SNVS528H October   2007  – January 2016 LM20143 , LM20143-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 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 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 Peak Current Mode Control
      2. 7.3.2 Precision Enable
      3. 7.3.3 Current Limit
      4. 7.3.4 Pre-Bias Start Up Capability
      5. 7.3.5 Soft-Start and Voltage Tracking
      6. 7.3.6 Power Good and Overvoltage Fault Handling
      7. 7.3.7 UVLO
      8. 7.3.8 Thermal Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Light Load Operation
      2. 7.4.2 Tracking an External Supply
      3. 7.4.3 Using Precision Enable and Power Good
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 3.3-V or 5-V Supply Rail Design
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Duty Cycle Calculation
          2. 8.2.1.2.2  Inductor Selection (L)
          3. 8.2.1.2.3  Output Capacitor Selection (COUT)
          4. 8.2.1.2.4  Input Capacitor Selection (CIN)
          5. 8.2.1.2.5  Setting the Output Voltage (RFB1, RFB2)
          6. 8.2.1.2.6  Adjusting the Operating Frequency (RT)
          7. 8.2.1.2.7  AVIN Filtering Components (CF and RF)
          8. 8.2.1.2.8  Sub-Regulator Bypass Capacitor (CVCC)
          9. 8.2.1.2.9  Setting the Start Up Time (CSS)
          10. 8.2.1.2.10 Loop Compensation (RC1, CC1)
        3. 8.2.1.3 Application Curves
      2. 8.2.2 5-V Supply Rail Design
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
      3. 8.2.3 3-V Supply Rail Design
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
  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 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 Related Links
    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

See (1)
MIN MAX UNIT
AVIN, PVIN, EN, PGOOD, SS/TRK, COMP, FB, RT Voltages from indicated pins to GND –0.3 6 V
Power Dissipation(2) 2.6 W
Junction Temperature 150 °C
Lead Temperature (Soldering, 10 sec) 260 °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) The maximum allowable power dissipation is a function of the maximum junction temperature, TJ_MAX, the junctions-to-ambient thermal resistance, θJA, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using: PD_MAX = (TJ_MAX – TA) / θJA. The maximum power dissipations of 2.6 W is determined using TA = 25°C, θJA = 38°C/W, and TJ_MAX = 125°C.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±1000
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

MIN MAX UNIT
PVIN, AVIN to GND 2.95 5.5 V
Junction Temperature −40 125 °C

6.4 Thermal Information

THERMAL METRIC(1) LM20143 UNIT
PWP (HTSSOP)
16 PINS
RθJA Junction-to-ambient thermal resistance (2) 39.3 °C/W
RθJC(top) Junction-to-case (top) thermal resistance (3) 20.3 °C/W
RθJB Junction-to-board thermal resistance 9.9 °C/W
ψJT Junction-to-top characterization parameter 0.6 °C/W
ψJB Junction-to-board characterization parameter 9.9 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 12.1 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.
(2) On JEDEC 4-Layer test board (JESD 51-7) with eight (8) thermal vias.
(3) θJC refers to center of the Exposed Pad on the bottom of the package as the case.

6.5 Electrical Characteristics

Unless otherwise stated, the following conditions apply: AVIN = PVIN = VIN = 5 V. All Typical limits are for TJ = 25°C only, all Minimum and Maximum limits apply over the junction temperature (TJ) range of –40°C to 125°C(1). Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VFB Feedback pin voltage VIN = 2.95 V to 5.5 V 0.788 0.8 0.812 V
ΔVOUT/ΔIOUT Load Regulation IOUT = 100 mA to 3 A 0.08 %/A
ICL Switch Current Limit Threshold VIN = 3.3 V 4.3 4.8 5.3 A
RDS_ON High-Side Switch On Resistance ISW = 3.5 A 36 55 mΩ
RDS_ON Low-Side Switch On Resistance ISW = 3.5 A 32 52 mΩ
IQ Operating Quiescent Current Non-switching, VFB = VCOMP 3.5 6 mA
ISD Shutdown Quiescent current VEN = 0 V 90 180 µA
VUVLO VIN Under Voltage Lockout Rising VIN 2.45 2.7 2.95 V
VUVLO_HYS VIN Under Voltage Lockout Hysteresis Falling VIN 45 100 mV
VVCC VCC Voltage IVCC = 0 µA 2.45 2.7 2.95 V
ISS Soft-Start Pin Source Current VSS/TRK = 0 V 2 4.5 7 µA
VTRACK SS/TRK Accuracy, VSS - VFB VSS/TRK = 0.4 V –10 3 15 mV
OSCILLATOR
FOSCH Oscillator Frequency RT = 49.9 kΩ 1350 1500 1650 kHz
FOSCL Oscillator Frequency RT = 249 kΩ 450 510 570 kHz
DCMAX Maximum Duty Cycle ILOAD = 0 A 85%
TON_TIME Minimum On Time 100 ns
TCL_BLANK Current Sense Blanking Time After Rising VSW 80 ns
ERROR AMPLIFIER AND MODULATOR
IFB Feedback pin bias current VFB = 0.8 V 1 100 nA
ICOMP_SRC COMP Output Source Current VFB = VCOMP = 0.6 V 80 100 µA
ICOMP_SNK COMP Output Sink Current VFB = 1.0 V, VCOMP = 0.6 V 80 100 µA
Gm Error Amplifier Transconductance ICOMP = ± 50 µA 450 510 600 µmho
AVOL Error Amplifier Voltage Gain 2000 V/V
POWER GOOD
VOVP Over Voltage Protection Rising Threshold With respect to VFB 105% 108% 111%
VOVP_HYS Over Voltage Protection Hysteresis With respect to VFB 2% 3%
VPGTH PGOOD Rising Threshold With respect to VFB 92% 94% 96%
VPGHYS PGOOD Falling Hysteresis With respect to VFB 2% 3%
TPGOOD PGOOD deglitch time 16 µs
IOL PGOOD Low Sink Current VPGOOD = 0.4 V 0.6 1 mA
IOH PGOOD High Leakage Current VPGOOD = 5 V 5 100 nA
ENABLE
VIH_EN EN Pin turn-on Threshold VEN Rising 1.08 1.18 1.28 V
VEN_HYS EN Pin Hysteresis 66 mV
THERMAL SHUTDOWN
TSD Thermal Shutdown 160 °C
TSD_HYS Thermal Shutdown Hysteresis 10 °C
(1) Minimum and Maximum limits are specified by test, design, or statistical correlation.

