National Semiconductor | High-performance Analog

 

 LM26420   
Dual 2.0A, High Frequency Synchronous Step-Down DC-DC Regulator from the PowerWise® Family		 Click link to Download

Features

  • Input voltage range of 3.0V to 5.5V
  • Output voltage range of 0.8V to 4.5V
  • 2.0A output current per output
  • High Switching Frequencies

  •  2.2MHz (LM26420X)

  •  0.55MHz (LM26420Y)
  • 75mΩ PMOS switch
  • 50mΩ NMOS switch
  • 0.8V, 1.5% Internal Voltage Reference
  • Internal soft-start
  • Independent power good for each output
  • Independent precision enable for each output
  • Current mode, PWM operation
  • Thermal Shutdown
  • Over voltage protection
  • Start-up into Pre-biased Output Loads
  • Outputs are 180° out of phase

    • Description

    The LM26420 regulator is a monolithic, high frequency, dual PWM step-down DC/DC converter in a 16 Pin LLP and a 20 Pin eTSSOP package. It provides all the active functions to provide local DC/DC conversion with fast transient response and accurate regulation in the smallest possible PCB area. With a minimum of external components, the LM26420 is easy to use. The ability to drive two 2.0A loads with an internal 75 mΩ PMOS top switch and an internal 50 mΩ NMOS bottom switch using state-of-the-art 0.5 µm BiCMOS technology results in the best power density available. The world-class control circuitry allows on-times as low as 30ns, thus supporting exceptionally high frequency conversion over the entire 3V to 5.5V input operating range down to the minimum output voltage of 0.8V. Switching frequency is internally set to 550 kHz or 2.2 MHz, allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequency is high, efficiencies up to 93% are easy to achieve. External shutdown is included, featuring an ultra-low stand-by current. The LM26420 utilizes current-mode control and internal compensation to provide high-performance regulation over a wide range of operating conditions. Additional features include internal soft-start circuitry to reduce inrush current, pulse-by-pulse current limit, thermal shutdown, power good indicators, precision enables, and output over-voltage protection.


    Applications

  • Local 5V to Vcore Step-Down Converters
  • Core Power in HDDs
  • Set-Top Boxes
  • USB Powered Devices
  • DSL Modems
  • Powering Core and I/O voltages for FPGAs, CPLDs, and ASICs



    • updated image

    Typical Application
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    updated image

    		Block Diagram
    click for larger image



    Typical Performance
    click for larger image


     

    ParametersValues
    Output Current 2000 mA
    Input Min Voltage 3 Volt
    Input Max Voltage 5.5 Volt
    Output Min 0.8 Volt
    Output Max 4.5 Volt
    Frequency Min 1850, 400 kHz
    Frequency Max 700, 2650 kHz
    Efficiency (peak) 95, 94 %
    Integrated Inductor No
    PowerGood / Error Flag Yes
    SoftStart Yes
    Sync Pin No
    Inverting No
    Flyback No
    RegType Switching Regulator
    Temperature Min -40 deg C
    Temperature Max 125 deg C
    Adjustable Output Yes
    Adj Switch Frequency No
    PWM Mode Current Mode Control
    Topology Buck
    Step-Down Yes
    Multiple Output Capability Yes
    Output Range 0.8 - 4.5V
    Switching Frequency 2200, 550 kHz
    Feedback Voltage 0.8 Volt
    On/Off Pin Yes
    Regulator Family SIMPLE SWITCHER
    AEC Q-100 Automotive Grade Undefined
    PowerWise Yes
    Synchronous Rectification Yes

    Datasheets
    TitleSizeDateOther
    Language
    LM26420 Dual 2.0A, High Frequency Synchronous Step-Down DC-DC Regulator621
    Kbytes    		31-Aug-10日本語  


    Application Notes
    TitleSizeDateOther
    Language
    AN-1973: Application Note 1973 Benefits and Challenges of High-Frequency Regulators348
    Kbytes    		25-Jun-09 
    AN-1870: Application Note 1870 LM26420 Evaluation Board429
    Kbytes    		14-Apr-09 

    Part Number(s)
    (NSID)    		Top ViewAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM26420XMH/NOPB


    RoHS Status

    TSSOP EXP PAD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide22
    DIGI-KEYWorldwide221
    FARNELLEurope and Asia143
    MOUSERWorldwide145
    NEWARKAmericas143
    		$2.38 each at 1K+ pcsrail
    of
    73
    LM26420XMHX/NOPB


    RoHS Status

    TSSOP EXP PAD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$2.38 each at 1K+ pcsreel
    of
    2500
    LM26420XSQ/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide915
    AVNET-EMWorldwide1000
    DIGI-KEYWorldwide22
    MOUSERWorldwide905
    TAYLORAmericas915
    		$2.38 each at 1K+ pcsreel
    of
    1000
    LM26420XSQX/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$2.38 each at 1K+ pcsreel
    of
    4500
    LM26420YMH/NOPB


