LM3679_15 Datasheet, PDF (1/24 Pages) Texas Instruments – 3MHz, 350mA Miniature Step-Down DC-DC Converter for Ultra Low Profile Applications (Height < 0.55mm)

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
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•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
V_IN
2.5V to 5.5V
C_IN
4.7 PF
V_{IN 1}
L1: 1.0 PH
5 ^SW
LM3679
GND ₂
EN ₃
4 ^FB
V_OUT
C_OUT
10 PF
Bill of Materials for Low Profile Solution:
CIN = JMK107BJ475K (Taiyo - Yuden)
COUT = JMK107BJ475K (Taiyo - Yuden) x2
Inductor = LQM21PN1R0MC0 (MuRata)
Figure 1. Typical Low Profile Application Circuit
(0.55mm max height using LM3679UR)
Figure 2. Efficiency vs. Output Current (V_OUT =
1.8V)
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007–2008, Texas Instruments Incorporated