LM22678   
5A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Precision Enable 		Click link to Download

Features

•Wide input voltage range: 4.5V to 42V
•Internally compensated voltage mode control
•Stable with low ESR ceramic capacitors
•100 mΩ N-channel MOSFET
•Output voltage options:
• -ADJ (outputs as low as 1.285V)
• -5.0 (output fixed to 5V)
•±1.5% feedback reference accuracy
•Switching frequency of 500 kHz
•-40°C to 125°C operating junction temperature range
•Precision enable pin
•Integrated boot diode
•Integrated soft-start
•Fully WEBENCH ® enabled
•Step-down and inverting buck-boost applications

Description

The LM22678 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 5A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance N-channel MOSFET. The series consists of a fixed 5V output and an adjustable version.

The SIMPLE SWITCHER ® concept provides for an easy to use complete design using a minimum number of external components and National’s WEBENCH ® design tool. National’s WEBENCH ® tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in. The switching clock frequency is provided by an internal fixed frequency oscillator which operates at 500 kHz. The LM22678 series also has built in thermal shutdown, current limiting and an enable control input that can power down the regulator to a low 25 µA quiescent current standby condition.

Applications
•Industrial Control
•Telecom and Datacom Systems
•Embedded Systems
•Automotive Telematics and Body Electronics
•Conversions from Standard 24V, 12V and 5V Input Rails
WEBENCH Power Designer My Designs

LM22678
 
4.50 <=		 V in Lower
 V		  
<=		 V in Upper
 V		  
<= 42.00
V out 1.28 <=  V <= 37.00
I out    A <= 5.00
Ambient Temperature  °C <= 100


What are WEBENCH® tools?

Also Recommended
LM22674▲0.5A Version
LM22675▲1A Version
LM22676▲3A Version
LM22677▲Features Adjustable Switching Frequency Or Frequency Sync Up To 1MHz And Precision Enable
LM22679▲Features Adjustable Soft-Start And Adjustable Current Limit
LM22680▲2A Version
LM3150▲Synchronous Simple Switcher Controller For Higher Efficiency



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                                              LM22678
Drag-Select for Table Reset Graph
Also Recommended
LM22674▲0.5A Version
LM22675▲1A Version
LM22676▲3A Version
LM22677▲Features Adjustable Switching Frequency Or Frequency Sync Up To 1MHz And Precision Enable
LM22679▲Features Adjustable Soft-Start And Adjustable Current Limit
LM22680▲2A Version
LM3150▲Synchronous Simple Switcher Controller For Higher Efficiency

Typical Application
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Connection Diagram
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Typical Performance
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Paramaters / ValuesLM22678 LM22674 LM22675 LM22676 LM22677 LM22679 LM22680 LM3150
Output Current5000 mA 500 mA 1000 mA 3000 mA 5000 mA 5000 mA 2000 mA 12000 mA
Input Min Voltage4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 4.5 Volt 6 Volt
Input Max Voltage42 Volt 42 Volt 42 Volt 42 Volt 42 Volt 42 Volt 42 Volt 42 Volt
Output Min1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt
Efficiency (peak)92 % 91 % 92 % 92 % 92 % 92 % 89 % 95 %
On/Off PinYes Yes Yes Yes Yes No Yes Yes
Error FlagNo No No No No No No No
SoftStartNo No No No No Yes Yes Yes
Sync PinNo No No No Yes No Yes No
InvertingYes Yes Yes Yes Yes Yes No
FlybackNo No No No No No No No
RegTypeSwitching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Regulator Switching Controller
Temperature Min-40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C -40 deg C
Temperature Max125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C 125 deg C
Adjustable OutputYes Yes Yes Yes Yes Yes Yes Yes
Adj Switch FrequencyNo No No No Yes No Yes Yes
PWM ModeVoltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control Voltage Mode Control
TopologyBuck Buck Buck Buck Buck Buck Buck Step-Down/Buck
Special Features500 kHz Switching Frequency 500 kHz Default Switching Frequency, 500 kHz Switching Frequency 500 kHz Switching Frequency 500 kHz Switching Frequency 500 kHz Default Switching Frequency Adjustable Current Limit
Step-DownYes Yes Yes Yes Yes Yes Yes Yes
Multiple Output CapabilityNo No No No No No No No
Switching Frequency500 kHz 500 kHz 500 kHz 500 kHz 500 kHz 500 kHz 500 kHz
Feedback Voltage1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 1.285 Volt 0.6 Volt
Regulator FamilySIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER SIMPLE SWITCHER
AutomotiveNo No No No No No
PowerWiseNo No No No No No No Yes
Synchronous RectificationNo No No No No No No Yes

Datasheet
TitleSizeDateOther
Language
LM22678 5A SIMPLE SWITCHER®, Step-Down Voltage Regulator with Precision Enable504
Kbytes		24-Nov-08日本語


Featured Application Notes
TitleSizeDateOther
Language
AN-1930: Application Note 1930 SIMPLE SWITCHER® Regulators Take Over Automotive Applications85
Kbytes		7-Jan-09 
AN-1889: Application Note 1889 How to Measure the Loop Transfer Function of Power Supplies612
Kbytes		14-Oct-08 


