The invention provides a driving method and circuit of a constant-current LED lamp string, in the charging process of charging a G pole of an MOS tube to enable the MOS tube to be conducted, the voltage Vgs of the G pole of the MOS tube is increased, when the voltage Vgs is larger than a first voltage Vth, current begins to flow between a D pole and an S pole of the MOS tube, then the voltage Vgs enters a Miller platform when the voltage Vgs is increased to a second voltage Vplateau, at the moment, the voltage Vgs is kept unchanged, and the voltage Vgs is not changed when the current begins to flow between the D pole and the S pole of the MOS tube. According to the embodiment of the invention, the MOS tube is completely switched on until the voltage Vgs continues to rise, and the generated overcharge current is inversely proportional to T2 during the period from the switch-on of the MOS tube to the complete switch-on, that is, the voltage Vgs is greater than the first voltage and less than or equal to the second voltage period T2. Therefore, the time from the start of conduction to complete conduction of the MOS tube is prolonged, and the overcharge current is reduced.
本申请提供一种恒流LED灯串的驱动方法及电路,对MOS管的G极充电使MOS管导通的充电过程中,MOS管的G极电压Vgs升高,当电压Vgs大于第一电压Vth时,MOS管的D极和S极之间开始流过电流,之后,电压Vgs升高到第二电压Vplateau时进入米勒平台,此时电压Vgs保持不变,直到电压Vgs继续升高时MOS管完全导通,在MOS管开始导通到完全导通期间,即电压Vgs大于第一电压且小于或等于第二电压期间T2,产生的过充电流与T2成反比,本实施例中在T2期间,利用平均电流值较小的脉冲电流对MOS管的G极充电,以延长MOS管开始导通到完全导通的时间,从而减小了过充电流。
Driving method and circuit of constant-current LED lamp string
一种恒流LED灯串的驱动方法及电路
31.05.2024
Patent
Elektronische Ressource
Chinesisch
IPC: | H05B ELECTRIC HEATING , Elektrische Heizung / B60Q ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL , Anordnung von Signal- oder Beleuchtungsvorrichtungen, deren Einbau oder Halterung oder deren Schaltkreise bei Fahrzeugen allgemein |
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