ACT4523A-001 ACT4523A Rev 0, 25-Jul-13 Wide-Input Sensorless CC/CV Step-Down DC/DC Converter FEATURES APPLICATIONS 40V Input Voltage Surge Car Charger/ Adaptor 36V Steady State Operation Rechargeable Portable Devices Up to 3.5A Output Current General-Purpose CC/CV Supply Output Voltage up to 12V GENERAL DESCRIPTION 250kHz Switching Frequency ACT4523A is a wide input voltage, high efficiency 91% Efficiency (Vout = 5V 3.5A at Vin = 12V) ActiveCC step-down DC/DC converter that operates Patented ActiveCC Sensorless Constant Current in either CV (Constant Output Voltage) mode or CC Control (Constant Output Current) mode. ACT4523A Integrated Current Control Improves provides up to 3.5A output current at 250kHz Efficiency, Lowers Cost, and Reduces switching frequency. Component Count Active CC is a patented control scheme to achieve Resistor Programmable highest accuracy with sensorless constant current Current Limit from 1.5A to 4.0A control. ActiveCC eliminates the expensive, high accuracy current sense resistor, making it ideal for Patented Cable Compensation from 0 to battery charging applications and adaptors with 0.25 accurate current limit. The ACT4523A achieves 6.5% CC Accuracy higher efficiency than traditional constant current Compensation of Input /Output Voltage Change switching regulators by eliminating its associated Temperature Compensation power loss on the sensing resistor. ACT4523A provides OVP pin for output over voltage protection. Independent of inductance and Inductor DCR 2% Feedback Voltage Accuracy Protection features include cycle-by-cycle current Advanced Feature Set limit, thermal shutdown, and frequency foldback at Integrated Soft Start short circuit. The devices are available in a SOP- Thermal Shutdown 8EP package and require very few external devices for operation. Secondary Cycle-by-Cycle Current Limit Protection Against Shorted ISET Pin SOP-8EP Package CC/CV Curve 6.0 V = 12V IN 5.0 4.0 V = 24V IN 3.0 2.0 V = 18V 1.0 IN 0.0 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 Output Current (A) TM Innovative Power - 1 - www.active-semi.com Copyright 2013 Active-Semi, Inc. Output Voltage (V) ACT4523A Rev 0, 25-Jul-13 ORDERING INFORMATION PART NUMBER OPERATION TEMPERATURE RANGE PACKAGE PINS PACKING ACT4523AYH-T -40C to 85C SOP-8EP 8 TAPE & REEL PIN CONFIGURATION PIN DESCRIPTIONS PIN NAME DESCRIPTION High Side Bias Pin. This provides power to the internal high-side MOSFET gate driver. 1 HSB Connect a 22nF capacitor from HSB pin to SW pin. Power Supply Input. Bypass this pin with a 10F ceramic capacitor to GND, placed as 2 IN close to the IC as possible. 3 SW Power Switching Output to External Inductor. Ground. Connect this pin to a large PCB copper area for best heat dissipation. Return 4 GND FB, COMP, and ISET to this GND, and connect this GND to power GND at a single point for best noise immunity. Feedback Input. The voltage at this pin is regulated to 0.808V. Connect to the resistor 5 FB divider between output and GND to set the output voltage. 6 COMP Error Amplifier Output. This pin is used to compensate the converter. 7 OVP OVP input. If the voltage at this pin exceeds 0.8V, the IC shuts down high-side switch. Output Current Setting Pin. Connect a resistor from ISET to GND to program the 8 ISET output current. Heat Dissipation Pad. Connect this exposed pad to large ground copper area with Exposed Pad copper and vias. TM Innovative Power - 2 - www.active-semi.com Copyright 2013 Active-Semi, Inc.