SNVS666H June   2010  – October 2015 LMZ14203EXT

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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 COT Control Circuit Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Output Overvoltage Comparator
      2. 7.3.2 Current Limit
      3. 7.3.3 Thermal Protection
      4. 7.3.4 Zero Coil Current Detection
      5. 7.3.5 Prebiased Start-Up
    4. 7.4 Device Functional Modes
      1. 7.4.1 Discontinuous Conduction and Continuous Conduction Modes
  8. 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 Design Steps for the LMZ14203EXT Application
          1. 8.2.2.1.1 Enable Divider, RENT and RENB Selection
          2. 8.2.2.1.2 Output Voltage Selection
          3. 8.2.2.1.3 Soft-Start Capacitor Selection
          4. 8.2.2.1.4 CO Selection
          5. 8.2.2.1.5 CIN Selection
          6. 8.2.2.1.6 RON Resistor Selection
            1. 8.2.2.1.6.1 Discontinuous Conduction and Continuous Conduction Mode Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 Power Dissipation and Board Thermal Requirements
    4. 10.4 Power Module SMT Guidelines
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    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

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)(2).
MIN MAX UNIT
VIN, RON to GND –0.3 43.5 V
EN, FB, SS to GND –0.3 7 V
Junction temperature 150 °C
Peak reflow case temperature (30 sec) 245 °C
Storage temperature –65 150 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability
(2) For soldering specifications, refer to Absolute Maximum Ratings for Soldering SNOA549.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
VIN 6 42 V
EN 0 6.5 V
Operation Junction Temperature –55 125 °C

6.4 Thermal Information

THERMAL METRIC(1) LMZ14203EXT UNIT
NDW (TO-PMOD)
7 PINS
RθJA Junction-to-ambient thermal resistance(2) 4-layer JEDEC Printed-Circuit-Board, 100 vias, No air flow 19.3 °C/W
2-layer JEDEC Printed-Circuit-Board, No air flow 21.5 °C/W
RθJC(top) Junction-to-case (top) thermal resistance No air flow 1.9 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.
(2) RθJA measured on a 1.705-in × 3.0-in 4-layer board, with 1-oz copper, thirty-five thermal vias, no air flow, and 1-W power dissipation. Refer to Figure 36.

6.5 Electrical Characteristics

Limits are for TJ = 25°C unless otherwise specified. Minimum and Maximum limits are ensured 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 = 24 V, VOUT = 3.3 V.
PARAMETER CONDITIONS MIN(1) TYP(2) MAX(1) UNIT
SYSTEM PARAMETERS(3)
ENABLE CONTROL
VEN EN threshold trip point VEN rising 1.18 V
over the junction temperature (TJ) range of –55°C to 125°C 1.1 1.26
VEN-HYS EN threshold hysteresis VEN falling 90 mV
SOFT-START
ISS SS source current VSS = 0 V 8 µA
over the junction temperature (TJ) range of –55°C to 125°C 4.9 11
ISS-DIS SS discharge current –200 µA
CURRENT LIMIT
ICL Current limit threshold DC average
VIN = 12 V to 24 V		 4.2 A
over the junction temperature (TJ) range of –55°C to 125°C 3.15 5.3
REGULATION AND OVERVOLTAGE COMPARATOR
VFB In-regulation feedback voltage VSS >+ 0.8 V
TJ = –55°C to 125°C
IO = 3 A		 0.804 V
over the junction temperature (TJ) range of –55°C to 125°C 0.784 0.825
VSS >+ 0.8 V
TJ = 25°C
IO = 10 mA		 0.786 0.802 0.818 V
VFB-OV Feedback overvoltage protection threshold 0.92 V
IFB Feedback input bias current 5 nA
IQ Non-switching input current VFB = 0.86 V 1 mA
ISD Shutdown quiescent current VEN = 0 V 25 μA
THERMAL CHARACTERISTICS
TSD Thermal shutdown Rising 165 °C
TSD-HYST Thermal shutdown hysteresis Falling 15 °C
PERFORMANCE PARAMETERS
ΔVO Output voltage ripple 8 mVPP
ΔVO/ΔVIN Line regulation VIN = 12 V to 42 V, IO = 3 A 0.01%
ΔVO/IOUT Load regulation VIN = 24 V 1.5 mV/A
η Efficiency VIN = 24 V, VO = 3.3 V, IO = 1 A 92%
VIN = 24 V, VO = 3.3 V, IO = 3 A 85%
(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 Average Outgoing Quality Level (AOQL).
(2) Typical numbers are at 25°C and represent the most likely parametric normal.
(3) EN 55022:2006, +A1:2007, FCC Part 15 Subpart B: 2007. See AN-2024 LMZ1420x / LMZ1200x Evaluation Board, SNVA422 and layout for information on device under test.

