SNVSBZ3 June   2021 LM5168-Q1

ADVANCE INFORMATION  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Control Architecture
      2. 8.3.2  Internal VCC Regulator and Bootstrap Capacitor
      3. 8.3.3  Internal Soft Start
      4. 8.3.4  On-Time Generator
      5. 8.3.5  Current Limit
      6. 8.3.6  N-Channel Buck Switch and Driver
      7. 8.3.7  Synchronous Rectifier
      8. 8.3.8  Enable/Undervoltage Lockout (EN/UVLO)
      9. 8.3.9  Power Good (PGOOD)
      10. 8.3.10 Thermal Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Active Mode
      3. 8.4.3 Sleep Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Switching Frequency (RT)
        2. 9.2.2.2  Transformer Selection
        3. 9.2.2.3  Output Capacitor Selection
        4. 9.2.2.4  Secondary Output Diode
        5. 9.2.2.5  Regulation Comparator
        6. 9.2.2.6  Input Capacitor
        7. 9.2.2.7  Type-3 Ripple Network
        8. 9.2.2.8  Minimum Secondary Output Load
        9. 9.2.2.9  Example Design Summary
        10. 9.2.2.10 Thermal Considerations
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Compact PCB Layout for EMI Reduction
      2. 11.1.2 Feedback Resistors
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7.5 Electrical Characteristics

TJ = –40°C to +150°C, VIN = 4.5 V to 120 V. Typical values are at TJ = 25°C and VIN = 24 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY
IQ(VIN) VIN quiescent current VEN = 2.5 V, PWM operation 420 880 µA
VEN = 2.5 V, PFM operation 10 25 µA
IQ(STANDBY) VIN standby current – LDO only VEN = 1.25 V 17 35 µA
ISD(VIN) VIN shutdown supply current VEN = 0 V 3 15 µA
ENABLE
VEN(R) EN voltage rising threshold EN rising, enable switching 1.45 1.5 1.55 V
VEN(F) EN voltage falling threshold EN falling, disable switching 1.35 1.4 1.44 V
VSD(R) EN standby rising threshold EN rising, enable internal LDO, no switching. 1.1 V
VSD(F) EN standby falling threshold EN falling, disable internal LDO 0.45 V
REFERENCE VOLTAGE
VFB FB voltage VFB falling 1.181 1.2 1.218 V
STARTUP
tSS Internal fixed soft-start time 1.75 3 4.75 ms
POWER STAGE
RDSON(HS) High-side MOSFET on-resistance ISW = –100 mA 1.85 Ω
RDSON(LS) Low-side MOSFET on-resistance ISW = 100 mA 0.75 Ω
tON(min) Minimum ON pulse width 50 ns
tON(1) On time1 VVIN = 6 V, RRT = 75 kΩ 5000 ns
tON(2) On time2 VVIN = 6 V, RRT = 25 kΩ 1650 ns
tON(3) On time3 VVIN = 12 V, RRT = 75 kΩ 2550 ns
tON(4) On time4 VVIN = 12 V, RRT = 25 kΩ 830 ns
tOFF(min) Minimum OFF pulse width 50 ns
BOOT CIRCUIT
VBOOT-SW(UV_R) BOOT-SW UVLO rising threshold VBOOT-SW rising 2.7 3.4 V
OVERCURRENT PROTECTION
IHS_PK(OC) High-side peak current limit LM5168 0.356 0.42 0.484 A
LM5169 0.71 0.84 0.94 A
ILS_PK(OC) Low-side peak current limit LM5168 0.356 0.42 0.484 A
LM5169 0.71 0.84 0.94 A
IDELTA(OC) Min of IHS_PK(OC) or ILS_PK(OC)  minus ILS_V(OC) LM5168 0.084 A
LM5169  0.168 A
ILS(NOC) Low-side negative current limit LM5169 1.25 1.5 1.75 A
LM5168 0.635 0.75 0.865 A
IZC Zero-cross detection current threshold 0 A
TW Hiccup time before re-start 64 ms
POWER GOOD
VPGTH Power-good threshold FB falling, PG high to low 1.055 1.08 1.1 V
FB rising, PG low to high 1.105 1.14 1.175 V
RPG Power-good on-resistance VFB = 1 V 7 Ω
THERMAL SHUTDOWN
TJ(SD) Thermal shutdown threshold (1) Temperature rising 175 °C
TJ(HYS) Thermal shutdown hysteresis (1) 10 °C
(1) Ensured by design.