•2 MHz PWM Fixed Switching Frequency (typ.)•MP3 Players
•Automatic PFM/PWM Mode Switching•W-LAN
•Internal Synchronous Rectification for High•Portable Instruments
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
•Available in Fixed Output Voltages and
Adjustable Version
•LM3671Q is an Automotive Grade Product that
is AEC-Q100 Grade 1 Qualified
•SOT-23, 5-Bump DSBGA and 6-Pin USON
Packages
APPLICATIONS
•Mobile Phones
•Digital Still Cameras
•Portable Hard Disk Drives
•Automotive
DESCRIPTION
TheLM3671step-downDC-DCconverteris
optimized for powering low voltage circuits from a
single Li-Ion cell battery and input voltage rails from
2.7V to 5.5V. It provides up to 600 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 range from
1.1V to 3.3V.
The device offers superior features and performance
for mobile phones and similar portable systems.
Automatic intelligent switching between PWM lownoise and PFM low-current mode offers improved
system control. During PWM mode, the device
operates at a fixed-frequency of 2 MHz (typ.).
Hysteretic PFM mode extends the battery life by
reducing the quiescent current to 16 µA (typ.) during
lightloadandstandbyoperation.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 (typ.).
LM3671
LM3671Q
TYPICAL APPLICATION CIRCUITS
Figure 1. Typical Application Circuit
1
2All trademarks are the property of their respective owners.
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.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
The LM3671 is available in SOT-23, tiny 5-bump DSBGA and a 6-pin USON packages in leaded (PB) and leadfree (NO PB) versions. A high-switching frequency of 2 MHz (typ.) allows use of tiny surface-mount components.
Only three external surface-mount components, an inductor and two ceramic capacitors, are required.
Figure 2. Typical Application Circuit for ADJ version
Connection Diagrams
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Figure 3. Top View
SOT-23 Package
See Package Number DBV (2.92 mm x 2.84 mm x 1.2 mm)
Figure 4. 5-Bump DSBGA Package
See Package Number YZR0005 (1.05 mm x 1.38 mm x 0.6 mm)
See Package Number NKH0006B (2 mm x 2 mm x 0.6 mm)
PIN DESCRIPTIONS (SOT-23)
1V
IN
2GNDGround pin.
3ENEnable pin. The device is in shutdown mode when voltage to this pin is <0.4V and enabled
4FBFeedback analog input. Connect directly to the output filter capacitor for fixed voltage
5SWSwitching node connection to the internal PFET switch and NFET synchronous rectifier.
Power supply input. Connect to the input filter capacitor (Figure 1).
when >1.0V. Do not leave this pin floating.
versions. For adjustable version external resistor dividers are required (Figure 2). The
internal resistor dividers are disabled for the adjustable version.
PIN DESCRIPTIONS (5-Bump DSBGA)
Pin #NameDescription
A1V
IN
Power supply input. Connect to the input filter capacitor (Figure 1).
A3GNDGround pin.
C1ENEnable pin. The device is in shutdown mode when voltage to this pin is <0.4V and enabled
when >1.0V. Do not leave this pin floating.
C3FBFeedback analog input. Connect directly to the output filter capacitor for fixed voltage
versions. For adjustable version external resistor dividers are required (Figure 2). The
internal resistor dividers are disabled for the adjustable version.
B2SWSwitching node connection to the internal PFET switch and NFET synchronous rectifier.
PIN DESCRIPTIONS (6-Pin USON)
Pin #NameDescription
1ENEnable pin. The device is in shutdown mode when voltage to this pin is <0.4V and enabled
2PgndGround pin.
3V
IN
4SWSwitching node connection to the internal PFET switch and NFET synchronous rectifier.
5SgndSingnal ground (feedback ground).
6FBFeedback analog input. Connect directly to the output filter capacitor for fixed voltage
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
when >1.0V. Do not leave this pin floating.
Power supply input. Connect to the input filter capacitor (Figure 1).
versions. For adjustable version external resistor dividers are required (Figure 2). The
internal resistor dividers are disabled for the adjustable version.
VINPin: Voltage to GND−0.2V to 6.0V
FB, SW, EN Pin:(GND−0.2V) to
Continuous Power Dissipation
Junction Temperature (T
(3)
)+125°C
J-MAX
Storage Temperature Range−65°C to +150°C
Maximum Lead Temperature260°C
(Soldering, 10 sec.)
ESD Rating
(4)
Human Body Model2 kV
Machine Model200V
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings are conditions under
which operation of the device is specified. Operating Ratings do not imply specified performance limits. For specified performance limits
and associated test conditions, see the Electrical Characteristics tables.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office / Distributors for
availability and specifications.
(3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ= 150°C (typ.) and
disengages at TJ= 130°C (typ.).
