AFSEMI AF2039
NMOSFET
FEATURES
l Min1.6V Startup @1mA Load l 600mV Feedback Voltage l 550KHz Internal Oscillator l Soft Startup: 10mS Typical l Peak Current Programmable by Bottom Sensing Resistor l 300µA Typical Iq l Internal PWM/PFM Auto Mode Switching l Up to 90% Efficiency l External Enable l Power OFF Current<1µA l Over Voltage Protection l 140℃ Thermal Shut Down, 20℃ HysteresisAPPLICATIONS
l USB ChargerGENERAL DESCRIPTION
The AF2039 using the external NMOSFET. It is a high efficiency boost converter with 600mV feedback voltage. A switching frequency of 550KHz minimizes solution footprint by allowing the use of tiny low profile inductors and ceramic capacitors. The current mode PWM/PFM design is internally compensated, and the device has a 1.6V startup voltage with 1mA load. It needs few external components, only inductance, resistance and capacitance can meet the driving capacity. Block Diagram AF-V1.0 1/5 Analog Future Pin Assignment Pin 1 2 3 4 5 Symbol FB VDD CE