SNVS585M September   2008  – October 2020 LM22678 , LM22678-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 Handling Ratings: LM22678
    3. 6.3 Handling Ratings: LM22678-Q1
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Thermal Information
    6. 6.6 Electrical Characteristics
    7. 6.7 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 Precision Enable and UVLO
      2. 7.3.2 Soft Start
      3. 7.3.3 Bootstrap Supply
      4. 7.3.4 Internal Loop Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
      3. 7.4.3 Current Limit
      4. 7.4.4 Thermal Protection
      5. 7.4.5 Duty-Cycle Limits
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Output Voltage Divider Selection
      2. 8.1.2 Power Diode
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Buck Regulator Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 External Components
            1. 8.2.1.2.1.1 Inductor
          2. 8.2.1.2.2 Input Capacitor
          3. 8.2.1.2.3 Output Capacitor
          4. 8.2.1.2.4 Bootstrap Capacitor
        3. 8.2.1.3 Application Curves
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
    3. 9.3 Thermal Considerations
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Support Resources
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary

Package Options

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

6.6 Electrical Characteristics

Typical values represent the most likely parametric norm at TA = TJ = 25°C, and are provided for reference purposes only. Unless otherwise specified: VIN = 12 V.
PARAMETERTEST CONDITIONSMIN(1)TYP(2)MAX(1)UNIT
LM22678-5.0
VFBFeedback VoltageVIN = 8 V to 42 V4.9255.05.075V
VIN = 8 V to 42 V, –40°C ≤ TJ ≤ 125°C4.95.1
LM22678-ADJ
VFBFeedback VoltageVIN = 4.7 V to 42 V1.2661.2851.304 V
VIN = 4.7 V to 42 V, –40°C ≤ TJ ≤ 125°C1.2591.311
ALL OUTPUT VOLTAGE VERSIONS
IQQuiescent CurrentVFB = 5 V3.4mA
VFB = 5 V, –40°C ≤ TJ ≤ 125°C6
ISTDBYStandby Quiescent CurrentEN Pin = 0 V2540µA
ICLCurrent Limit6.07.18.4A
–40°C ≤ TJ ≤ 125°C5.758.75
ILOutput Leakage CurrentVIN = 42 V, EN Pin = 0 V, VSW = 0 V0.22µA
VSW = –1 V0.13µA
RDS(ON)Switch On-Resistance0.10.14Ω
–40°C ≤ TJ ≤ 125°C0.2
fOOscillator Frequency500kHz
–40°C ≤ TJ ≤ 125°C400600
TOFFMINMinimum Off-time200ns
–40°C ≤ TJ ≤ 125°C100300
TONMINMinimum On-time100ns
IBIASFeedback Bias CurrentVFB = 1.3 V (ADJ Version Only)230nA
VENEnable Threshold VoltageFalling1.6V
Falling, –40°C ≤ TJ ≤ 125°C1.31.9
VENHYSTEnable Threshold Hysteresis0.6V
IENEnable Input CurrentEN Input = 0 V6µA
TSDThermal Shutdown Threshold150°C
(1) MIN and MAX limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlation using Statistical Quality Control (SQC) methods. Limits are used to calculate TI's Average Outgoing Quality Level (AOQL).
(2) Typical values represent most likely parametric norms at the conditions specified and are not ensured.