ACT4533

ACT4533 Rev 1, 25-Feb-13 Wide-Input Sensorless CC/CV Step-Down DC/DC Converter FEATURES 40V Input Voltage Surge 32V Steady State Operation Up to 3A Output Current Constant Current Output with Input up to 32V Output Voltage up to 12V 125kHz Switching Frequency Eases EMI Design Good EMI Performance to Pass EN55022 Radiation Regulation without adding EMI Components 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 0 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 92% Efficiency 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 ACT4533 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. ACT4533 provides up to 3A output current at 125kHz switching frequency. Active CC is a patent-pending control scheme to achieve highest accuracy sensorless constant current control. Active CC eliminates the e...