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LM2623 -
General Purpose, Gated Oscillator Based, DC/DC Boost Converter
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Features
| • | Good Efficiency Over a Very Wide Load Range |
| • | Very Low Output Voltage Ripple |
| • | Small, Mini-SO-8 Package (Half the Footprint of Standard 8 pin SO Package) |
| • | 1.09 mm Package Height |
| • | Up to 2 MHz Switching Frequency |
| • | .8V to 14V Operating Voltage |
| • | 1.1V Start-up Voltage |
| • | 1.24V - 14V Adjustable Output Voltage |
| • | Up to 2A Load Current at low Output Voltages |
| • | 0.17 Internal MOSFET |
| • | Up to 90% Regulator Efficiency |
| • | 80 µA Typical Operating Current (into VDD pin of supply) |
| • | <2.5µA Guaranteed Supply Current In Shutdown |
| • | 4mm x 4mm Thermally Enhanced LLP Package Option |
General Description
The LM2623 is a high efficiency, general purpose, step-up DC-DC switching regulator for battery-powered and low input voltage systems. More...
Applications
| • | Cameras, Pagers and Cell Phones |
| • | PDAs,Palmtop Computers, GPS devices |
| • | White LED Drive, TFT or Scanned LCDs |
| • | Flash Memory Programming |
| • | Hand-Held Instruments |
| • | 1, 2, 3 or 4 Cell Alkaline Systems |
| • | 1, 2 or 3 Cell Lithium-ion Systems |
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Typical Application
click for larger image
| Parameters | Values |
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| Output Range |
1.24V to 14V |
| Switch Current |
1.2, 2.2 Amp |
| Input Min Voltage |
0.8 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 |
Ratio-adaptive 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 |
| PowerWise |
No |
Typical Performance
click for larger image
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Also Recommended
| LM2731▲ | 40V/1A Internal Switch, SOT-23, PWM Boost Regulator |
| LM3224▲ | Higher Efficiency, Pin Selectable PWM Frequency Allowing Easy Filtering And Low Noise |
Additional Resources
Application Notes
Connection Diagram
click for larger image
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Datasheet
Package Availability, Models, Samples & Pricing
| Obsolete Part | Alternate Part or
Supplier | Source | Last Time Buy Date |
LM2623A MDC
| NONE
| NATIONAL SEMICONDUCTOR
| 03 Dec 2008
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LM2623A MWC
| NONE
| NATIONAL SEMICONDUCTOR
| 03 Dec 2008
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LM2623ALDX
| NONE
| NATIONAL SEMICONDUCTOR
| 16 Nov 2008
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General Description
The LM2623 is a high efficiency, general purpose, step-up DC-DC switching regulator for battery-powered and low input voltage systems. It accepts an input voltage between .8 and 14 volts and converts it into a regulated output voltage between 1.24 and 14 volts. Efficiencies up to 90% are achievable with the LM2623.
In order to adapt to a number of applications, the LM2623 allows the designer to vary the output voltage, the operating frequency (300kHz to 2 MHz) and duty cycle (17% to 90%) to optimize the part's performance. The selected values can be fixed or can vary with battery voltage or input to output voltage ratio. The LM2623 uses a very simple, on/off regulation mode to produce good efficiency and stable operation over a wide operating range. It normally regulates by skipping switching cycles when it reaches the regulation limit (Pulse Frequency Modulation).
Note: Please read the "Non-Linear Effect" and "Choosing The Correct C3 Capacitor" sub-sections of the Design Procedure section of this data sheet, so that any challenges with designing with this part can be taken into account before a board design/layout is finalized.
For Alternative Solutions, See Also: LM2700, LM2622, LM2731, LM2733, and LM2621.
Reliability Metrics
| Part Number |
Process |
EFR Reject |
EFR Sample Size |
PPM |
LTA Rejects |
LTA Device Hours |
FITS |
MTTF (Hours) |
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LM2623ALD | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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LM2623AMM | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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LM2623AMMX | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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LM2623LD | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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LM2623LDX | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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LM2623MM | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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LM2623MMX | ABCD150 | 0 | 34175 | 0 | 0 | 4234000 | 1 | 1201409060
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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.
Reference Designs
Application Notes
| Title | Size in Kbytes |
Date |
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| AN-1274: Application Note 1274 LM2623 Evaluation Board |
636
Kbytes |
21-Sep-05 |
Download |
AN-1274 (Chinese): Application Note 1274 LM2623 Evaluation Board
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208 Kbytes |
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| AN-1221: Application Note 1221 LM2623 Cookbook |
35
Kbytes |
2-May-04 |
Download |
AN-1221 (Japanese): Application Note 1221 LM2623 Cookbook
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60 Kbytes |
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| AN-1258: Application Note 1258 National`s LM2623 Boost Converter - A Simple Supply |
64
Kbytes |
2-May-04 |
Download |
More Application Notes
| Title | Size in Kbytes |
Date |
|
| 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-1198: Application Note 1198 LM2622 Step-Up DC/DC Converter Evaluation Board |
110
Kbytes |
3-Apr-07 |
Download |
[Information as of 7-Nov-2009]
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