CURRENT DETECTION CIRCUIT AND DC-DC CONVERTER COMPRISING THE SAME

• Main Author: TAJIMA HIDEYUKI
• Format: Patent
• Language: English; Japanese
• Published: 28.09.2017
• 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; GENERATION

PROBLEM TO BE SOLVED: To provide a current detection circuit capable of suppressing increase in cost of manufacture, and to provide a DC-DC converter comprising the same.SOLUTION: According to an embodiment, a current detection circuit 10 comprises: a transistor MN1 whose source and gate are respectively connected with a source and a gate of a transistor Tr1 provided at a high side of a drive circuit 12; an operational amplifier A1 that amplifies a potential difference between a drain voltage of the transistor Tr1 and a drain voltage of the transistor MN1; and a transistor MN2 provided on a current path in which a current flowing in the transistor MN1 flows, and whose gate is supplied with an output voltage of the operational amplifier A1. A value of a current flowing in the transistor Tr1 is detected from a value of the current flowing in the transistor MN1.SELECTED DRAWING: Figure 1 【課題】製造コストの増大を抑制することが可能な電流検出回路及びそれを備えたＤＣＤＣコンバータを提供すること。【解決手段】一実施の形態によれば、電流検出回路１０は、ソース及びゲートが、駆動回路１２のハイサイド側に設けられたトランジスタＴｒ１のソース及びゲートにそれぞれ接続されたトランジスタＭＮ１と、トランジスタＴｒ１のドレイン電圧とトランジスタＭＮ１のドレイン電圧との電位差を増幅するオペアンプＡ１と、トランジスタＭＮ１に流れる電流が流れる電流経路上に設けられ、ゲートにオペアンプＡ１の出力電圧が供給されるトランジスタＭＮ２と、を備え、トランジスタＭＮ１に流れる電流の値からトランジスタＴｒ１に流れる電流の値が検出される。【選択図】図１