LIGHT EMITTING ELEMENT DRIVING DEVICE

• Main Authors: TAKAGI RYO, AOKI HIROSHI
• Format: Patent
• Language: English; Japanese
• Published: 18.03.2021
• 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; BASIC ELECTRIC ELEMENTS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERATION; SEMICONDUCTOR DEVICES

To suppress overshoot of an output current.SOLUTION: A light emitting element driving device 1 comprises: a slope voltage generation part 15 for generating a slope voltage Vslp containing information about an inductor current IL flowing to a switch output stage (11H, 11L, L1, C2); a sense amplifier 16 that generates a sense voltage Vs corresponding to an output current ILED supplied from the switch output stage to a light emitting element LED; an error amplifier 17 that generates a control voltage Vc corresponding to a difference between the sense voltage Vs and a reference voltage VISET; a comparator 19 that generates a comparison signal SET by comparing the slope voltage Vslp and the control voltage Vc with each other; a controller 13 that controls the switch output stage in accordance with the comparison signal SET; and a clamper 19 that limits the control voltage Vc so as to be equal to or lower than a clamp voltage Vclp corresponding to the slope voltage Vslp.SELECTED DRAWING: Figure 6 【課題】出力電流のオーバーシュートを抑制する。【解決手段】発光素子駆動装置１は、スイッチ出力段（１１Ｈ、１１Ｌ、Ｌ１、Ｃ２）に流れるインダクタ電流ＩＬの情報を含んだスロープ電圧Ｖｓｌｐを生成するスロープ電圧生成部１５と、スイッチ出力段から発光素子ＬＥＤに供給される出力電流ＩＬＥＤに応じたセンス電圧Ｖｓを生成するセンスアンプ１６と、センス電圧Ｖｓと基準電圧ＶＩＳＥＴとの差分に応じた制御電圧Ｖｃを生成するエラーアンプ１７と、スロープ電圧Ｖｓｌｐと制御電圧Ｖｃとを比較して比較信号ＳＥＴを生成するコンパレータ１９と、比較信号ＳＥＴに応じてスイッチ出力段を制御するコントローラ１３と、制御電圧Ｖｃをスロープ電圧Ｖｓｌｐに応じたクランプ電圧Ｖｃｌｐ以下に制限するクランパ１９と、を有する。【選択図】図６