GENERAL DESCRIPTION

OB3351 is a highly integrated and cost effective Light Emitting Diode (LED) driver optimized for LCD monitor and LCD TV backlighting application. It provides a high performance LED backlight solution with minimized BOM count.

The OB3351 contains a PWM boost driver which uses current mode control and fixed frequency operation to regulate the LED current. The operation frequency can be programmed by setting external resistor value at RI pin. The LED current is sensed through an external current sense resistor. The voltage across the sensing resistor is compared with the reference voltage at REF pin, the error is amplified to control the pulse width of the power switch thus to regulate the current flowing the LED. The reference is set by internal reference voltage and the PWM duty cycle at ISET pin.

The OB3351 offers external low frequency PWM (LPWM) dimming method for a wide range of dimming control.

The OB3351 offers comprehensive protection such as LED open protection and LED short protection, power MOSFET over current protection (OCP), output over voltage protection (OVP), the cathode of LED short to GND protection, Diode & Inductor short protection, IC power supply under voltage lockout (UVLO).

The OB3351 is offered in SOP-14 Package.

FEATURES

Current Mode PWM Controller

9V to 35V Input Voltage Range

Reference voltage setting through PWM duty cycle

Programmable 100KHz~300KHz Operation Frequency

Burst dimming with PWM input

LED open protection

LED short protection

Over Voltage Protection

Over Current Protection

LED cathode short to GND Protection

Diode & Inductor Short Protection

Under Voltage Lockout (UVLO)

APPLICATIONS

LCD Monitor

LCD TV

Flat panel display

TYPICAL APPLICATION