Description
The FAN53541 is a step-down switching voltage regulator that delivers an adjustable output from an input voltage supply of 2.7 V to 5.5 V. Using a proprietary architecture with synchronous rectification, the FAN53541 is capable of delivering 5 A at over 90% efficiency, while maintaining a very high efficiency of over 80% at load currents as low as 2 mA. The regulator operates at a nominal fixed frequency of 2.4 MHz, which reduces the value of the external components to 470 nH for the output inductor and 20 µF for the output capacitor. Additional output capacitance can be added to improve regulation during load transients without affecting stability and inductance up to 1.2 µH may be used with additional output capacitance.

Features
■ 2.4 MHz Fixed-Frequency Operation
■ Best-in-Class Load Transient Response
■ 5 A Output Current Capability
■ 2.7 V to 5.5 V Input Voltage Range
■ Adjustable Output Voltage: 0.8 V to 90% of VIN
■ PFM Mode for High Efficiency in Light Load (Forced PWM Available on MODE Pin)
■ 50 µA Typical Quiescent Current in PFM Mode
■ External Frequency Synchronization
■ Low Ripple Light-Load PFM Mode with Forced PWM Control
■ Power Good Output
■ Internal Soft-Start
■ Input Under-Voltage Lockout (UVLO)
■ Thermal Shutdown and Overload Protection
■ No External Compensation Required
■ 20-Bump WLCSP

Applications
■ Set-Top Box
■ Hard Disk Drive
■ Communications Cards
■ DSP Power