YB1517
Step-up DC-DC Converter & White LED Driver
Description
The YB1517 is a Current-mode PWM step-up
DC-DC converter. It can drive up to 18V at 3.0V
input and 30V at 5.0V input. The 1 MHz switching
frequency allows it to work with tiny external
components, therefore minimize the footprint and
cost in space consideration products.
One of the major applications for YB1517 is in the dc
to dc converter and OLED power supply and TFT
panel power supply.
When using YB1517 for white LED driving, it is not
recommended to control LED brightness by applying
a PWM signal to the CTRL pin, because the built-in
soft-start circuit might interfere the start-up operation
of YB1517 and cause lower brightness. It operates
as current source to drive up to 5 white LEDs in
series at 3.0V input and up to 8 white LEDs at 5.0V
input. 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.
YB1517 has integrated Latched 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.
Features
•
•
•
•
•
•
•
•
•
•
900 KHz current-mode PWM converter
Built-in internal switch
Adjustable output voltage up to 30V
2.7V to 16V input range
<1uA shutdown current
Internal Soft Start
Drives up to 5 white LEDs
Tiny Inductor and Capacitors allowed
Small 5-Lead SOT-23 package
220mV Low Reference Voltage
Applications
•
•
•
•
•
•
•
LCD Display Module
White LED Backlighting
PDAs, GPS terminals
Digital Cameras
Cellular Phone
Electronic Books
Portable Applications
Typical Application Circuit
YB1517 MRev.1.0
www.yobon.com.tw
1
YOBON [ YOBON TECHNOLOGIES,INC. ]
