LM3670   
Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits from the PowerWise® Family		 Click link to Download

Features
•VOUT = Adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
•2.5V <= VIN <= 5.5V
•15 µA typical quiescent current
•350 mA maximum load capability
•1 MHz PWM fixed switching frequency (typ.)
•Automatic PFM/PWM mode switching
•Available in fixed output voltages as well as an adjustable version
•SOT23-5 package
•Low drop out operation - 100% duty cycle mode
•Internal synchronous rectification for high efficiency
•Internal soft start
•0.1 µA typical shutdown current
•Operates from a single Li-Ion cell or 3 cell NiMH/NiCd batteries
•Only three tiny surface-mount external components required (one inductor, two ceramic capacitors)
•Current overload protection

Description

The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 350 mA load current, over an input voltage range from 2.5V to 5.5V. There are several different fixed voltage output options available as well as an adjustable output voltage version (see ordering information).

The device offers superior features and performance for mobile phones and similar portable applications with complex power management systems. Automatic intelligent switching between PWM low-noise and PFM low-current mode offers improved system control. During full-power operation, a fixed-frequency 1 MHz (typ). PWM mode drives loads from [Similar_To]70 mA to 350 mA max, with up to 95% efficiency. Hysteretic PFM mode extends the battery life through reduction 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.).

The LM3670 is available in a SOT23-5 package. A high switching frequency - 1 MHz (typ) - allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required.

Applications
•Mobile phones
•HandHeld
•PDAs
•Palm-top PCs
•Portable Instruments
•Battery Powered Devices
WEBENCH Power Designer My Designs

LM3670
 
2.50 <=		 V in Lower
 V		  
<=		 V in Upper
 V		  
<= 5.50
V out 1.00 <=  V <= 3.30
I out    A <= 0.35
Ambient Temperature  °C <= 100


What are WEBENCH® tools?

Also Recommended
LM3671▲2 MHz Switching Frequency, 600mA Output Current
LM3674▲2 MHz Switching Frequency, 600mA Output Current With PWM Only Mode



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                                              LM3670
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Also Recommended
LM3671▲2 MHz Switching Frequency, 600mA Output Current
LM3674▲2 MHz Switching Frequency, 600mA Output Current With PWM Only Mode

Typical Application
click for larger image


Connection Diagram
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Typical Performance
click for larger image


Paramaters / ValuesLM3670 LM3671 LM3674
Output Current350 mA 600 mA 600 mA
Input Min Voltage2.5 Volt 2.7 Volt 2.7 Volt
Input Max Voltage5.5 Volt 5.5 Volt 5.5 Volt
Output Min1.8, 0.7, 1.875, 1.2, 3.3, 1.6, 1.5 Volt 1.8, 2.5, 1.1, 1.875, 1.2, 3.3, 1.375, 1.25, 2.8, 1.6, 1.5 Volt 1.8, 1.1, 1.875, 1.2, 2.8, 1.5 Volt
Output Max1.8, 2.5, 1.875, 1.2, 3.3, 1.6, 1.5 Volt 1.8, 2.5, 1.875, 1.2, 3.3, 1.375, 1.25, 2.8, 1.6, 1.5 Volt 1.8, 1.875, 1.2, 3.3, 2.8, 1.5 Volt
Frequency Min1000 kHz 2000 kHz 2000 kHz
Frequency Max1000 kHz 2000 kHz 2000 kHz
Efficiency (peak)95 % 96 % 96 %
On/Off PinYes Yes Yes
Error FlagNo No No
SoftStartYes Yes Yes
Sync PinNo No No
InvertingNo No No
FlybackNo No No
RegTypeSwitching Regulator Switching Regulator Switching Regulator
Temperature Min-40 deg C -30 deg C -30 deg C
Temperature Max85 deg C 85 deg C 85 deg C
Adjustable OutputNo, Yes No, Yes No, Yes
Adj Switch FrequencyNo No No
PWM ModeVoltage with input feedfoward Voltage with input feedforward Voltage with input feedforward
TopologySynchronous Buck Synchronous Buck Synchronous Buck
Special FeaturesPin-selectable PWM/PFM modes, Iq=15uA, 100% duty cycle, internal compensation, ceramic-cap stable, only 3 external components Pin-selectable PWM/PFM modes, Iq=15uA, 100% duty cycle, internal compensation, ceramic-cap stable, only 3 external components Pin-selectable PWM/PFM modes, Iq=15uA, 100% duty cycle, internal compensation, ceramic-cap stable, only 3 external components
Step-DownYes Yes Yes
Multiple Output CapabilityNo No No
Output PowerUndefined Watt Undefined Watt Undefined Watt
Output Voltage1.8, Undefined, 1.875, 3.3, 1.6, 1.5 Volt 1.8, Undefined, 2.5, 1.875, 1.2, 3.3, 1.375, 1.25, 2.8, 1.6, 1.5 Volt 1.8, Undefined, 1.875, 1.2, 2.8, 1.5 Volt
Output Range0.7V to 3.3V 1.1V to 3.3V Undefined
Switching Frequency1000 kHz 2000 kHz 2000 kHz
Feedback VoltageUndefined Volt Undefined Volt Undefined Volt
Regulator FamilyUndefined Undefined Undefined
PowerWiseYes Yes Yes
Synchronous RectificationYes Yes Yes

