OB3351Fx

GENERAL DESCRIPTION

OB3351Fx is a highly integrated and cost effective Light Emitting Diode (LED) driver optimized for LCD monitor and LCD TV backlighting application. It provides small size solution with high voltage & current dimming MOSFET .

The OB3351Fx 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 internal reference voltage , 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 OB3351Fx offers external low frequency PWM (LPWM) dimming method for a wide range of dimming control.

The OB3351Fx offers comprehensive protection such as LED open protection and LED short protection, power MOSFET over current protection (OCP) and MOS G/D short protection, 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 OB3351Fx is offered in SOP-16 Package.

FEATURES

n Current Mode PWM Controller

n 9V to 35V Input Voltage Range

n Reference voltage setting through PWM duty cycle

n Programmable 100KHz~300KHz Operation Frequency

n Built in 180V power MOSFET

n Burst dimming with PWM input

n LED open protection

n LED short protection

n Over Voltage Protection

n Over Current Protection

n LED cathode short to GND Protection

n Diode & Inductor Short Protection

n Under Voltage Lockout (UVLO)

n Power MOS G/D short protection

n Fault status output

 

APPLICATIONS

n LCD Monitor

n LCD TV

n Flat panel display

 

 

TYPICAL APPLICATION