OVERCURRENT PROTECTION CIRCUIT AND SWITCHING POWER SUPPLY EMPLOYING THE SAME

• Main Authors: KAWADA SHINJI, ITOHARA KEITA
• Format: Patent
• Language: English; Japanese
• Published: 16.05.2016
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

PROBLEM TO BE SOLVED: To perform an appropriate overcurrent protection operation.SOLUTION: An overcurrent protection circuit 13 comprises: a voltage monitoring part (comparator 131) for monitoring an output voltage VOUT produced by a cyclic switching operation of a switching output stage 11 or a feedback voltage VFB corresponding to the output voltage; a current monitoring part (a comparator 132 and a sense resistor 133) for monitoring whether a monitoring object current IS flowing in the switching output stage 11 is in an overcurrent state; and a protection operation part (a signal delay part 134 and signal path switching parts 135a and 135b) for performing the overcurrent protection operation corresponding to detection results (detection signals DET1 and DET2) of both the voltage monitoring part and the current monitoring part.SELECTED DRAWING: Figure 1 【課題】適切な過電流保護動作を行う。【解決手段】過電流保護回路１３は、スイッチング出力段１１の周期的なスイッチング動作によって生成される出力電圧ＶＯＵＴまたはこれに応じた帰還電圧ＶＦＢを監視する電圧監視部（コンパレータ１３１）と、スイッチング出力段１１に流れる監視対象電流ＩＳが過電流状態であるか否かを監視する電流監視部（コンパレータ１３２、及び、センス抵抗１３３）と、電圧監視部及び電流監視部双方の検出結果（検出信号ＤＥＴ１及びＤＥＴ２）に応じた過電流保護動作を行う保護動作部（信号遅延部１３４、並びに、信号経路切替部１３５ａ及び１３５ｂ）と、を有する。【選択図】図１