FAN53540: 2.4 MHz, 5 A TinyBuck Synchronous Buck Regulator

Not Recommended For New Design as of 14-Jan-2013

The FAN53540 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 FAN53540 is capable of delivering 5A 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 2.4MHz, 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.

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 FAN53540 is available in a 20-bump 1.96 mm x 1.56 mm Wafer-Level Chip-Scale Package (WLCSP).

Features

• 2.4 MHz Fixed-Frequency Operation
• Best-in-Class Load Transient Response
• 5A Output Current Capability
• 2.7 V to 5.5 V Input Voltage Range
• Adjustable Output Voltage: 0.8 V to V_IN
• 0.9
• 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