ELM900x Datasheet | ELM

DESCRIPTION ELM900x is a CMOS IC designed for driving white LEDs by one or two dry cell as a power source. ELM900x can drive two series white LED by 1.5V-3.0V input voltage. ELM900x uses an external inductor as a voltage booster. ELM900x consists of an oscillator circuit and a driving transistor. The input DC power is transformed to a 35k Hz constant current pulse, when the external inductor switched on and off in 35k Hz. In a standard application inductor is needed as external parts. .. 䂓 FEATURES 䊶Low cost and simple application circuit 䊶High efficiency 䊶Constant average power control 䊶Low noise 35k Hz constant frequency switching 䊶pact SOT-89 package 䂓 APPLICATION 䊶White LED flashlight 䊶Laser pointer 䊶 High VF LED driver 䊶 LCD backlighting 䂓 PIN CONFIGURATION Pin No. Pin Name 1 VSS 2 VDD 3 LX 㪊 SOT-89 㪈 㪉 ( TOP VIEW ) 䂓 MARKING 㪪㪦㪫㪄㪏㪐 㽲 㪃 㽳 : Represents the product IC code 㽲 㽳 90 㽴 : Represents the assembly lot number 0 䌾 9 repeated 㽴 㽵 㽵 : Represents the assembly lot number A 䌾 Z repeated ( I,O,X excepted ) 䂓 MARKING Symbol 㩷㩷㪘㩷㪑 㪪㫅㪆㪧㪹㩷㫇㪸㪺㫂㪸㪾㪼 './Z 㫏 㪧㫉㫆㪻㫌㪺㫋㩷㪭㪼㫉㫊㫀㫆㫅 㩷㩷㪙㩷㪑 㪧㪹㩷㪄㩷㪝㫉㪼㪼㩷㫇㪸㪺㫂㪸㪾㪼 WHITE LED FLASHLIGHT DRIVER ELM900x 䂓 BLOCK DIAGRAM 0EJ&TKXGT .. 8&& 1%5 .: 䂓 APPLICATION CIRCUIT 2 cell 2LED Ǵ-...