Datasheet
TitleSizeDateOther
Language
LM3670 Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits982
Kbytes		23-Jan-06 


Featured Application Notes
TitleSizeDateOther
Language
AN-1348: Application Note 1348 LM3670 Evaluation Board3906
Kbytes		9-Oct-08 中文


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Part Number(s)
(NSID)		Top ViewAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM3670MF-2.5/NOPB
LM3670MF-2.5

RoHS



SOT-23		Lifetime buy
Lead Time: 6 weeks

 
DistributorRegionQty
AVNET-EMWorldwide875
DIGIKEYWorldwide0
KEIKONGAsia Pacific1000
$1.03 each at 1K+ pcsreel
of
1000
LM3670MF-1.2/NOPB

RoHS



SOT-23		Full production
Lead Time: 6 weeks

Samples
DistributorRegionQty
ARROWWorldwide2000
DIGIKEYWorldwide1881
KEIKONGAsia Pacific27000
NEWARKAmericas648
$0.70 each at 1K+ pcsreel
of
1000
LM3670MF-1.5/NOPB

RoHS



SOT-23		Full production
Lead Time: 6 weeks

Samples
DistributorRegionQty
DIGIKEYWorldwide1476
KEIKONGAsia Pacific1000
$0.70 each at 1K+ pcsreel
of
1000
LM3670MF-1.6/NOPB

RoHS



SOT-23		Full production
Lead Time: 12 weeks

Samples
DistributorRegionQty
DIGIKEYWorldwide1983
$0.70 each at 1K+ pcsreel
of
1000
LM3670MF-1.8/NOPB
LM3670MF-1.8

RoHS



SOT-23		Full production
Lead Time: 6 weeks

Samples
DistributorRegionQty
DIGIKEYWorldwide1372
FARNELLEurope and Asia388
FUTUREWorldwide1100
KEIKONGAsia Pacific5000
NEWARKAmericas975
RS COMPONENTSWorldwide3
$0.70 each at 1K+ pcsreel
of
1000
LM3670MF-1.875/NOPB

RoHS



SOT-23		Full production
Lead Time: 12 weeks

Samples
DistributorRegionQty
DIGIKEYWorldwide1850
$0.70 each at 1K+ pcsreel
of
1000
LM3670MF-3.3/NOPB
LM3670MF-3.3

RoHS



SOT-23		Full production
Lead Time: 12 weeks

Samples
DistributorRegionQty
ARROWWorldwide1000
AVNET-EMWorldwide1000
DIGIKEYWorldwide1736
NEWARKAmericas1000
$0.70 each at 1K+ pcsreel
of
1000
LM3670MF-ADJ/NOPB

RoHS



SOT-23		Full production
Lead Time: 6 weeks

Samples
DistributorRegionQty
AVNET-EMWorldwide1000
DIGIKEYWorldwide2253
FARNELLEurope and Asia3063
FUTUREWorldwide502
KEIKONGAsia Pacific3000
NEWARKAmericas681
RS COMPONENTSWorldwide806
$0.70 each at 1K+ pcsreel
of
1000
LM3670MFX-3.3/NOPB

RoHS



SOT-23		Lifetime buy
Lead Time: 12 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$1.03 each at 1K+ pcsreel
of
3000
LM3670MFX-1.2/NOPB

RoHS



SOT-23		Full production
Lead Time: 6 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$0.70 each at 1K+ pcsreel
of
3000
LM3670MFX-1.5/NOPB

RoHS



SOT-23		Full production
Lead Time: 12 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$0.70 each at 1K+ pcsreel
of
3000
LM3670MFX-1.6/NOPB

RoHS



SOT-23		Full production
Lead Time: 12 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$0.70 each at 1K+ pcsreel
of
3000
LM3670MFX-1.8/NOPB

RoHS



SOT-23		Full production
Lead Time: 6 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$0.70 each at 1K+ pcsreel
of
3000
LM3670MFX-1.875/NOPB

RoHS



SOT-23		Full production
Lead Time: 12 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$0.70 each at 1K+ pcsreel
of
3000
LM3670MFX-ADJ/NOPB