6.6 Typical Characteristics

Unless otherwise specified: CIN = COUT = 100 µF, L = 1.0 µH, VIN = 5 V, VOUT = 1.2 V, RLOAD = 1.2 Ω, fSW = 1 MHz, TA = 25°C for efficiency curves, loop gain plots and waveforms, and TJ = 25°C for all others.
LM20143 LM20143-Q1 30030531.png
VIN = 5 V fSW = 1.5 MHz
Figure 1. Efficiency vs Load Current
LM20143 LM20143-Q1 30030547.png
VIN = 5 V fSW = 1.0 MHz
Figure 3. Efficiency vs Load Current
LM20143 LM20143-Q1 30030549.png
VIN = 5.0 V fSW 500 kHz
Figure 5. Efficiency vs Load Current
LM20143 LM20143-Q1 30030557.png Figure 7. High-Side FET Resistance vs Temperature
LM20143 LM20143-Q1 30030536.png Figure 9. Error Amplifier Gain vs Frequency
LM20143 LM20143-Q1 30030538.png Figure 11. Load Regulation
LM20143 LM20143-Q1 30030539.png Figure 13. Switching Frequency vs Temperature
LM20143 LM20143-Q1 30030540.png Figure 15. Quiescent Current vs VIN (Not Switching)
LM20143 LM20143-Q1 30030528.png Figure 17. Enable Threshold vs Temperature
LM20143 LM20143-Q1 30030542.png Figure 19. Peak Current Limit vs Temperature
LM20143 LM20143-Q1 30030555.png Figure 21. Peak Current Limit vs VIN
LM20143 LM20143-Q1 30030543.png Figure 23. Line Transient Response
LM20143 LM20143-Q1 30030533.png Figure 25. Start Up (Tracking)
LM20143 LM20143-Q1 30030532.png Figure 27. Power Down
LM20143 LM20143-Q1 30030530.png
VIN = 3.3 V fSW = 1.5 MHz
Figure 2. Efficiency vs Load Current
LM20143 LM20143-Q1 30030546.png
VIN = 3.3 V fSW = 1.0 MHz
Figure 4. Efficiency vs Load Current
LM20143 LM20143-Q1 30030548.png
VIN = 3.3 V fSW = 500 kHz
Figure 6. Efficiency vs Load Current
LM20143 LM20143-Q1 30030558.png Figure 8. Low-Side FET Resistance vs Temperature
LM20143 LM20143-Q1 30030537.png Figure 10. Line Regulation
LM20143 LM20143-Q1 30030551.png Figure 12. Feedback Pin Voltage vs Temperature
LM20143 LM20143-Q1 30030550.png Figure 14. Switching Frequency vs RT
LM20143 LM20143-Q1 30030541.png Figure 16. Shutdown Current vs Temperature
LM20143 LM20143-Q1 30030545.png Figure 18. UVLO Threshold vs Temperature
LM20143 LM20143-Q1 30030554.png Figure 20. Peak Current Limit vs VOUT
LM20143 LM20143-Q1 30030534.png Figure 22. Load Transient Response
LM20143 LM20143-Q1 30030544.png Figure 24. Start Up (Soft-Start)
LM20143 LM20143-Q1 30030556.png Figure 26. Short Circuit Input Current vs VIN