6.6 Switching Characteristics

over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
ON/OFF TIMER
tON-MIN ON timer minimum pulse width 150 ns
tOFF OFF timer pulse width 260 ns

6.7 Typical Characteristics

Unless otherwise specified, the following conditions apply: VIN = 24 V; CIN = 10-µF X7R Ceramic; CO = 100-µF X7R Ceramic; TA = 25°C for efficiency curves and waveforms.
LMZ14203EXT 30117831.gif
Figure 1. Efficiency 6-V Input at 25°C
LMZ14203EXT 30117803.gif
Figure 3. Efficiency 12-V Input at 25°C
LMZ14203EXT 30117826.gif
Figure 5. Efficiency 24-V Input at 25°C
LMZ14203EXT 30117829.gif
Figure 7. Efficiency 36-V Input at 25°C
LMZ14203EXT 30117833.gif
Figure 9. Efficiency 6-V Input at 85°C
LMZ14203EXT 30117840.gif
Figure 11. Efficiency 8-V Input at 85°C
LMZ14203EXT 30117842.gif
Figure 13. Efficiency 12-V Input at 85°C
LMZ14203EXT 30117844.gif
Figure 15. Efficiency 24-V Input at 85°C
LMZ14203EXT 30117846.gif
Figure 17. Efficiency 36-V Input at 85°C
LMZ14203EXT 30117861.gif
Figure 19. Line and Load Regulation at 25°C
LMZ14203EXT 30117863.gif
Figure 21. Line and Load Regulation at –55°C
LMZ14203EXT 30117806.gif
Figure 23. Transient Response
24 VIN 3.3 VO 0.6-A to 3-A Step
LMZ14203EXT 30117858.gif
Figure 25. Current Limit 3.3 VOUT at 25°C
LMZ14203EXT 30117860.gif
Figure 27. Current Limit 3.3 VOUT at –55°C
LMZ14203EXT 30117832.gif
Figure 2. Dissipation 6-V Input at 25°C
LMZ14203EXT 30117804.gif
Figure 4. Dissipation 12-V Input at 25°C
LMZ14203EXT 30117827.gif
Figure 6. Dissipation 24-V Input ay 25°C
LMZ14203EXT 30117830.gif
Figure 8. Dissipation 36-V Input at 25°C
LMZ14203EXT 30117834.gif
Figure 10. Dissipation 6-V Input at 85°C
LMZ14203EXT 30117841.gif
Figure 12. Dissipation 8-V Input at 85°C
LMZ14203EXT 30117843.gif
Figure 14. Dissipation 12-V Input at 85°C
LMZ14203EXT 30117845.gif
Figure 16. Dissipation 24-V Input at 85°C
LMZ14203EXT 30117847.gif
Figure 18. Dissipation 36-V Input at 85°C
LMZ14203EXT 30117862.gif
Figure 20. Line and Load Regulation at 85°C
LMZ14203EXT 30117805.gif
Figure 22. Output Ripple
24 VIN 3.3 VO 3 A, BW = 200 MHz
LMZ14203EXT 30117851.gif
Figure 24. Thermal Derating VOUT = 3.3 V
LMZ14203EXT 30117859.gif
Figure 26. Current Limit 3.3 VOUT at 85°C