ACT4523

ACT4523 Rev 7, 01-Aug-13 Wide-Input Sensorless CC/CV Step-Down DC/DC Converter FEATURES 40V Input Voltage Surge 38V Steady State Operation Up to 3A output current Output Voltage up to 12V Patent Pending Active CC Sensorless Constant Current Control − Integrated Current Control Improves Efficiency, Lowers Cost, and Reduces Component Count Resistor Programmable − Current Limit from 1.5A to 3A − Patented Cable Compensation from 0Ω to 0.3Ω ±7.5% CC Accuracy − Compensation of Input /Output Voltage Change − Temperature Compensation − Independent of inductance and Inductor DCR 2% Feedback Voltage Accuracy Up to 94% Efficiency 225kHz Switching Frequency Eases EMI Design Advanced Feature Set − Integrated Soft Start − Thermal Shutdown − Secondary Cycle-by-Cycle Current Limit − Protection Against Shorted ISET Pin SOP-8EP Package APPLICATIONS Car Charger/ Adaptor Rechargeable Portable Devices General-Purpose CC/CV Supply GENERAL DESCRIPTION ACT4523 is a wide input voltage, high efficiency Active CC step-down DC/DC converter that operates in either CV (Constant Output Voltage) mode or CC (Constant Output Current) mode. ACT4523 provides up to 3A output current at 225kHz switching frequency. Active CC is a patent-pending control scheme to achieve highest accuracy sensorless constant current control. Active CC eliminates the expensive, high accuracy current sense resistor, making it ideal for battery charging applications and adaptors with accurate current lim...