SNVSAA2B July   2015  – July 2017 LM46002-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed Frequency Peak Current Mode Controlled Step-Down Regulator
      2. 7.3.2  Light Load Operation
      3. 7.3.3  Adjustable Output Voltage
      4. 7.3.4  Enable (ENABLE)
      5. 7.3.5  VCC, UVLO and BIAS
      6. 7.3.6  Soft-Start and Voltage Tracking (SS/TRK)
      7. 7.3.7  Switching Frequency (RT) and Synchronization (SYNC)
      8. 7.3.8  Minimum ON-Time, Minimum OFF-Time and Frequency Foldback at Dropout Conditions
      9. 7.3.9  Internal Compensation and CFF
      10. 7.3.10 Bootstrap Voltage (BOOT)
      11. 7.3.11 Power Good (PGOOD)
      12. 7.3.12 Overcurrent and Short-Circuit Protection
      13. 7.3.13 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Stand-by Mode
      3. 7.4.3 Active Mode
      4. 7.4.4 CCM Mode
      5. 7.4.5 Light Load Operation
      6. 7.4.6 Self-Bias Mode
  8. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Output Voltage Setpoint
        3. 8.2.2.3  Switching Frequency
        4. 8.2.2.4  Input Capacitors
        5. 8.2.2.5  Inductor Selection
        6. 8.2.2.6  Output Capacitor Selection
        7. 8.2.2.7  Feed-Forward Capacitor
        8. 8.2.2.8  Bootstrap Capacitors
        9. 8.2.2.9  VCC Capacitor
        10. 8.2.2.10 BIAS Capacitors
        11. 8.2.2.11 Soft-Start Capacitors
        12. 8.2.2.12 Undervoltage Lockout Setpoint
        13. 8.2.2.13 PGOOD
      3. 8.2.3 Application Performance Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Compact Layout for EMI Reduction
      2. 10.1.2 Ground Plane and Thermal Considerations
      3. 10.1.3 Feedback Resistors
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • Qualified for Automotive Applications
  • AEC-Q100 Qualified With the Following Results:
    • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature
  • 27-µA Quiescent Current in Regulation
  • High Efficiency at Light Load (DCM and PFM)
  • Tested to EN55022/CISPR 22 EMI standards
  • Integrated Synchronous Rectification
  • Adjustable Frequency Range: 200 kHz to 2.2 MHz (500-kHz default)
  • Frequency Synchronization to External Clock
  • Internal Compensation
  • Stable With Almost Any Combination of Ceramic, Polymer, Tantalum, and Aluminum Capacitors
  • Power-Good Flag
  • Soft Start into Pre-Biased Load
  • Internal and Adjustable External Soft Start
  • Output Voltage Tracking Capability
  • Precision Enable to Program System UVLO
  • Output Short-Circuit Protection With Hiccup Mode
  • Overtemperature Thermal Shutdown Protection
  • Create a Custom Design Using the LM46002-Q1 With the WEBENCH® Power Designer

2 Applications

  • Sub-AM Band 12-V and 24-V Automotive
  • Telecommunications Systems
  • Commercial Vehicle Power Supplies
  • General Purpose Wide VIN Regulation
  • High Efficiency Point-Of-Load Regulation

3 Description

The LM46002-Q1 regulator is an easy-to-use synchronous step-down DC-DC converter capable of driving up to 2 A of load current from an input voltage ranging from 3.5 V to 60 V. The LM46002-Q1 provides exceptional efficiency, output accuracy and drop-out voltage in a very small solution size. An extended family is available in various load-current options and 36-V maximum input voltage. The device is pin-to-pin compatible package with LM4360x and LM4600x family. Peak-current-mode control is employed to achieve simple control-loop compensation and cycle-by-cycle current limiting. Optional features such as programmable switching frequency, synchronization, power-good flag, precision enable, internal soft-start, extendable soft-start, and tracking provide a flexible and easy-to-use platform for a wide range of applications. Discontinuous conduction and automatic frequency reduction at light loads improve light load efficiency. The family requires few external components. Pin arrangement allows simple, optimum PCB layout. Protection features include thermal shutdown, VCC undervoltage lockout, cycle-by-cycle current limit, and output short-circuit protection. The LM46002A-Q1 version is optimized for PFM operation and recommended for new designs. The LM46002-Q1 device is available in the 16-lead HTSSOP (PWP) package (6.6 mm × 5.1 mm × 1.2 mm) with 0.65-mm lead pitch.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM46002-Q1 HTSSOP (16) 6.60 mm × 5.10 mm
LM46002A-Q1 HTSSOP (16) 6.60 mm × 5.10 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

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Simplified Schematic

LM46002-Q1 LM46002A-Q1 sch_basic01_snvsaa2_front.gif

Radiated Emission Graph
VIN = 24 V, VOUT = 3.3 V, FS = 500 kHz, IOUT = 2 A

LM46002-Q1 LM46002A-Q1 EMI_Radiated_24V_5V_0p5MHz.png