YB1315 Schematic ( PDF Datasheet ) - YOBON TECHNOLOGIES

Teilenummer	YB1315
Beschreibung	High Efficiency Charge Pump White LED Driver
Hersteller	YOBON TECHNOLOGIES
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Gesamt 10 Seiten Preliminary YB1315 High Efficiency Charge Pump White LED Driver Description The YB1315 charge pump is designed to drive up to 5 white LEDs with regulated constant current in backlight display application. The device can provide up to 25mA per LED for a total 5 channels. The output current can also be combined into one single channel with 125mA output current for flash-light applications. The input voltage ranges from 2.7V to 5.5V and is ideal for applications powered by a single Li-Ion or 3 to 4 NiCd, NiMH or Alkaline batteries. YB1315 monitors the power-supply input voltage and LED forward voltage and current, and does an automatic selection to a switching mode that is optimized for the power conversion efficiency as well as battery operating time. The 1MHz fixed frequency switching allows for tiny external components, and the regulation scheme is optimized to ensure low EMI and low input ripple. Internal soft-start circuitry effectively reduces the in-rush current. YB1315 also provides short circuit protection, over-temperature protection and over-voltage protection. In shutdown mode, the shutdown current is less than 1μA. YB1315 is available in a TQFN-16 3x3 package. Features „ Voltage Input Range From 2.7V to 5.5V „ Drives From 3 to 5 LEDs at Up to 25mA Each „ Fractional Conversion Modes for High Conversion Efficiency, 1x and 1.5x „ 1MHz Internal Oscillator „ Thermal Protection Shutdown „ Output Short-circuit Current Limit and Over-Voltage Protection „ Under-Voltage Lockout with Hysteresis „ Automatic Soft-Start Reduces In-Rush Current „ 3mm x 3mm TQFN Package Applications „ White LED Backlighting „ Handheld PCs and PDAs „ Mobile Phone „ DSC and DV flash light application Typical Application Circuit VIN = 2.7V to 5.5V 1µF 0. 47µF 0. 47µF VIN VOUT C1+ D1 C1- D2 C2+ D3 YB1315 C2- D4 EN1 D5 EN2 GND ISET PGND 1uF YB1315 Rev.0.1 Figure 1: Typical Application Circuit www.yobon.com.tw 1 Preliminary YB1315 High Efficiency Charge Pump White LED Driver Function Block PGND VOUT 78 C1+ 10 C1- 11 C2+ 9 C2- 12 VIN 13 1x/1.5x Charge Pump Current Sinks 2 D5 3 D4 4 D3 5 D2 6 D1 Reference EN1 15 EN2 16 UVLO Control 14 GND OVP 1 ISET Figure 3: Function Block Functional Description The YB1315 uses a multi-mode fractional charge pump to generate a supply voltage and a precise sink circuitry to ensure a constant driving current for each LED. The charge pump operates in either 1x mode, or 1.5x mode, depending on the input voltage and output current loading. The overall power consumption is best optimized by automatically switching among the 2 different operation mode. The charge pump is possible to generate a total output current of 125mA or more, 25mA for each LED. But it is recommended to operate the device under total 120mA. YB1315 Rev.0.1 www.yobon.com.tw 6 6 Page
Seiten	Gesamt 10 Seiten
PDF Download	[ YB1315 Schematic.PDF ]

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Besondere Datenblatt

Teilenummer	Beschreibung	Hersteller
YB1313	Charge Pump	Yobon
YB1315	High Efficiency Charge Pump White LED Driver	YOBON TECHNOLOGIES
YB1316	Step-Up/ Step-Down / Fixed Output Application	YOBON TECHNOLOGIES

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