LM3691 - High Accuracy, Miniature 1A, Step-Down DC-DC Converter for Portable Applications from the PowerWise® Family
Datasheet Packaging Samples & Pricing Eval. Boards Knowledge Base

Features
•VOUT = 0.75V to 3.3V
• ±1% DC output voltage precision
•2.3 ≤ VIN ≤ 5.5V
•4 MHz switching frequency
•64 μA (typ.) quiescent current in ECO mode
•1A maximum load capability
•Automatic ECO/PWM mode switching
•Mode Pin to select ECO/Forced PWM mode
•1 μH inductor, 4.7 μF input capacitor (0603(1608) case size) and 4.7 μF output capacitor (0603(1608) case size)
•Current overload and thermal shutdown protections
•Only three tiny surface-mount external components required (solution size less than 15 mm 2)

General Description

The LM3691 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. More...


Applications

•Mobile Phones
•Hand-Held Radios
•MP3 players
•Portable Hard Disk Drives
  Typical Application
*click for larger image

revised typ application diagram

ParametersValues
Output Current 1000 mA
Input Min Voltage 2.3 Volt
Input Max Voltage 5.5 Volt
Output Min 0.75 Volt
Output Max 1.8 Volt
Frequency Min 4000 kHz
Frequency Max 4000 kHz
Efficiency (peak) 95 %
On/Off Pin Yes
Error Flag No
SoftStart Yes
Sync Pin No
Inverting No
Flyback No
RegType Switching Regulator
Temperature Min -30 deg C
Temperature Max 85 deg C
Adjustable Output No
Adj Switch Frequency No
PWM Mode Voltage
Topology Synchronous Buck
Special Features Pin-selectable PWM/ECO mode, Typ. Iq in shutdown is 0.03uA, 1% output accuracy, only 3external components
Step-Down Yes
Multiple Output Capability No
Output Range 0.75V to 1.8V
Switching Frequency 4000 kHz
Feedback Voltage Undefined Volt
Regulator Family Undefined
Automotive No
PowerWise Yes
Synchronous Rectification Yes


Typical Performance

*click for larger image


  Block Diagram
*click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM3691 High Accuracy, Miniature 1A, Step-Down DC-DC Converter for Portable Applications 1897
Kbytes		 20-Jan-09 Download

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Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders		Budgetary PricingStd
Pack
Size		Package
Marking
Format
TypePinsSpec.MSL
Rating		Peak
Reflow		RoHS
Report		CAD
Symbols		WeeksQtyQty$US each
LM3691TL-1.2EVLM3691TL-1.2 Evaluation BoardFull productionN/A
 
Buy Now 		1+$92.001-
6 weeksN/A
LM3691TL-1.8EVLM3691TL-1.8 Evaluation BoardFull productionN/A
 
Buy Now 		1+$92.001-
6 weeksN/A
LM3691TL-0.75MICRO SMD6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now 		1K+$2.00reel
of
250		XV
I V
6 weeksN/A
LM3691TL-1.2MICRO SMD6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now 		1K+$2.00reel
of
250		XV
I X
6 weeksN/A
LM3691TL-1.5MICRO SMD6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now 		1K+$2.00reel
of
250		XV
I Y
6 weeksN/A
LM3691TL-1.8MICRO SMD6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now 		1K+$2.00reel
of
250		XV
I Z
6 weeksN/A
LM3691TL-2.5MICRO SMD6NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now 		1K+$2.00reel
of
250		XV
I 8
12 weeksN/A
LM3691TLX-0.75MICRO SMD6NOPB1260RoHS N/A Full productionN/A
 
Buy Now 		1K+$2.00reel
of
3000		XV
I V
6 weeksN/A
LM3691TLX-1.2MICRO SMD6NOPB1260RoHS N/A Full productionN/A
 
Buy Now 		1K+$2.00reel
of
3000		XV
I X
6 weeksN/A
LM3691TLX-1.5MICRO SMD6NOPB1260RoHS N/A Full productionN/A
 
Buy Now 		1K+$2.00reel
of
3000		XV
I Y
6 weeksN/A
LM3691TLX-1.8MICRO SMD6NOPB1260RoHS N/A Full productionN/A
 
Buy Now 		1K+$2.00reel
of
3000		XV
I Z
6 weeksN/A
LM3691TLX-2.5MICRO SMD6NOPB1260RoHS N/A Full productionN/A
 
Buy Now 		1K+$2.00reel
of
3000		XV
I 8
12 weeksN/A

General Description

The LM3691 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 1A load current, over an input voltage range from 2.3V to 5.5V. There are several different fixed voltage output options available.

LM3691 has a mode-control pin that allows the user to select Forced PWM mode or ECO mode that changes modes between gated PWM mode and PWM automatically depending on the load. In ECO, LM3691 offers superior efficiency and very low Iq under light load conditions. ECO mode extends the battery life through reduction of the quiescent current during light load conditions and system standby.

The LM3691 is available in a 6–bump micro SMD package. Only three external surface-mount components, a 1 μH inductor, a 4.7 μF input capacitor and a 4.7 μF output capacitor, are required.

Application Notes

TitleSize in Kbytes Date Click link below to Download
AN-1772: Application Note 1772 LM3691 Evaluation Board 567
Kbytes		 14-May-08 Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 7-Nov-2009]