SNVS588M September   2008  – November 2014 LM22672 , LM22672-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: LM22672
    3. 6.3 Handling Ratings: LM22672-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 Switching Frequency Adjustment and Synchronization
      4. 7.3.4 Self-Synchronization
      5. 7.3.5 Boot-Strap Supply
      6. 7.3.6 Internal Loop Compensation
    4. 7.4 Device Functional Mode
      1. 7.4.1 Current Limit
      2. 7.4.2 Thermal Protection
      3. 7.4.3 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 Application
      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. 8.2.1.2.1.2 Input Capacitor
            3. 8.2.1.2.1.3 Output Capacitor
            4. 8.2.1.2.1.4 Boot-strap Capacitor
        3. 8.2.1.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6 Specifications

6.1 Absolute Maximum Ratings(1)(2)

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
VIN to GND 43 V
EN Pin Voltage –0.5 6 V
SS, RT/SYNC Pin Voltage –0.5 7 V
SW to GND(3) –5 VIN V
BOOT Pin Voltage VSW + 7 V
FB Pin Voltage –0.5 7 V
Power Dissipation Internally Limited
Junction Temperature 150 °C
For soldering specifications, refer to Application Report Absolute Maximum Ratings for Soldering (SNOA549).

6.2 Handling Ratings: LM22672

MIN MAX UNIT
Tstg Storage temperature range –65 150 °C
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) –2 2 kV
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

6.3 Handling Ratings: LM22672-Q1

MIN MAX UNIT
Tstg Storage temperature range –65 150 °C
V(ESD) Electrostatic discharge Human body model (HBM), per AEC Q100-002(1) –2 2 kV
(1) AEC Q100-002 indicates HBM stressing is done in accordance with the ANSI/ESDA/JEDEC JS-001 specification.

6.4 Recommended Operating Conditions

MIN MAX UNIT
VIN Supply Voltage 4.5 42 V
Junction Temperature Range –40 125 °C

6.5 Thermal Information

THERMAL METRIC(1) LM22672, LM22672-Q1 UNIT
HSOP
8 PINS
RθJA Junction-to-ambient thermal resistance MR Package, Junction to ambient thermal resistance(2) 60 °C/W
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report (SPRA953).
(2) The value of RθJA for the SO PowerPAD exposed pad (MR) package of 60°C/W is valid if package is mounted to 1 square inch of copper. The RθJA value can range from 42 to 115°C/W depending on the amount of PCB copper dedicated to heat transfer.

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.
PARAMETER TEST CONDITIONS MIN(5) TYP(4) MAX(5) UNIT
LM22672-5.0
VFB Feedback Voltage VIN = 8 V to 42 V 4.925 5.0 5.075 V
VIN = 8 V to 42 V, –40°C ≤ TJ ≤ 125°C 4.9 5.1
LM22672-ADJ
VFB Feedback Voltage VIN = 4.7 V to 42 V 1.266 1.285 1.304 V
VIN = 4.7 V to 42 V, –40°C ≤ TJ ≤ 125°C 1.259 1.311
ALL OUTPUT VOLTAGE VERSIONS
IQ Quiescent Current VFB = 5 V 3.4 mA
VFB = 5 V, –40°C ≤ TJ ≤ 125°C 6
ISTDBY Standby Quiescent Current EN Pin = 0 V 25 40 µA
ICL Current Limit 1.3 1.5 1.7 A
–40°C ≤ TJ ≤ 125°C 1.2 1.8
IL Output Leakage Current VIN = 42 V, EN Pin = 0 V, VSW = 0 V 0.2 2 µA
VSW = –1 V 0.1 3 µA
RDS(ON) Switch On-Resistance 0.2 0.24 Ω
–40°C ≤ TJ ≤ 125°C 0.32
Fsw Oscillator Frequency 500 kHz
–40°C ≤ TJ ≤ 125°C 400 600
TOFF Minimum Off-time 200 ns
–40°C ≤ TJ ≤ 125°C 100 300
TON Minimum On-time 100 ns
IBIAS Feedback Bias Current VFB = 1.3 V (ADJ Version Only) 230 nA
VEN Enable Threshold Voltage Falling 1.6 V
Falling, –40°C ≤ TJ ≤ 125°C 1.3 1.9
VENHYST Enable Voltage Hysteresis 0.6 V
IEN Enable Input Current EN Input = 0 V 6 µA
FSYNC Maximum Synchronization Frequency VSYNC = 3.5 V, 50% duty-cycle 1 MHz
VSYNC Synchronization Threshold Voltage 1.75 V
ISS Soft-Start Current 50 µA
–40°C ≤ TJ ≤ 125°C 30 70
TSD Thermal Shutdown Threshold 150 °C
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur, including inoperability and degradation of device reliability and/or performance. Functional operation of the device and/or non-degradation at the Absolute Maximum Ratings or other conditions beyond those indicated in the Recommended Operating Conditions is not implied. Recommended Operating Conditions indicate conditions at which the device is functional and should not be operated beyond such conditions. For ensured specifications and conditions, see the Electrical Characteristics table.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/Distributors for availability and specifications.
(3) The absolute maximum specification of the ‘SW to GND’ applies to dc voltage. An extended negative voltage limit of –10 V applies to a pulse of up to 50 ns.
(4) Typical values represent most likely parametric norms at the conditions specified and are not ensured.
(5) 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 Average Outgoing Quality Level (AOQL).

6.7 Typical Characteristics

Vin = 12 V, TJ = 25°C (unless otherwise specified)
30076727.pngFigure 1. Efficiency vs IOUT and VIN, VOUT = 3.3 V
30076703.pngFigure 3. Current Limit vs Temperature
30076705.pngFigure 5. Feedback Bias Current vs Temperature
30076706.pngFigure 7. Standby Quiescent Current vs Input Voltage
30076709.pngFigure 9. Normalized Feedback Voltage vs Input Voltage
30076742.pngFigure 11. Soft-Start Current vs Temperature
30076704.pngFigure 2. Normalized Switching Frequency vs Temperature
30076708.pngFigure 4. Normalized RDS(ON) vs Temperature
30076710.pngFigure 6. Normalized Enable Threshold Voltage vs Temperature
30076707.pngFigure 8. Normalized Feedback Voltage vs Temperature
30076713.pngFigure 10. Switching Frequency vs RT/SYNC Resistor