ACT4501-001 ACT4501 Rev 2, 14-Nov-12 1.25A CC/CV Step-Down DC/DC Converter FEATURES APPLICATIONS 10V-30V Input Voltage Car Charger 40V Transparent Input Voltage Surge Rechargeable Portable Devices Up to 1.25A Constant Output Current General-Purpose CC/CV Power Supply Output Voltage up to 12V Good EMC Performance on Single Layer PCB GENERAL DESCRIPTION Patent Pending ActiveCC Constant Current ACT4501 is a dedicated cost-effective DC-DC Control converter for 5V/1A car charger applications with a Integrated Current Control Improves wide input voltage and high efficiency. The Efficiency, Lowers Cost, and Reduces converter operates in either CV (Constant Output Component Count Voltage) mode or CC (Constant Output Current) mode. ACT4501 provides up to 1.25A output Resistor Programmable Outputs current at 125kHz switching frequency. Current Limit from 500mA to 1250mA Patented cable compensation from DC Cable ActiveCC is a patent-pending control scheme to achieve high accuracy sensorless constant current Compensation from 0 to 0.5 control. ActiveCC eliminates the expensive, high 2% Feedback Voltage Accuracy accuracy current sense resistor, making it ideal for Up to 90% Efficiency battery charging applications and high-brightness 125kHz Switching Frequency Eases EMI Design LED drive for architectural lighting. The ACT4501 achieves higher efficiency than traditional constant Advanced Feature Set current switching regulators by eliminating the Integrated Soft Start sense resistor and its associated power loss. Thermal Shutdown Protection features include cycle-by-cycle current Secondary Cycle-by-Cycle Current Limit limit, thermal shutdown, and frequency foldback at Protection Against Shorted ISET Pin short circuit. The devices are available in a SOP-8 SOP-8 Package package and require very few external devices for operation. Efficiency vs. Load Current 100 90 V = 12V IN 80 V = 16V IN 70 V = 24V IN 60 50 V = 5V OUT 40 1 10 100 1000 10000 Load Current (mA) TM Innovative Power - 1 - www.active-semi.com Copyright 2012 Active-Semi, Inc. Efficiency (%) ACT4501 Rev 2, 14-Nov-12 ORDERING INFORMATION PART NUMBER TEMPERATURE RANGE PACKAGE PINS PACKING ACT4501SH-T -40C to 85C SOP-8 8 TAPE & REEL PIN CONFIGURATION SOP-8 PIN DESCRIPTIONS PIN NAME DESCRIPTION High Voltage Bias Pin. This provides power to the internal high-side MOSFET gate 1 HSB driver. Connect a 10nF 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. Enable Input. EN is pulled up to 5V with a 4A current, and contains a precise 0.8V 7 EN logic threshold. Drive this pin to a logic-high or leave unconnected to enable the IC. Drive to a logic-low to disable the IC and enter shutdown mode. Output Current Setting Pin. Connect a resistor from ISET to GND to program the 8 ISET output current. TM Innovative Power - 2 - www.active-semi.com Copyright 2012 Active-Semi, Inc.