FAN5361: 6MHz, 600mA / 750mA Synchronous Buck Regulator

The FAN5361 is a 600mA or 750mA, step-down, switching voltage regulator that delivers a fixed output from an input voltage supply of 2.3V to 5.5V. Using a proprietary architecture with synchronous rectification, the FAN5361 is capable of delivering a peak efficiency of 92%, while maintaining efficiency over 80% at load currents as low as 1mA.

The regulator operates at a nominal fixed frequency of 6MHz, which reduces the value of the external components to 470nH for the output inductor and 4.7µF for the output capacitor. The PWM modulator can be synchronized to an external frequency source.

At moderate and light loads, pulse frequency modulation is used to operate the device in Power-Save Mode with a typical quiescent current of 35µA. 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 6MHz. In Shutdown Mode, the supply current drops below 1µA, reducing power consumption. For applications that require minimum ripple or fixed frequency, PFM Mode can be disabled using the MODE pin.

The FAN5361 is available in 6-bump, 0.4mm pitch, Wafer-Level Chip-Scale Package (WLCSP) and a 6-lead 2 x 2mm ultra-thin MLP package (UMLP).

Features

• 6MHz Fixed-Frequency Operation
• 35µA Typical Quiescent Current
• Best-in-Class Load Transient Response
• Best-in-Class Efficiency
• 600mA or 750mA Output Current Capability
• 2.3V to 5.5V Input Voltage Range
• 1.0 to 1.82V Fixed Output Voltage
• Low Ripple Light-Load PFM Mode
• Forced PWM and External Clock Synchronization
• Internal Soft-Start
• Input Under-Voltage Lockout (UVLO)
• Thermal Shutdown and Overload Protection
• 6-bump WLCSP, 0.4mm Pitch
• 6-pin 2 x 2mm UMLP