Cost Effective LED Controller
OB3370N is a high integrated and cost effective
Light Emitting Diode (LED) driver optimized for
LCD monitor and LCD TV backlight application.
The OB3370N operates in voltage mode boost
topology with fixed frequency to regulate the LED
current. The LED current is sensed through an
external current sense resistor. The voltage across
the sensing resistor is compared with reference
level of 200mV, the error is amplified to control the
pulse width of the power switch thus to regulate
the current flowing the LED.
It offers both internal burst and external low
frequency PWM (LPWM) dimming methods for a
wide range of dimming control.
OB3370N integrates under voltage lockout (VCC
UVLO) and output over voltage protections that
prevent the damage in the event of abnormal
conditions. The output voltage level is monitored
through OVP pin and it turns off the converter if an
over voltage condition is present due to an open
The OB3370N is available in SOP-8 Packages.
Voltage Mode PWM Controller
Flexible Dimming Mode Control:
| Internal burst dimming control
| External burst (LPWM) dimming control
0-2V DC voltage direct dimming control
without external circuits
Output Over Voltage Protections
Under Voltage Lockout
Flat panel display
Figure1. OB3370N Typical Application Schematic