronics.

[2]  Chua-Chin Wang,et al.  A Single-Chip 60-V Bulk Charger for Series Li-Ion Batteries With Smooth Charge-Mode Transition , 2012, IEEE Transactions on Circuits and Systems I: Regular Papers.

[3]  Gabriel A. Rincón-Mora,et al.  Accurate, Compact, and Power-Efficient Li-Ion Battery Charger Circuit , 2006, IEEE Transactions on Circuits and Systems II: Express Briefs.

[4]  Ke-Horng Chen,et al.  Fast charging technique for Li-Ion battery charger , 2008, 2008 15th IEEE International Conference on Electronics, Circuits and Systems.

[5]  Ke-Horng Chen,et al.  A Li-Ion Battery Charger With Smooth Control Circuit and Built-In Resistance Compensator for Achieving Stable and Fast Charging , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[6]  R. Saint-Pierre,et al.  A dynamic voltage-compensation technique for reducing charge time in lithium-ion batteries , 2000, Fifteenth Annual Battery Conference on Applications and Advances (Cat. No.00TH8490).

[7]  Hsiao-Hsing Chou,et al.  An Adaptive Output Current Estimation Circuit for a Primary-Side Controlled LED Driver , 2013, IEEE Transactions on Power Electronics.

[8]  Ke-Horng Chen,et al.  Built-in resistance compensation (BRC) technique for fast charging Li-Ion battery charger , 2008, 2008 IEEE Custom Integrated Circuits Conference.

[9]  Jee-Hoon Jung.  Feed-Forward Compensator of Operating Frequency for APWM HB Flyback Converter , 2012, IEEE Transactions on Power Electronics.

[10]  Dianguo Xu,et al.  Analysis and design of the flyback transformer , 2003, IECON'03. 29th Annual Conference of the IEEE Industrial Electronics Society (IEEE Cat. No.03CH37468).

[11]  Michael Baker,et al.  A 0.18-$ \mu{\hbox {m}}$ Monolithic Li-Ion Battery Charger for Wireless Devices Based on Partial Current Sensing and Adaptive Reference Voltage , 2012, IEEE Journal of Solid-State Circuits.

[12]  Scott Dearborn.  Charging Li-ion Batteries for Maximum Run Times An understanding of battery-charging fundamentals and system requirements enable designers to choose a suitable linear or switch-mode charging topology and optimize battery performance in the application , 2022 .

[13]  Yi-Hwa Liu,et al.  Search for an Optimal Five-Step Charging Pattern for Li-Ion Batteries Using Consecutive Orthogonal Arrays , 2011, IEEE Transactions on Energy Conversion.

[14]  M. Jovanovic,et al.  Adaptive off-time control for variable-frequency, soft-switched flyback converter at light loads , 2002 .

[15]  Milan M. Jovanovic,et al.  Small-signal analysis and control design of isolated power supplies with optocoupler feedback , 2005 .

[16]  Y. Panov,et al.  Small-signal model of variable-frequency flyback converter , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..