RoHS



SOT-23		Full production
Lead Time: 6 weeks

 
DistributorRegionQty
AVNET-EMWorldwide3000
DIGIKEYWorldwide3569
KEIKONGAsia Pacific12000
$0.70 each at 1K+ pcsreel
of
3000

Obsolete Versions
Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
LM3670MF-2.5
NONE
NATIONAL SEMICONDUCTOR
01 Dec 2009
LM3670MFX-3.3
NONE
NATIONAL SEMICONDUCTOR
01 Dec 2009

Part Number(s)
(NSID)		DescriptionAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM3670MF-1.2EV
Miniature Step-Down DC-DC Converter for Ultra Low Voltage CircuitsFull production


 
DistributorRegionQty
DIGIKEYWorldwide0
NATIONALWorldwide41
$75.00 each1

The LM3670 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 350 mA load current, over an input voltage range from 2.5V to 5.5V. There are several different fixed voltage output options available as well as an adjustable output voltage version. This device offers superior features and performance for mobile phones and similar portable applications with complex power management systems.

LM3670 Features:

  • Vout = adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
  • 2.5V less than or equal to Vin less than or equal to 5.5V
  • 1.5 microA typical quiescent current
  • 350 mA maximum load capability
  • 1 MHz PWM fixed switching frequency (typ.)
  • Automatic PFM/PWM mode switching
  • Available in fixed output voltages as well as an adjustable version
  • SOT23-5 package
  • Low drop out operation - 100% duty cycle mode
  • Internal synchronous rectification for high efficiency
  • Internal soft start
  • 0.1 microA typical shutdown current
  • Operates from a single Li-Ion cell or 3 cell NIMH/NiCd batteries
  • Only three tiny surface-mount external components required (one inductor, two ceramic capaitors)
  • Current overload protection

Applications:

  • Mobile phones
  • Hand-Held Radios
  • Personal Digital Assistants
  • Palm-top PCs
  • Portable Instruments
  • Battery Powered Devices

Part Number(s)
(NSID)		DescriptionAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM3670MF-1.5EV
Miniature Step-Down DC-DC Converter for Ultra Low Voltage CircuitsFull production


 
DistributorRegionQty
DIGIKEYWorldwide0
NATIONALWorldwide7
$75.00 each1

The LM3670 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 350 mA load current, over an input voltage range from 2.5V to 5.5V. There are several different fixed voltage output options available as well as an adjustable output voltage version. This device offers superior features and performance for mobile phones and similar portable applications with complex power management systems.

Features:

  • Vout = adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
  • 2.5V less than or equal to Vin less than or equal to 5.5V
  • 1.5 microA typical quiescent current
  • 350 mA maximum load capability
  • 1 MHz PWM fixed switching frequency (typ.)
  • Automatic PFM/PWM mode switching
  • Available in fixed output voltages as well as an adjustable version
  • SOT23-5 package
  • Low drop out operation - 100% duty cycle mode
  • Internal synchronous rectification for high efficiency
  • Internal soft start
  • 0.1 microA typical shutdown current
  • Operates from a single Li-Ion cell or 3 cell NIMH/NiCd batteries
  • Only three tiny surface-mount external components required (one inductor, two ceramic capaitors)
  • Current overload protection

Applications:

  • Mobile phones
  • Hand-Held Radios
  • Personal Digital Assistants
  • Palm-top PCs
  • Portable Instruments
  • Battery Powered Devices

Part Number(s)
(NSID)		DescriptionAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM3670MF-1.8EV
Miniature Step-Down DC-DC Converter for Ultra Low Voltage CircuitsFull production


 
DistributorRegionQty
DIGIKEYWorldwide0
NATIONALWorldwide5
$75.00 each1

The LM3670 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 350 mA load current, over an input voltage range from 2.5V to 5.5V. There are several different fixed voltage output option available as well as an adjustable output voltage version. This device offers superior features and performance for mobile phones and similar portable applications with complex power management systems.

Features:

  • Vout = adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
  • 2.5V less than or equal to Vin less than or equal to 5.5V
  • 1.5 microA typical quiescent current
  • 350 mA maximum load capability
  • 1 MHz PWM fixed switching frequency (typ.)
  • Automatic PFM/PWM mode switching
  • Available in fixed output voltages as well as an adjustable version
  • SOT23-5 package
  • Low drop out operation - 100% duty cycle mode
  • Internal synchronous rectification for high efficiency
  • Internal soft start
  • 0.1 microA typical shutdown current
  • Operates from a single Li-Ion cell or 3 cell NIMH/NiCd batteries
  • Only three tiny surface-mount external components required (one inductor, two ceramic capaitors)
  • Current overload protection

Applications:

  • Mobile phones
  • Hand-Held Radios
  • Personal Digital Assistants
  • Palm-top PCs
  • Portable Instruments
  • Battery Powered Devices

Part Number(s)
(NSID)		DescriptionAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM3670MF-2.5EV
Miniature Step-Down DC-DC Converter for Ultra Low Voltage CircuitsFull production


 
DistributorRegionQty
DIGIKEYWorldwide0
NATIONALWorldwide2
$75.00 each1

The LM3670 evaluation board is a working demonstration of a step down DC-DC converter. The application note contains information about the evaluation board. The LM3670 step-down DC-DC converter is optimized for powering ultra-low voltage circuits from a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It provides up to 350 mA load current, over an input voltage range from 2.5V to 5.5V. There are several different fixed voltage output options available as well as an adjustable output voltage version. This device offers superior features and performance for mobile phones and similar portable applications with complex power management systems.