    RoHS Status

    TSSOP EXP PAD    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    AVNET-EMWorldwide143
    DIGI-KEYWorldwide147
    FARNELLEurope and Asia207
    MOUSERWorldwide188
    NEWARKAmericas207
    		$2.28 each at 1K+ pcsrail
    of
    73
    LM26420YMHX/NOPB


    RoHS Status

    TSSOP EXP PAD    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$2.28 each at 1K+ pcsreel
    of
    2500
    LM26420YSQ/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

    Samples
    DistributorRegionQty
    ARROWWorldwide955
    DIGI-KEYWorldwide3431
    MOUSERWorldwide1000
    TAYLORAmericas955
    		$2.28 each at 1K+ pcsreel
    of
    1000
    LM26420YSQX/NOPB


    RoHS Status

    LLP    		Full production
    Lead Time: 6 weeks

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$2.28 each at 1K+ pcsreel
    of
    4500

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM26420.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM26420 is located at RoHS Status.

    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM26420XMHEVAL/NOPB

    		LM26420 2.2 MHz, eTSSOP Synchronous Buck Evaluation BoardFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia4
    MOUSERWorldwide1
    NEWARKAmericas4
    		$85.00 each1

    Description:

    The LM26420 Evaluation board was designed to provide two 2A outputs, VOUT1 and VOUT2 . It is available in either the eTSSOP package option of the LM26420 for easier probing or the LLP version for evaluating the smaller package. The design emphasizes on the compactness of the LM26420 PCB layout and is thermally optimized. The total solution size is less than 35mm by 40mm. The board supports the conversion from an input voltage ranging from 3V to 5.5V down to output voltages of 0.8V for each channel. VOUT1 and VOUT2 are set to 1.2V and 2.5V respectively. The feedback resistor can be changed to support output voltages as low as 0.8V or as high at 4.5V, assuming VIN is high enough to support it. The EN pins are pulled up to VIN by jumpers for easy evaluation but can also be easily controlled by external logic.

    Features:

    • Input Voltage: 3V to 5.5V
    • Output Voltages: 1.2 VOUT1 and 2.5 VOUT2
    • Maximum load current: 2A/output
    • Minimum load current: 0A
    • Size: 1.35 in. x 1.6 in.
    • Peak Current Limit: approx= 3.2A at 25°C
    • Nominal Switching Frequency: 2.2 MHz
    • IC package eTSSOP

    Contents:


    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM26420XSQEVAL/NOPB

    		LM26420 2.2 MHz, LLP Synchronous Buck Evaluation BoardFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    MOUSERWorldwide2
    		$85.00 each1

    Description:

    The LM26420 Evaluation board was designed to provide two 2A outputs, VOUT1 and VOUT2 . It is available in either the eTSSOP package option of the LM26420 for easier probing or the LLP version for evaluating the smaller package. The design emphasizes on the compactness of the LM26420 PCB layout and is thermally optimized. The total solution size is less than 35mm by 40mm. The board supports the conversion from an input voltage ranging from 3V to 5.5V down to output voltages of 0.8V for each channel. VOUT1 and VOUT2 are set to 1.2V and 2.5V respectively. The feedback resistor can be changed to support output voltages as low as 0.8V or as high at 4.5V, assuming VIN is high enough to support it. The EN pins are pulled up to VIN by jumpers for easy evaluation but can also be easily controlled by external logic.

    Features:

    • Input Voltage: 3V to 5.5V
    • Output Voltages: 1.2 VOUT1 and 2.5 VOUT2
    • Maximum load current: 2A/output
    • Minimum load current: 0A
    • Size: 1.35 in. x 1.6 in.
    • Peak Current Limit: approx= 3.2A at 25°C
    • Nominal Switching Frequency: 2.2 MHz
    • IC package LLP

    Contents:


    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM26420YMHEVAL/NOPB

    		LM26420 550 kHz, eTSSOP Synchronous Buck Evaluation BoardFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    FARNELLEurope and Asia5
    MOUSERWorldwide1
    NEWARKAmericas5
    		$85.00 each1

    Description:

    The LM26420 Evaluation board was designed to provide two 2A outputs, VOUT1 and VOUT2 . It is available in either the eTSSOP package option of the LM26420 for easier probing or the LLP version for evaluating the smaller package. The design emphasizes on the compactness of the LM26420 PCB layout and is thermally optimized. The total solution size is less than 35mm by 40mm. The board supports the conversion from an input voltage ranging from 3V to 5.5V down to output voltages of 0.8V for each channel. VOUT1 and VOUT2 are set to 1.2V and 2.5V respectively. The feedback resistor can be changed to support output voltages as low as 0.8V or as high at 4.5V, assuming VIN is high enough to support it. The EN pins are pulled up to VIN by jumpers for easy evaluation but can also be easily controlled by external logic.

