Datasheet
1
2
5
43
V
IN
SW
FB
EN
GND
L1:10uH
V
OUT
C
OUT
10uF
C
IN
4.7uF
LM3670
V
IN
2.5V to 5.5V
LM3670
www.ti.com
SNVS250E –NOVEMBER 2004–REVISED FEBRUARY 2013
LM3670 Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits
Check for Samples: LM3670
1
FEATURES
APPLICATIONS
2
• V
OUT
= Adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875,
• Mobile Phones
2.5, 3.3V
• HandHeld
• 2.5V ≤ V
IN
≤ 5.5V
• PDAs
• 15 µA Typical Quiescent Current
• Palm-Top PCs
• 350 mA Maximum Load Capability
• Portable Instruments
• 1 MHz PWM Fixed Switching Frequency (typ.)
• Battery Powered Devices
• Automatic PFM/PWM Mode Switching
DESCRIPTION
• Available in Fixed Output Voltages as well as
The LM3670 step-down DC-DC converter is
an Adjustable Version
optimized for powering ultra-low voltage circuits from
• SOT-23-5 Package
a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It
• Low Drop Out Operation - 100% Duty Cycle
provides up to 350 mA load current, over an input
Mode
voltage range from 2.5V to 5.5V. There are several
different fixed voltage output options available as well
• Internal Synchronous Rectification for High
as an adjustable output voltage version.
Efficiency
• Internal Soft Start
The device offers superior features and performance
for mobile phones and similar portable applications
• 0.1 µA Typical Shutdown Current
with complex power management systems. Automatic
• Operates from a Single Li-Ion Cell or 3 Dell
intelligent switching between PWM low-noise and
NiMH/NiCd Batteries
PFM low-current mode offers improved system
• Only Three Tiny Surface-Mount External
control. During full-power operation, a fixed-frequency
1 MHz (typ). PWM mode drives loads from ∼70 mA to
Components Required (One Inductor, Two
350 mA max, with up to 95% efficiency. Hysteretic
Ceramic Capacitors)
PFM mode extends the battery life through reduction
• Current Overload Protection
of the quiescent current to 15 µA (typ) during light
current loads and system standby. Internal
synchronous rectification provides high efficiency (90
to 95% typ. at loads between 1 mA and 100 mA). In
shutdown mode (Enable pin pulled low) the device
turns off and reduces battery consumption to 0.1 µA
(typ.).
Typical Application
Figure 1. Fixed Output Voltage
1
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PRODUCTION DATA information is current as of publication date.
Copyright © 2004–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.