FAN5631

FAN5631 / FAN5632 — Regulated Step Down Charge Pump DC/DC Converter October 2007 FAN5631 / FAN5632 Regulated Step-Down Charge Pump DC/DC Converter Features ƒ 90% Peak Efficiency ƒ Low EMI ƒ Low Ripple ƒ Selectable Output Voltage:1.2V/1.5V for FAN5631 ƒ Efficiency Optimizer Feature for FAN5632 ƒ Input Voltage Range: 2.2V to 5.5V ƒ Output Current: Up to 250mA ƒ ±5% Output Voltage Accuracy ƒ 30µA Operating Current ƒ ICC<1mA in Shutdown Mode ƒ 1.5MHz Operating Frequency ƒ Shutdown Isolates Output from Input ƒ Soft-Start Limits Inrush Current ƒ Short-Circuit and Over-Temperature Protection ƒ Minimum External Component Count ƒ 10-Lead 3x3mm MLP Package Applications ƒ Cell Phones ƒ Handheld Computers ƒ Portable Electronic Equipment ƒ Core Supply to Next-Generation Processors ƒ Low-Voltage DC Bus ƒ Digital Cameras ƒ DSP Supplies Description The FAN5631/FAN5632 is an advanced, thirdgeneration switched capacitor step-down DC/DC converter utilizing Fairchild's proprietary ScalarPump technology. This innovative architecture utilizes scalar switch re-configuration and fractional switching techniques to produce low output ripple, lower ESR spikes, and improve efficiency over a wide load range. The FAN5631/FAN5632 produces a fixed regulated output voltage from an input voltage of 2.2V to 5V. To maximize efficiency, the FAN5631/5632 achieves regulation by skipping pulses. Depending on load current, the size of the switches are scaled dynamically; consequently, current spikes and EMI are ...