LM2621 - Low Input Voltage, Step-Up DC-DC

Datasheet Packaging Samples & Pricing Eval. Boards Reliability Design Tools Reference Designs Application Notes Knowledge Base

Features
Small Mini-SO8 Package (Half the Footprint of Standard 8-Pin SO Package)
1.09 mm Package Height
Up to 2 MHz Switching Frequency
1.2V to 14V Input Voltage
1.24V - 14V Adjustable Output Voltage
Up to 1A Load Current
0.17 Internal MOSFET
Up to 90% Regulator Efficiency
80 µA Typical Operating Current
<2.5µA Guaranteed Supply Current In Shutdown

General Description


The LM2621 is a high efficiency, step-up DC-DC switching regulator for battery-powered and low input voltage systems. More...


Applications


PDAs, Cellular Phones
2-Cell and 3-Cell Battery-Operated Equipment
PCMCIA Cards, Memory Cards
Flash Memory Programming
TFT/LCD Applications
3.3V to 5.0V Conversion
GPS Devices
Two-Way Pagers
Palmtop Computers
Hand-Held Instruments
  Typical Application
click for larger image


Parametric Table     expand
Parametric Table    collapse
Output Range 1.24V to 14V
Switch Current 2.85 Amp
Input Min Voltage 1.2 Volt
Input Max Voltage 14 Volt
Frequency Max 2000 kHz
Output Min 1.24 Volt
Output Max 14 Volt
Output Range 1.24V to 14V
Switch Current 2.85 Amp
Input Min Voltage 1.2 Volt
Input Max Voltage 14 Volt
Frequency Max 2000 kHz
Output Min 1.24 Volt
Output Max 14 Volt
Efficiency (peak) 90 %
Sync Pin No
Adj Switch Frequency Yes
Frequency Min 300 kHz
On/Off Pin Yes
Error Flag No
SoftStart No
Special Features Constant duty cycle gated oscillator
PWM Mode Gated Oscillator
Topology Boost, Flyback
Step-Up Yes
Inverting No
Flyback Yes
RegType Switching Regulator
Adjustable Output Yes
Output Power Undefined Watt
Temperature Min -40 deg C
Temperature Max 85 deg C
View Using Catalog


Typical Performance


click for larger image


  WEBENCH Live Simulation!
WEBENCH® Designer

LM2621

 
1.20 <=
V in Lower
 V
 
<=
V in Upper
 V
 
<= 14.00
V out 1.24 <=  V <= 14.00
I out    A <= 2.85
Ambient Temperature  °C <= 100


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Also Recommended
LM2623Operates With Input Voltages As Low As 0.8V
LM2698Wider Switch Voltage , Fixed Frequency
LM27313Fixed Frequency , Smaller Package
LM27331A 40V Switch Boost Regulator In SOT-23
LM3224Wider Switch Voltage , Fixed Frequency
LM2704Low Power 500mA Switch Boost In SOT-23

Additional Resources


Design Tools (see below)

Application Notes (see below)


Connection Diagram


click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM2621 Low Input Voltage, Step-Up DC-DC Converter 656 Kbytes 25-Mar-05 Download
LM2621 Low Input Voltage, Step-Up DC-DC Converter (Japanese)
372 Kbytes   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
LM2621EVALLow Input Voltage, Step-Up DC-DCFull productionN/A
 
Buy Now
1+$30.001-
8 weeksN/A
LM2621MMMINI SOIC8STD
NOPB
1
1
260
260
RoHS Download Full productionN/A
Samples
Buy Now
1K+$0.71reel
of
1000
ZXTT
S06A
6 weeks2000
LM2621MMXMINI SOIC8STD
NOPB
1
1
260
260
RoHS Download Full productionN/A
 
Buy Now
1K+$0.71reel
of
3500
ZXTT
S06A
12 weeks5000

General Description


The LM2621 is a high efficiency, step-up DC-DC switching regulator for battery-powered and low input voltage systems. It accepts an input voltage between 1.2V and 14V and converts it into a regulated output voltage. The output voltage can be adjusted between 1.24V and 14V. It has an internal 0.17 N-Channel MOSFET power switch. Efficiencies up to 90% are achievable using the LM2621.

The high switching frequency (adjustable up to 2MHz) of the LM2621 allows for tiny surface mount inductors and capacitors. Because of the unique constant-duty-cycle gated oscillator topology very high efficiencies are realized over a wide load range. The supply current is reduced to 80µA because of the BiCMOS process technology. In the shutdown mode, the supply current is less than 2.5µA.

The LM2621 is available in a Mini-SO-8 package. This package uses half the board area of a standard 8-pin SO and has a height of just 1.09 mm.

Reliability Metrics


Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM2621MMABCD15003152000373900011060951459
LM2621MMXABCD15003152000373900011060951459

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.


Design Tools


TitleSize in Kbytes Date Click link below to Download    
Power Reference Design Library 0 Kbytes 28-Mar-2006 View    

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Reference Designs
LM2621 Reference Design - Sepic Converter for Battery Applications: 2.7-5.5V Input, 3.3V @ 0.65A Output

More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1274: Application Note 1274 LM2623 Evaluation Board 636 Kbytes 21-Sep-05 Download
AN-1274 (Chinese): Application Note 1274 LM2623 Evaluation Board
208 Kbytes  
AN-1250: Application Note 1250 Inductive Based Switching Regulator Circuits Provide High Efficiency White LED Drives 81 Kbytes 26-Sep-02 Download
AN-1237: Application Note 1237 RSDS™ Flat Panel Display Design Guidelines Part 2 141 Kbytes 14-May-03 Download
AN-1258: Application Note 1258 National`s LM2623 Boost Converter - A Simple Supply 64 Kbytes 2-May-04 Download
AN-1221: Application Note 1221 LM2623 Cookbook 35 Kbytes 2-May-04 Download
AN-1221 (Japanese): Application Note 1221 LM2623 Cookbook
60 Kbytes   Download
AN-1198: Application Note 1198 LM2622 Step-Up DC/DC Converter Evaluation Board 110 Kbytes 3-Apr-07 Download

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[Information as of 3-Jul-2009]