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
Current Mode PWM Controller
9V to 35V Input Voltage Range
Reference voltage setting through PWM duty cycle
Programmable 100KHz~300KHz Operation Frequency
Built in 180V power MOSFET
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)
Power MOS G/D short protection
Fault status output
APPLICATIONS
LCD Monitor
LCD TV
Flat panel display