(4) The Human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200 pF
capacitor discharged directly into each pin. MIL-STD-883 3015.7
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(VIN+ 0.2V)
Internally Limited
OPERATING RATINGS
Input Voltage Range
(3)
(1) (2)
2.7V to 5.5V
Recommended Load Current0mA to 600 mA
Junction Temperature (TJ) Range−40°C to +125°C
Ambient Temperature (TA) Range
(4)
−40°C to +85°C
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings are conditions under
which operation of the device is specified. Operating Ratings do not imply specified performance limits. For specified performance limits
and associated test conditions, see the Electrical Characteristics tables.
(2) All voltages are with respect to the potential at the GND pin.
(3) The input voltage range recommended for ideal applications performance for the specified output voltages are given below:VIN= 2.7V to
4.5V for 1.1V ≤ V
V
DROPOUT
(4) In Applications where high power dissipation and/or poor package resistance is present, the maximum ambient temperature may have
= I
to be derated. Maximum ambient temperature (T
maximum power dissipation of the device in the application (P
in the application, as given by the following equation:T
different ambient temperatures.
< 1.5VVIN= 2.7V to 5.5V for 1.5V ≤ V
OUT
LOAD
*( R
DSON, PFET
+ R
INDUCTOR
< 1.8VVIN= (V
)
A-MAX
OUT
) is dependent on the maximum operating junction temperature (T
) and the junction to ambient thermal resistance of the package (θJA)
D-MAX
= T
A-MAX
J-MAX
− (θJAx P
+ V
OUT
). Refer to Dissipation rating table for P
D-MAX
DROPOUT
) to 5.5V for 1.8V ≤ V
≤ 3.3Vwhere
OUT
J-MAX
D-MAX
), the
values at
THERMAL PROPERTIES
Junction-to-Ambient Thermal Resistance (θJA) (SOT-23) for 4-layer board
Junction-to-Ambient Thermal Resistance (θJA) (DSBGA) for 4-layer board
Junction-to-Ambient Thermal Resistance (θJA) (USON) for 4-layer board
(1) Junction to ambient thermal resistance is highly application and board layout dependent. In applications where high power dissipation
exists, special care must be given to thermal dissipation issues in board design. Specified value of 130 °C/W for SOT-23 is based on a 4
layer, 4" x 3", 2/1/1/2 oz. Cu board as per JEDEC standards is used.
Limits in standard typeface are for TJ= 25°C. Limits in boldface type apply over the entire junction temperature range for
operation, −40°C to +125°C. Unless otherwise noted, specifications apply to the LM3671MF/TL/LC with VIN= EN = 3.6V
SymbolParameterConditionMinTypMaxUnits
V
IN
Input Voltage
Feedback Voltage (Fixed) MF−4+4
Feedback Voltage (Fixed) TLPWM mode
Feedback Voltage (Fixed) LC−4+4
Feedback Voltage (ADJ) MF
V
FB
(6)
Feedback Voltage (ADJ) TL−2.5+2.5
Line Regulation0.031%/V
Pin-Pin Resistance for PFETVIN= VGS= 3.6V380500mΩ
Pin-Pin Resistance for NFETVIN= VGS= 3.6V250400mΩ
Switch Peak Current LimitOpen Loop
Logic High Input1.0V
Logic Low Input0.4V
Enable (EN) Input Current0.011µA
Internal Oscillator FrequencyPWM Mode
(1) All voltages are with respect to the potential at the GND pin.
(2) Min and Max limits are specified by design, test or statistical analysis. Typical numbers are not specified, but do represent the most
likely norm.
(3) The parameters in the electrical characteristic table are tested at VIN= 3.6V unless otherwise specified. For performance over the input
voltage range refer to datasheet curves.
(4) The input voltage range recommended for ideal applications performance for the specified output voltages are given below:VIN= 2.7V to
4.5V for 1.1V ≤ V
V
DROPOUT
(5) Test condition: for V
= I
(6) ADJ version is configured to 1.5V output. For ADJ output version: VIN= 2.7V to 4.5V for 0.90V ≤ V
≤ V
< 3.3V
OUT
(7) Refer to datasheet curves for closed loop data and its variation with regards to supply voltage and temperature. Electrical Characteristic
< 1.5VVIN= 2.7V to 5.5V for 1.5V ≤ V
OUT
LOAD
*( R
DSON, PFET
less than 2.5V, VIN= 3.6V; for V
OUT
+ R
INDUCTOR
)
table reflects open loop data (FB=0V and current drawn from SW pin ramped up until cycle by cycle current limit is activated). Closed
loop current limit is the peak inductor current measured in the application circuit by increasing output current until output voltage drops
by 10%.
(4)
(5)
PWM mode
(5)
2.7V ≤ VIN≤ 5.5V
IO= 10 mA
100 mA ≤ IO≤ 600 mA
VIN= 3.6V
No load, device is not switching (FB
forced higher than programmed1635µA
output voltage)