LM3679

LM3679 www.ti.com SNVS510A – SEPTEMBER 2007 – REVISED FEBRUARY 2008 LM3679 3MHz, 350mA Miniature Step-Down DC-DC Converter for Ultra Low Profile Applications (Height < 0.55mm) Check for Samples: LM3679 FEATURES 1 2 16 µA Typical Quiescent Current 350 mA Maximum Load Capability 3 MHz PWM Fixed Switching Frequency (typ) Automatic PFM/PWM Mode Switching Available in 5-Bump DSBGA YZR Package and YPD Package Internal Synchronous Rectification for High Efficiency Internal Soft Start 0.01 µA Typical Shutdown Current Operates from a Single Li-Ion Cell Battery Current Overload and Thermal Shutdown Protection Three External Components Required for Typical Applications Low Profile Solution (0.55mm Max Height, Includes Four External Components) APPLICATIONS Mobile Phones PDAs MP3 Players W-LAN Portable Instruments Digital Still Cameras Portable Hard Disk Drives DESCRIPTION The LM3679 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell battery and input voltage rails from 2.5V to 5.5V. It provides up to 350mA load current, over the entire input voltage range. The LM3679 output voltage can be configured to 1.2V, 1.5V, or 1.8V. TYPICAL APPLICATION CIRCUIT VIN 2.5V to 5.5V CIN 4.7 PF VIN 1 L1: 1.0 PH 5 SW LM3679 GND 2 EN 3 4 FB VOUT COUT 10 PF Bill of Materials for Low Profile Solution: CIN = JMK107BJ475K (Taiyo - Yuden) COUT = JMK107BJ475K (Taiyo - Yuden) x2 Inductor = LQM21PN1R0MC0 (MuRa...