    Features:

    • Input Voltage: 3V to 5.5V
    • Output Voltages: 1.2 VOUT1 and 2.5 VOUT2
    • Maximum load current: 2A/output
    • Minimum load current: 0A
    • Size: 1.35 in. x 1.6 in.
    • Peak Current Limit: approx= 3.2A at 25°C
    • Nominal Switching Frequency: 550 kHz
    • IC package eTSSOP

    Contents:


    Part Number(s)
    (NSID)    		DescriptionAvailabilityCurrent Reported StockBudgetary PricingPack
    Size
    LM26420YSQEVAL/NOPB

    		LM26420 550 kHz, LLP Synchronous Buck Evaluation BoardFull production
    Lead Free (RoHS)

     
    DistributorRegionQty
    DIGI-KEYWorldwide0
    		$85.00 each1

    Description:

    The LM26420 Evaluation board was designed to provide two 2A outputs, VOUT1 and VOUT2. It is available in either the eTSSOP package option of the LM26420 for easier probing or the LLP version for evaluating the smaller package. The design emphasizes on the compactness of the LM26420 PCB layout and is thermally optimized. The total solution size is less than 35mm by 40mm. The board supports the conversion from an input voltage ranging from 3V to 5.5V down to output voltages of 0.8V for each channel. VOUT1 and VOUT2 are set to 1.2V and 2.5V respectively. The feedback resistor can be changed to support output voltages as low as 0.8V or as high at 4.5V, assuming VIN is high enough to support it. The EN pins are pulled up to VIN by jumpers for easy evaluation but can also be easily controlled by external logic.

    Features:

    • Input Voltage: 3V to 5.5V
    • Output Voltages: 1.2 VOUT1 and 2.5 VOUT2
    • Maximum load current: 2A/output
    • Minimum load current: 0A
    • Size: 1.35 in. x 1.6 in.
    • Peak Current Limit: approx= 3.2A at 25°C
    • Nominal Switching Frequency: 550 kHz
    • IC package LLP

    Contents:

    • LM26420 LLP evaluation board
    • LM26420 datasheet
    • AN-1870 - Application Note 1870 LM26420 Evaluation Board



    National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C1) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/en/packaging/greennopb.html. Lead free products are RoHS compliant.

    Lead Free product status is available through the search tool located here

    Part Number(s)
    (NSID)    		Weight
    (milligrams)    		TypePinsMSL RatingPeak ReflowRoHS
    Status    		CAD SymbolsModelsPackage
    Marking
    Format
    LM26420XMH/NOPB

    		73.061
    		TSSOP EXP PAD201260DetailDownloadN/A
    		NSUZXYTT
    LM26420
    XMH
    LM26420XMHX/NOPB

    		73.061
    		TSSOP EXP PAD201260DetailDownloadN/A
    		NSUZXYTT
    LM26420
    XMH
    LM26420XSQ/NOPB

    		39.461
    		LLP163260DetailDownloadN/A
    		NS
    UZXYTT
    L26420X
    LM26420XSQX/NOPB

    		39.461
    		LLP163260DetailDownloadN/A
    		NS
    UZXYTT
    L26420X
    LM26420YMH/NOPB

    		73.061
    		TSSOP EXP PAD201260DetailDownloadN/A
    		NSUZXYTT
    LM26420
    YMH
    LM26420YMHX/NOPB

    		73.061
    		TSSOP EXP PAD201260DetailDownloadN/A
    		NSUZXYTT
    LM26420
    YMH
    LM26420YSQ/NOPB

    		39.461
    		LLP163260DetailDownloadN/A
    		NS
    UZXYTT
    L26420Y
    LM26420YSQX/NOPB

    		39.461
    		LLP163260DetailDownloadN/A
    		NS
    UZXYTT
    L26420Y

    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM26420.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM26420 is located at RoHS Status.

    CAD Symbols and Models
    Download LM26420 CAD Symbols
    		 Models
    N/A


    Reliability Metrics
    Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
    LM26420XMHPVIP0500142800017550003497986041
    LM26420XMHXPVIP0500142800017550003497986041
    LM26420XSQPVIP0500142800017550003497986041
    LM26420XSQXPVIP0500142800017550003497986041
    LM26420YMHPVIP0500142800017550003497986041
    LM26420YMHXPVIP0500142800017550003497986041
    LM26420YSQPVIP0500142800017550003497986041
    LM26420YSQXPVIP0500142800017550003497986041

    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.


    All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

    Moisture Sensitivity Level Data for LM26420.

    A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

    National's certificate of product compliance for LM26420 is located at RoHS Status.

    Power for Space-Constrained Applications
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    Power for Space-Constrained Applications
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    Power for Space-Constrained Applications
    Date: 2009-04-22
    Length: 0:03:35
    Power for Space-Constrained Applications
    Date: 2009-04-22
    Length: 00:45:00
    [Information as of 8-Feb-2012]
    Copyright © 2011 National Semiconductor Corporation