SLUSFV7 November   2024 LMR51403

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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 Typical Characteristics
  8. 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 Control
      2. 7.3.2 Adjustable Output Voltage
      3. 7.3.3 Enable
      4. 7.3.4 Minimum ON Time, Minimum OFF Time, and Frequency Foldback
      5. 7.3.5 Bootstrap Voltage
      6. 7.3.6 Overcurrent and Short-Circuit Protection
      7. 7.3.7 Soft Start
      8. 7.3.8 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 CCM Mode
      4. 7.4.4 Light Load Operation (PFM Version)
      5. 7.4.5 Light-Load Operation (FPWM Version)
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      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 Inductor Selection
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Input Capacitor Selection
        7. 8.2.2.7 Bootstrap Capacitor
        8. 8.2.2.8 Undervoltage Lockout Setpoint
        9. 8.2.2.9 Replacing Non Sync Buck Converter
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Compact Layout for EMI Reduction
        2. 8.4.1.2 Feedback Resistors
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
        1. 9.1.2.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

6.5 Electrical Characteristics

Limits apply over operating junction temperature (TJ) range of –40°C to +150°C, unless otherwise stated. Minimum and Maximum limits(1) are specified through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated, the following conditions apply: VIN = 4V to 42V.
PARAMETER PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY
IQ(VIN) VIN quiescent current (3) VEN = 3V, FPWM operation 420 µA
IQ(VIN) VIN quiescent current (non-switching)(2) VEN = 3V, PFM variant only 26.5 40 µA
ISUPPLY Input supply current when in
regulation(3)		 VIN = 24V, VOUT = 5V, IOUT = 0A,
RFBB = 22.1kΩ, PFM variant		 38 µA
ISD(VIN) VIN shutdown supply current VEN = 0V 0.8 3 µA
UVLO
VIN_UVLO(R) VIN UVLO rising threshold VIN rising 3.82 4 V
VIN_UVLO(F) VIN UVLO falling threshold  VIN falling 3.4 3.56 V
VIN_UVLO(H) VIN UVLO hysteresis 0.25 V
ENABLE
VEN(R) EN voltage rising threshold EN rising, enable switching 1.1 1.227 1.36 V
VEN(F) EN voltage falling threshold EN falling, disable switching 0.85 1.0 1.15 V
IEN(P2) EN pin sourcing current post EN rising threshold VEN = 3V 10 50 nA
REFERENCE VOLTAGE
VFB Reference voltage 0.788 0.8 0.812 V
IFB(LKG) FB input leakage current VFB = 0.8V 0.2 nA
SWITCHING FREQUENCY
fSW(CCM) Switching frequency, CCM operation "X" Version 340 400 460 KHz
fSW(CCM) Switching frequency, CCM operation "Y" Version 0.935 1.1 1.265 MHz
STARTUP
tSS Internal fixed soft-start time 2.3 ms
POWER STAGE
RDSON(HS) High-side MOSFET on-resistance VIN = 12V, TJ = 25°C 0.7 Ω
RDSON(LS) Low-side MOSFET on-resistance VIN = 12V, TJ = 25°C 0.36 Ω
tON_MIN Minimum ON pulse width VIN = 12V, IOUT = 0.1A 80 ns
tON_MAX Maximum ON pulse width VIN = 12V, IOUT = 0.3A 5 µs
tOFF_MIN Minimum OFF pulse width VIN = 5V 200 ns
CURRENT LIMITS AND HICCUP
IHS_PK(OC) High-side peak current limit  LMR51403 0.4 0.55 0.7 A
ILS_V(OC) Low-side valley current limit  LMR51403 0.32 0.42 0.51 A
ILS(NOC) Low-side negative current limit LMR51403 FPWM Only –0.27 A
IZC Zero-cross detection current threshold (3) 0 A
VHICCUP FB pin voltage required to trip shortcircuit hiccup mode(3) 0.32 V
THERMAL SHUTDOWN
TJ(SD) Thermal shutdown threshold (3) Junction temperature rising 165 °C
TJ(HYS) Thermal shutdown hysteresis (3) 20 °C
(1) MIN and MAX limits are 100% production tested at 25℃. Limits over the operating temperature range verified through correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate Average Outgoing Quality Level (AOQL).
(2) This is the current used by the device open loop, it does not represent the total input current of the system when in regulation.
(3) Not production tested. Specified by correlation by design.