LM3676_14 Datasheet, PDF (1/23 Pages) Texas Instruments – 2MHz, 600mA Step-Down DC-DC Converter with Mode Control

LM3676
www.ti.com
SNVS426B – NOVEMBER 2006 – REVISED MARCH 2007
LM3676 2MHz, 600mA Step-Down DC-DC Converter with Mode Control
Check for Samples: LM3676
FEATURES
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•2 16 µA typical quiescent current
• 600 mA maximum load capability
• 2 MHz PWM fixed switching frequency (typ)
• Automatic PFM/PWM mode switching or
Forced PWM mode
• Available in fixed output voltages and
adjustable version
• 8-Lead non-pullback LLP package
• Internal synchronous rectification for high
efficiency
• Internal soft start
• 0.01 µA typical shutdown current
• Operates from a single Li-Ion cell battery
• Only three tiny surface-mount external
components required (one inductor, two
ceramic capacitors)
• Current overload and Thermal shutdown
protection
APPLICATIONS
• Mobile phones
• PDAs
• MP3 players
• W-LAN
• Portable instruments
• Digital still cameras
• Portable Hard disk drives
DESCRIPTION
The LM3676 step-down DC-DC converter is optimized for powering low voltage circuits from a single Li-Ion cell
battery and input voltage rails from 2.9V to 5.5V. It provides up to 600mA load current, over the entire input
voltage range. There are several different fixed voltage output options available as well as an adjustable output
voltage version.
The LM3676 has a mode-control pin that allows the user to select continuous Forced PWM mode over the
complete load range or an intelligent PFM-PWM mode that changes modes depending on the load. PWM mode
offers superior efficiency under high load conditions (>100mA) and the lowest output noise performance. In Auto
mode, PFM-PWM, hysteretic PFM extends the battery life through reduction of the quiescent current to 16µA
(typ.) during light loads and system standby.
The LM3676 is available in a 8-lead non-pullback LLP package in leaded (PB) and lead-free (NO PB) versions. A
high switching frequency of 2 MHz (typ) allows use of tiny surface-mount components, an inductor and two
ceramic capacitors.
Typical Application Circuits
V_IN
2.9V to 5.5V
C_IN
4.7 PF
V_IN
8
L1: 2.2 PH
2 ^SW
PGND
NC
EN
LM3676
1
4
6
7
FB
SGND
5
3 ^MODE
V_OUT
C_OUT
10 PF
Figure 1. Typical Application Circuit
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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 © 2006–2007, Texas Instruments Incorporated