Novel short-circuit protection technique for DC-DC buck converters

作者：Li, Yajun^*; Lai, Xinquan; Ye, Qiang; Yuan, Bing

来源：IET Circuits Devices & Systems, 2014, 8(2): 90-99.

DOI：10.1049/iet-cds.2013.0187

• CONTINUOUS CONDUCTION MODE
• OUTPUT TRANSFER-FUNCTION
• BOOST CONVERTER
• CURRENT LOOP
• PEAK
• WIDTH
• RECTIFIER
• REGULATOR
• DESIGN
• INPUT

This study presents a novel short-circuit protection technique for DC-DC buck converters. The required short-circuit operating frequency is derived in order to avoid the effect of inherent propagation delay in the controller and power transistors. In this design, the short-circuit switching frequency is approximately 31% of the normal value. Simultaneously, the peak current limit is decreased to about 40% of the normal value to lower the power dissipation when a short-circuit event occurs. Once the fault condition is removed, the converters can automatically return to normal operation smoothly by clamping the soft-start signal using the feedback voltage of the output. A buck converter with the proposed technique has been successfully simulated and verified by a 0.6-mu m CDMOS technology. The simulation results show that the power loss is only 17.1% of the constant current limit during the prolonged short-circuit situation, which significantly enhances the reliability of the chip. Furthermore, the converter is able to achieve smooth self-recovery as soon as the fault status is released.

• 出版日期2014-3
• 单位西安电子科技大学