FAN7300

www.fairchildsemi.com LCD Back Light Inverter Drive IC Features High Efficiency Single Stage Power Conversion Wide Input Voltage Range 6V to 25V Back Light Lamp Ballast and Soft Dimming Few External Components Precision Voltage Reference Trimmed to 2% Soft Start PWM and PFM Control Analog, Burst and Mixed Dimming Function Allows All N-Channel MOSFET Drive Double Pulse Suppression Logic Open Lamp Detection Output Short Circuit Protection Open Lamp Regulation 20 Pin SSOP FAN7300 Description The FAN7300 provides all the control functions for a series parallel resonant converter and also contains a pulse width modulation (PWM) controller to develop a supply voltage. Typical operating frequency range is between 30kHz and 100kHz depending on the CCFL and the transformer's characteristics. 20-SSOP Rev. 1.0.0 ©2003 Fairchild Semiconductor Corporation FAN7300 Internal Block Diagram VZ 3V V3 Vz 8V UVLO Internal Bias 1.5Vref COMP6 SCP + ENA 5.4V R S Q 2uA COMP7 + OLP 3.7V 3V Vm2 VS + Vz 1.5V Multiplier Gain K 8uA S_S Va EA_IN + + Clock E/A Controller EA_OUT Main Control Oscillator Rt OLR COMP3 + 3V COMP2 Va min. 0.25V min. 0.25V - COMP1 R Q Q High side gate driver CPUMP Vmo Error Amp. + Vm1 Buffer S max. 1.75V Current Generator max. 1.75V Vb COMP4 + DIM 2 + Analog Burst Mixed COMP5 - Dimming control and Mode Selection 1.5V DIM_MODE 1.5V 3V Vz Low side gate driver + V3 Vcc + 3.7V OUT_H OUT_L GND Ct BCt 50K 50K F...