LM3670 Datasheet | Texas Instruments

Features - 1 Input Voltage Range: 2.5 V to 5.5 V - Adjustable Output Voltages (VOUT): 0.7 V to 2.5 V - Fixed Output Voltages: 1.2 V, 1.5 V, 1.6 V, 1.8 V, 1.875 V, 3.3V - 15-µA Typical Quiescent Current - 350-m A Maximum Load Capability - 1-MHz PWM Fixed Switching Frequency (Typical) - Automatic PFM and PWM Mode Switching - Low Dropout Operation - 100% Duty Cycle Mode - Internal Synchronous Rectification for High Efficiency - Internal Soft Start - 0.1-µA Typical Shutdown Current - Current Overload Protection - Operates from a Single Li-Ion Cell or Three-Cell Ni MH/Ni Cd Batteries - Only Three Tiny Surface-Mount External ponents Required (One Inductor, Two Ceramic Capacitors) 2 Applications - Mobile Phones and Handheld Devices - PDAs - Palm-Top PCs - Portable Instruments - Battery-Powered Devices Typical Application: Fixed Output VIN 2.5 V to 5.5 V CIN 4.7 µF VIN 1 L1 10 µF 5 SW GND 2 VOUT COUT 10 µF EN 3 4 FB 3 Description The LM3670 step-down DC-DC converter is optimized for powering ultralow voltage circuits from a single Li-Ion cell or three-cell Ni MH/Ni Cd batteries. It provides up to 350-m A load current, over an input voltage range from 2.5 V to 5.5 V. There are several different fixed voltage output options available as well as an adjustable output voltage version. The device offers superior features and performance for mobile phones and similar portable applications with plex power management systems. Automatic intelligent switching between pulse width modulation (PWM) low-noise and pulse frequency modulation (PFM) low-current mode offers improved system control. During full-power operation, a fixed-frequency 1-MHz (typical) PWM mode drives loads from approximately 70 m A to 350 m A maximum, with up to 95% efficiency. Hysteretic PFM mode extends the battery life through reduction of the quiescent current to 15 µA (typical) during light current loads and system standby. Internal synchronous rectification provides high efficiency (90% to 95% typical at...