FAN53541 Datasheet | Fairchild Semiconductor

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 pensation Required - 20-Bump WLCSP Applications - Set-Top Box - Hard Disk Drive - munications Cards - DSP Power 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 m A. The regulator operates at a nominal fixed frequency of 2.4 MHz, which reduces the value of the external ponents to 470 n H 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. At moderate and light loads, pulse frequency modulation (PFM) is used to operate the device in power-save mode with a typical quiescent current of 50 µA. Even with such a low quiescent current, the part exhibits excellent transient response during large load swings. At higher loads, the system automatically switches to fixed-frequency control, operating at 2.4 MHz. In shutdown mode, the supply current drops below 1 µA, reducing power consumption. PFM mode can be disabled if constant frequency is desired. The FAN53541 is available in a 20-bump 1.96 mm x 1.56 mm Wafer-Level...