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YB1520 Datasheet, PDF (1/10 Pages) YOBON TECHNOLOGIES,INC. – Step-up DC-DC Converter, White LED Driver
YB1520
Step-up DC-DC Converter, White LED Driver
Description
The YB1520 is a step-up DC-DC converter;
operates as current source to drive up to
18 white LEDs in parallel/series
configuration. Series connecting of the
LEDs provides identical LED currents
resulting in uniform brightness and
eliminating the need for ballast resistors.
The light intensity of these LEDs is
proportional to the current passing through
them. The YB1520 switches at a fixed
frequency of 700KHz, allowing the use of
tiny, low profile inductors and capacitors to
minimize footprint and cost in space
consideration applications for cellular
phone backlighting or other hand held
equipment.
The YB1520 can drive up to 18 white LEDs
from a 4.5V supply. The wide input voltage
range from 2.7V to 7V is ideal for portable
(5V) applications with higher conversion
efficiency. To control LED brightness, the
LED current can be pulsed by applying a
PWM (pulse width modulated) signal with a
frequency range of 100Hz to 50KHz to the
CTRL pin.
YB1520 has integrated Over Voltage
Protection that prevents damage to the
device in case of a high impedance output
due to faulty LED or open circuit caused by
abnormal conditions.
Typical Application Circuit
Features
„ Built-in Internal Switch
„ 2.7V to 7V Input Range
„ <1uA Shutdown Current
„ High Efficiency
„ Drives up to 3S2P to 3S6P White LEDs
(VIN at 3.5V to 5V)
„ Over Voltage Protection 30V
„ Small 5-Lead SOT-23 Package
Applications
„ LCD Display Module
„ White LED Backlighting
„ PDAs, GPS terminals
„ Digital Cameras
„ Cellular Phone
„ Electronic Books
„ Portable Applications
Figure 1: Typical Application Circuit
YB1520 Rev.1.4
www.yobon.com.tw
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