YB1508
Step-up DC-DC Converter , White LED Driver
Description
Features
The YB1508 is a step-up DC-DC converter,
acting as current source to drive up to 8
white LEDs in series. 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. Additional features include output over
voltage protection to prevent device damage
due to faulty LED or open circuit caused by
abnormal conditions, and one-pin shutdown
and multiple methods of dimming control.
The YB1508 switches at a fixed frequency of
1MHz, allowing the use of tiny external
components and low input noise and ripple.
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.
The YB1508 is available in a low profile 5-lead
SOT-23 package.
Typical Application Circuit
2.7V to 9V input range
Adjustable output voltage up to 40V
Built in internal switch
Inherently matched LED current
Fixed frequency of 1MHz PWM
operation
Open LED protection
Low profile 5-Lead SOT-23 package
High efficiency: over 80% at 3.6V
input voltage
Drives up to 8 white LEDs
Applications
LCD Display Module
OLED panel/sub-panel
White LED Backlighting
Digital Camera
Cellular Phone
Portable Application
Figure 1:Typical Application Circuit
YB1508 MRev1.4
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