LM3673_15 Datasheet, PDF (1/28 Pages) Texas Instruments – 2-MHz, 350-mA Step-Down DC-DC Converter

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LM3673
SNVS434L – JULY 2006 – REVISED OCTOBER 2015
LM3673 2-MHz, 350-mA Step-Down DC-DC Converter
1 Features
•1 16-µA Typical Quiescent Current
• 350-mA Maximum Load Capability
• 2-MHz PWM Fixed Switching Frequency (Typical)
• Automatic PFM/PWM Mode Switching
• Available in Fixed and Adjustable Output Voltages
• 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
• Only Three Tiny Surface-Mount External
Components Required (One Inductor, Two
Ceramic Capacitors)
2 Applications
• Mobile Phones
• PDAs
• MP3 Players
• W-LAN
• Portable Instruments
• Digital Still Cameras
• Portable Hard Disk Drives
3 Description
The LM3673 step-down DC-DC converter is
optimized for powering low voltage circuits from a
single Li-Ion cell battery and input voltage rails from
2.7 V to 5.5 V. It provides up to 350-mA 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 ranging
from 1.1 V to 3.3 V.
The device offers superior features and performance
for mobile phones and similar portable systems. The
LM3673 uses intelligent automatic switching between
pulse width modulation (PWM) and pulse frequency
modulation (PFM) for better efficiency. During PWM
mode, the device operates at a fixed-frequency of
2 MHz (typical). Hysteretic PFM mode extends the
battery life by reducing the quiescent current to 16 µA
(typical) during light load and standby operation.
Internal synchronous rectification provides high
efficiency during PWM mode operation. In shutdown
mode, the device turns off and reduces battery
consumption to 0.01 µA (typical).
The LM3673 is available in a tiny 5-pin DSBGA
package. A high switching frequency of 2 MHz
(typical) allows the use of three tiny surface-mount
components: an inductor and two ceramic capacitors.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (MAX)
LM3673
DSBGA (5)
1.413 mm × 1.083 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
VIN
2.7 V to 5.5 V
CIN
4.7 µF
Typical Application Circuit
VIN
1
L1: 2.2 µH
5 ^SW
LM3673
GND
2
EN ₃
4 ^FB
VOUT
COUT
10 µF
Typical Application Circuit for ADJ Version
V_IN
2.7 V to 5.5 V
C_IN
4.7 µF
VIN
1
L1: 2.2 µH
5 ^SW
LM3673-
GND ^ADJ
2
C1
R1
V_OUT
C_OUT
10 µF
EN ₃
4 ^{FB C2}
R2
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.