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专利名称：Boost controller capable of step-up ratio
control
发明人：Isao Yamamoto,Kyoichiro Araki,Noboru
Kagemoto
申请号：US11083516申请日：20050318公开号：US07307385B2公开日：20071211
专利附图：
摘要：A charge pump circuit boosts a voltage of a battery so as to generate a drivevoltage for an LED. A constant current circuit generates a constant current to feed
through the LED. A monitoring circuit monitors a cathode potential of the LED, i.e., avoltage across the constant current circuit. A control circuit receives a result of
monitoring from the monitoring circuit and increases a step-up ratio of the charge pumpcircuit when the voltage across the constant current circuit drops below a minimumvoltage that guarantees a constant current. The control circuit sets an externallyrequested constant current value in the constant current circuit. When a change from alarge current to a small current is requested, the control circuit returns the step-up ratioof the charge pump circuit to 1.0.
申请人：Isao Yamamoto,Kyoichiro Araki,Noboru Kagemoto
地址：Kyoto JP,Kyoto JP,Kanagawa JP
国籍：JP,JP,JP
代理机构：Cantor Colburn LLP
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