EUP2471 ds2471 ver1.1 jul. 2011 1 1.5a dual wled flash driver with i 2 c compatible interface description the EUP2471 is a 2mhz fixed frequency, current mode synchronous boost converter. the device is designed to operate as a dual 750ma (1.5a total) constant curre nt driver for flash white led application. an industry-standard i 2 c serial digital input is used to enable, disable and set the movie-mode current for each flash led with up to 16 movie-mode settings. the EUP2471 also includes a separate flash enable input to initiate both the flash operation and the default t imer, which can be used either to terminate a flash event at the end of a user-programmed delay or as a safety featu re. the maximum flash and movie-mode current is set by one external resistor; the ratio of flash to movie- mode current is set at approximately 6.1:1. an over-voltage protection feature keeps the output voltage below the ovp threshold in case of an open led and an output short circuit protection limits the o utput current during an output short to gnd. the chips quiescent current is less than 1.0 a in shutdown mode. typical application circuit featues 2.7v to 5.5v input supply range dual channel output with separate flash enable up to 1.5a regulated output current (750ma per channel) up to 85% efficiency 2 mhz fixed switching frequency i 2 c compliant serial interface - 400khz serial transfer rate -16 level movie-mode current -flash/movie-mode -programmable led current -programmable flash safety timer true load disconnect input current limit output over-voltage, short circuit, and over-temperature protection 3mm 3mm tdfn-14 package rohs compliant and 100% lead (pb)-free halogen-free applications camera-enabled cellular phones and smart phones digital still cameras (dscs) led photo flash/torch figure 1. EUP2471 two flash leds typical applicatio n
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