A vehicle lamp driver circuit (10 in Fig. 1) for a LED array (11) includes a first LED string (12) in series with a second LED string (14). A LED driver (16) drives the first LED string and a second LED driver (18) drives the second LED string. In a STOP mode of operation, the current to both LED strings is controlled by the LED driver in series with the LED string. In a TAIL mode of operation, the current is provided to only one LED string. When there is reduced input voltage, operation of the LED strings is provided by switching circuits (20, 22) that short-out one LED in each LED string. Another vehicle lamp driver circuit (50 in Fig. 2) includes a first LED string (51) and a second LED string (52) in series with a control switch (56) having a feedback circuit (58) for maintaining constant current regulation to control the sum of the current in each LED string and reduce switching noise.
DRIVER CIRCUIT FOR LED VEHICLE LAMP
CIRCUIT D'ATTAQUE POUR FEU DE VEHICULE A DEL
2016-02-23
Patent
Electronic Resource
English
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 / H01L Halbleiterbauelemente , SEMICONDUCTOR DEVICES |
VEHICLE LAMP, LIGHTING CIRCUIT THEREFOR, DRIVER CIRCUIT, AND DRIVER-INTEGRATED LIGHT SOURCE
European Patent Office | 2019
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