YB1522
Step-up DC-DC Converter White LED Driver
Description
The YB1522 is a step-up DC-DC converter;
with wide input voltage range from 3V to
16V, which operates as current source to
drive up to 3S7P to 3S10P (V
IN
at 3V to
5V). 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 YB1522
switches at a fixed frequency of ~930KHz,
allowing the use of tiny, low profile
inductors and capacitors to minimize
footprint and cost in space consideration
applications.
The YB1522 can drive up to 3S10P white
LEDs from a single Li-Ion battery. At
automotive (5V/12V) 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 1KHz to the CTRL pin.
YB1522 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
Built-in Internal Switch
3V to 16V Input Range
<1uA Shutdown Current
High Efficiency
Internal Soft Start
Drives up to 3S7P to 3S10P White
LEDs(V
IN
at 3.5V to 5V)
Over Voltage Protection 30V
Small 5-Lead SOT-23 Package
Analog and PWM Dimming Control
100mV Low Reference Voltage
Applications
5” ~ 7” LCD Display Module
White LED Backlighting
Car TV
Handheld and PDA
Electronic Books
Digital Photo Frame
Typical Application Circuit
Figure 1: Typical Application Circuit
YB1522 Rev.1.0
www.yobon.com.tw
1
YOBON [ YOBON TECHNOLOGIES,INC. ]
