RP507K001B 600mA Step-down DC/DC Converter with Synchronous Rectifier NO.EA-305-180529 OUTLINE ( 1 ) The RP507K001B is a CMOS-based 600mA step-down DC/DC converter with synchronous rectifier. Internally, a single converter consists of an oscillator, a reference voltage unit, an error amplifier, a switching control circuit, a soft-start circuit, an under voltage lockout (UVLO) circuit, an over current protection circuit, a thermal shutdown circuit and switching transistors. Replacing diodes with built-in switching transistors improves the efficiency of rectification. Therefore, by simply using an inductor, resistors and capacitors as the external components, a low ripple high efficiency synchronous rectifier step-down DC/DC converter can be easily configured. The RP507K001B has an over current protection circuit which supervises the inductor peak current in each switching cycle, and turns the high-side driver off if the current exceeds the Lx current limit. The RP507K001B also contains a thermal shutdown circuit which detects overheating of the converter and stops the converter operation to protect it from damage if the junction temperature exceeds the specified temperature. The RP507K001B is PWM/VFM auto switching control in which mode automatically switches from PWM mode to high-efficiency VFM mode in low output current. The RP507K001B is available in DFN(PLP)1616-6D package which achieves high-density mounting on boards. For an input capacitor (C ) and an output capacitor (C ), the smaller sized 0402/1005 (inch/ mm) capacitor IN OUT can be used. Output voltage is adjustable with external divider resistors. FEATURES Input Voltage Range ............................................. 2.3V to 5.5V (Absolute maximum rating: 6.5V) Output Voltage Range .............................. 0.7V to 5.5V (Note: As for 1.0V or less, input voltage range is limited.) Feedback Voltage Accuracy ................................ 9mV (VFB=0.6V) Temperature-Drift Coefficient of Feedback Voltage .............................................................................. Typ. 100ppm/C Oscillator Frequency ............................................. Typ. 2.0MHz Maximum Duty Cycle ............................................ 100% Built-in Driver ON Resistance ............................... Typ. Pch. 0.38, Nch. 0.3 (VIN=3.6V) Supply Current (at no load) ................................... Typ. 34A Standby Current .................................................... Max. 5A UVLO Detector Threshold ..................................... Typ. 2.0V Soft-start Time ....................................................... Typ. 150s LX Current Limit Circuit .......................................... Typ. 1A Package ................................................................ DFN(PLP)1616-6D (1) This is an approximate value, because output current depends on conditions and external components. 1 RP507K001B NO.EA-305-180529 APPLICATIONS Power source for portable equipment such as cellular, PDA, DSC, Notebook PC, smartphone Power source for Li-ion battery-used equipment SELECTION GUIDE Product Name Package Quantity per Reel Pb Free Halogen Free RP507K001B-TR DFN(PLP)1616-6D 5,000pcs Yes Yes Output voltage (V ) is adjustable with external divider resistors. SET Recommended output voltage range is from 0.7V to 5.5V. (1) RP507K001B has an auto-discharge function . BLOCK DIAGRAMS RP507K001B VIN Ramp Current Compensation Feedback Thermal UVLO Current Shutdown Detector LX Switching Soft Start Vref Control Mode PGND OSC Control Chip CE Enable VFB AGND (1) Auto-discharge function quickly lowers the output voltage to 0V, when the chip enable signal is switched from the active mode to the standby mode, by releasing the electrical charge accumulated in the external capacitor. 2