Fairchild Fan5362 User's Manual

5362 — 3M z, 500m / 750m yn ch ro s B ck R eg lato

September 2011

FAN5362 3MHz, 500m A / 750m A Synchronous Buck Regulator Features Description

 3MHz Fixed-Frequency Operation The FAN5362 is a 500m A or 750m A, step-down, switching voltage regulator that delivers a fixed output voltage from

 45µA Typical Quiescent Current

an input voltage supply of 2.7V to 5.5V. Using a proprietary  1.80 to 3.6V Fixed Output Voltage architecture with synchronous rectification, the FAN5362 is capable of delivering a peak efficiency of 96%, while

 500m A or 750m A Output Current Capability

maintaining efficiency over 90% with load currents as

 2.7V to 5.5V Input Voltage Range low as 1m A.  Smooth Transitions to/from 100% Duty Cycle

This regulator transitions seamlessly into and out of 100%

when VIN Drops

duty cycle operation when the supply dips to or below the  PFM Mode for High Efficiency in Light Load regulation setpoint and smoothly recovers full regulation without overshoot when the supply recovers.

 Best-in-Class Load Transient Response

The regulator operates at a nominal fixed frequency of

 Best-in-Class Efficiency

3MHz, which reduces the value of the external components

 Forced PWM and External Clock Synchronization to 1µH for the output inductor and 4.7µF for the output

 Internal Soft-Start capacitor. The PWM modulator can be synchronized to an external frequency source.

 Input Under-Voltage Lockout (UVLO)

At moderate and light loads, pulse frequency modulation is

 Thermal Shutdown and Overload Protection

used to operate the device in power-save mode with a

 6-Bump WLCSP, 0.4mm Pitch or 6-Lead 2 x 2mm typical quiescent current of 45µA. Even with such a low Ultrathin Molded Leadless Package quiescent current, the part exhibits excellent transient

response during large load swings. At higher loads, the system automatically switches to fixed-frequency control,

Applications

operating at 3MHz. In shutdown mode, the supply current drops below 1µA, reducing power consumption. For

 SD Flash Memory Power Supply

applications that require minimum ripple or fixed frequency,

 RF Transceiver Power PFM mode can be disabled using the MODE pin.  Cell Phones, Smart Phones

The FAN5362 is available in 6-bump, 0.4mm pitch, Wafer-  Tablets, Netbooks®, Ultra-Mobile PCs Level Chip-Scale Package (WLCSP) and 6-Lead 2 x 2mm Ultrathin Molded Leadless Package (UMLP).

 3G, LTE, Wi MAX™, Wi Bro®, and Wi Fi® Data Cards  Gaming Devices, Digital Cameras DC/DC Micro Modules

MODE VIN

SW ENL1 CIN

FB GND C1 C2

Figure 1. Typical Application

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© 2009 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN5362 • Rev. 1.0.4