More Application Notes
TitleSizeDateOther
Language
AN-1888: Application Note 1888 LM22670 Evaluation Board Inverting Topology and Application Notes1020
Kbytes		9-Jul-09日本語
AN-1895: Application Note 1895 LM22671 Evaluation Board249
Kbytes		14-Oct-08 
AN-1896: Application Note 1896 LM22672 Evaluation Board258
Kbytes		14-Oct-08 
AN-1891: Application Note 1891 LM22679 Evaluation Board232
Kbytes		14-Oct-08 
AN-1894: Application Note 1894 LM22673 Evaluation Board255
Kbytes		14-Oct-08 
AN-1892: Application Note 1892 LM22677 Evaluation Board237
Kbytes		14-Oct-08日本語
AN-1885: Application Note 1885 LM22670 Evaluation Board499
Kbytes		14-Oct-08 

Part Number(s)
(NSID)		Top ViewAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM22678TJE-5.0/NOPB

RoHS



TO-263 THIN		Full production
Lead Time: 16 weeks

Samples
DistributorRegionQty
ARROWWorldwide1500
DIGIKEYWorldwide916
FUTUREWorldwide250
NEWARKAmericas98
$3.25 each at 1K+ pcsreel
of
250
LM22678TJE-ADJ/NOPB

RoHS



TO-263 THIN		Full production
Lead Time: 16 weeks

Samples
DistributorRegionQty
ARROWWorldwide2500
DIGIKEYWorldwide349
FUTUREWorldwide400
NEWARKAmericas154
$3.25 each at 1K+ pcsreel
of
250
LM22678TJ-5.0/NOPB

RoHS



TO-263 THIN		Full production
Lead Time: 16 weeks

 
DistributorRegionQty
ARROWWorldwide1000
DIGIKEYWorldwide0
$3.25 each at 1K+ pcsreel
of
1000
LM22678TJ-ADJ/NOPB

RoHS



TO-263 THIN		Full production
Lead Time: 16 weeks

 
DistributorRegionQty
DIGIKEYWorldwide0
$3.25 each at 1K+ pcsreel
of
1000

Part Number(s)
(NSID)		DescriptionAvailabilityCurrent Reported StockBudgetary PricingStandard Pack Size
LM22677EVAL
Evaluation Board for LM22677 & LM22678, 5A SIMPLE SWITCHER regulators with Adj Vout, Adj Freq or Freq Synch & Precision EnableFull production


 
DistributorRegionQty
AVNET-EMWorldwide2
DIGIKEYWorldwide18
FUTUREWorldwide2
NATIONALWorldwide14
$24.00 each1

Description:

The LM22677 evaluation board is designed to demonstrate the capabilities of the LM22677 switching regulator. The LM22677 evaluation board is configured to provide an output voltage of 3.3V up to 5A load current with an input voltage range of 4.5V to 42V. Due to the low RDS(ON) of the integrated N-channel MOSFET and maximum duty-cycle limitations, the minimum input voltage of 4.5V will only provide a 3.3V output voltage for load currents up to 500 mA. At 5.5V input voltage 3A of output current is possible while maintaining 3.3V of output voltage. For load currents higher than 3A, in input voltage of 6.5V or higher is required. The typical operating frequency is 500 kHz. The evaluation board is designed to operate at ambient temperatures up to 30 °C.

Features:

  • Input Range: 4.5V to 42V
  • Output Voltage: 3.3V
  • Output Current Range: 0A to 5A
  • Frequency of Operation: 500 kHz
  • Board Size: 2 X 2 inches
  • Package: TO-263 THIN

At low input voltages between 4.5V and 6V, a minimum load of approximately 5 mA may be required to reach a regulated 3.3V output voltage. To aid in the design and evaluation of DC/DC buck converter solutions based on the LM22677 switching regulator, the evaluation board can be re-configured for different output voltages.

Contents:


Part Number(s)
(NSID)		Top ViewTypePinsMSL RatingPeak ReflowRoHSCAD SymbolsModelsPackage
Marking
Format
LM22678TJE-5.0/NOPB
TO-263 THIN71260RoHSN/AN/A
NSUZXYTTE#
LM22678
TJ-5.0
LM22678TJE-ADJ/NOPB
TO-263 THIN71260RoHSN/AN/A
NSUZXYTTE#
LM22678
TJ-ADJ
LM22678TJ-5.0/NOPB
TO-263 THIN71260RoHSN/AN/A
NSUZXYTTE#
LM22678
TJ-5.0
LM22678TJ-ADJ/NOPB
TO-263 THIN71260RoHSN/AN/A
NSUZXYTTE#
LM22678
TJ-ADJ

Reliability Metrics
Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM22678TJ-5.0ABCD5053640016269843461661152
LM22678TJ-ADJABCD5053640016269843461661152
LM22678TJE-5.0ABCD5053640016269843461661152
LM22678TJE-ADJABCD5053640016269843461661152

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.


[Information as of 20-Nov-2009]