BL8549 Datasheet | BELLING

40V Backlight LED Driver with PWM Direct Dimming DESCRIPTION The BL8549 is a high efficiency current-mode asynchronous, 40V boost converter for LED backlight driving. Its input voltage ranges from 2.5V to 4.5V and it provides an adjustable constant current output decided by the Rset connected to BL8549’s FB pin. The LED brightness can also be controlled by a PWM signal directly set to CE pin, making dimming control very simple. The BL8549’s switching frequency is set to 600KHz, and it will automatically switch between PFM and PWM mode based on the load current, thus to enhance the converter efficiency at light load as well as heavy load. BL8549 consists of many protection blocks such as UVLO, output voltage over voltage protection, and thermal protection to keep the chip and load safe under unexpected environment. The BL8549 is available in the tiny DFN2x2-6 and SOT23-6 package. Features - Adjustable Output Voltage, Vfb=0.2V - Output voltage 40V, driving up to 12 LED string - Range of operation input voltage: 2.5 - 4.5V - Output Overvoltage Protection @40V - CE pin PWM direct dimming function - Line regulation: 0.1%/V (typ.) - Load regulation: 10m V (typ.) - High efficiency, up to 90% in driving 10 LEDs - Environment Temperature: -20C~85C APPLICATIONS - Smartphone - 7” MID - Portable DVD - TFT LCD bias - Portable LED lighting or torch - Other application need high voltage TYPICAL APPLICATION and PIN OUT Efficiency for Driving 10 LEDs Efficiency VS Iout for 10 LEDs Efficiency (%) 60 Vin=3.6V 55 50...