Features:

  • Vout = adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V
  • 2.5V less than or equal to Vin less than or equal to 5.5V
  • 1.5 microA typical quiescent current
  • 350 mA maximum load capability
  • 1 MHz PWM fixed switching frequency (typ.)
  • Automatic PFM/PWM mode switching
  • Available in fixed output voltages as well as an adjustable version
  • SOT23-5 package
  • Low drop out operation - 100% duty cycle mode
  • Internal synchronous rectification for high efficiency
  • Internal soft start
  • 0.1 microA typical shutdown current
  • Operates from a single Li-Ion cell or 3 cell NIMH/NiCd batteries
  • Only three tiny surface-mount external components required (one inductor, two ceramic capaitors)
  • Current overload protection

Applications:

  • Mobile phones
  • Hand-Held Radios
  • Personal Digital Assistants
  • Palm-top PCs
  • Portable Instruments
  • Battery Powered Devices

Part Number(s)
(NSID)		Top ViewTypePinsMSL RatingPeak ReflowRoHSCAD SymbolsModelsPackage
Marking
Format
LM3670MF-2.5/NOPB
LM3670MF-2.5
SOT-2351
1		260
260		RoHSDownloadN/A
SDDB
XTT
LM3670MF-1.2/NOPB
SOT-2351260RoHSDownloadN/A
SCZB
XTT
LM3670MF-1.5/NOPB
SOT-2351260RoHSDownloadN/A
S82B
XTT
LM3670MF-1.6/NOPB
SOT-2351260RoHSDownloadN/A
SDBB
XTT
LM3670MF-1.8/NOPB
LM3670MF-1.8
SOT-2351
1		260
260		RoHSDownloadN/A
SDCB
XTT
LM3670MF-1.875/NOPB
SOT-2351260RoHSDownloadN/A
SEFB
XTT
LM3670MF-3.3/NOPB
LM3670MF-3.3
SOT-2351
1		260
260		RoHSDownloadN/A
SDEB
XTT
LM3670MF-ADJ/NOPB
SOT-2351260RoHSDownloadN/A
SDFB
XTT
LM3670MFX-3.3/NOPB
SOT-2351260RoHSDownloadN/A
SDEB
XTT
LM3670MFX-1.2/NOPB
SOT-2351260RoHSDownloadN/A
SCZB
XTT
LM3670MFX-1.5/NOPB
SOT-2351260RoHSDownloadN/A
S82B
XTT
LM3670MFX-1.6/NOPB
SOT-2351260RoHSDownloadN/A
SDBB
XTT
LM3670MFX-1.8/NOPB
SOT-2351260RoHSDownloadN/A
SDCB
XTT
LM3670MFX-1.875/NOPB
SOT-2351260RoHSDownloadN/A
SEFB
XTT
LM3670MFX-ADJ/NOPB
SOT-2351260RoHSDownloadN/A
SDFB
XTT

Reliability Metrics
Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM3670MF-1.2CMOS70184060010890004309006723
LM3670MF-1.5CMOS70184060010890004309006723
LM3670MF-1.6CMOS70184060010890004309006723
LM3670MF-1.8CMOS70184060010890004309006723
LM3670MF-1.875CMOS70184060010890004309006723
LM3670MF-2.5CMOS70184060010890004309006723
LM3670MF-3.3CMOS70184060010890004309006723
LM3670MF-ADJCMOS70184060010890004309006723
LM3670MFX-1.2CMOS70184060010890004309006723
LM3670MFX-1.5CMOS70184060010890004309006723
LM3670MFX-1.6CMOS70184060010890004309006723
LM3670MFX-1.8CMOS70184060010890004309006723
LM3670MFX-1.875CMOS70184060010890004309006723
LM3670MFX-3.3CMOS70184060010890004309006723
LM3670MFX-ADJCMOS70184060010890004309006723

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.


Obsolete Versions
Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
LM3670MF-2.5
NONE
NATIONAL SEMICONDUCTOR
01 Dec 2009
LM3670MFX-3.3
NONE
NATIONAL SEMICONDUCTOR
01 Dec 2009

[Information as of 22-Nov-2009]