CURRENT-MODE CONTROL-TYPE SWITCHING POWER SUPPLY DEVICE

• Main Author: YAMAGUCHI YUHEI
• Format: Patent
• Language: English; Japanese
• Published: 07.06.2018
• 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-mode control-type switching power supply device which can feed back a current if the ratio of an output voltage to an input voltage is small.SOLUTION: A switching power supply device 101 includes: an upper MOS transistor Q1 (first switch); a lower MOS transistor Q2 (second switch); a current detection circuit 4 for detecting a current flowing in the second switch; and a control unit for controlling the first and second switches according to a current detected by the current detection circuit 4. The control unit has an error amplifier 2 for amplifying the difference between a voltage according to the output voltage of the switching power supply device 101 and a reference voltage. The control unit controls an off-timing of the first switch by comparing a slope voltage based on a current flowing in the second switch and the output voltage of the error amplifier 2.SELECTED DRAWING: Figure 1 【課題】入力電圧に対する出力電圧の比が小さい場合でも電流帰還が可能な電流モード制御型スイッチング電源装置を提供する。【解決手段】スイッチング電源装置１０１は、上側ＭＯＳトランジスタＱ１（第１スイッチ）と、下側ＭＯＳトランジスタＱ２（第２スイッチ）と、第２スイッチを流れる電流を検出する電流検出回路４と、電流検出回路４によって検出された電流に応じて第１及び第２スイッチを制御する制御部と、を備える。前記制御部は、スイッチング電源装置１０１の出力電圧に応じた電圧と基準電圧との誤差を増幅するエラーアンプ２を備え、第２スイッチを流れる電流に基づいたスロープ電圧と、エラーアンプ２の出力電圧とを比較して第１スイッチのオフタイミングを制御する。【選択図】図１