SLVSEZ9 January   2019 TPS54540B

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Efficiency vs Load Current
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Timing Requirements
    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  Fixed Frequency PWM Control
      2. 7.3.2  Slope Compensation Output Current
      3. 7.3.3  Pulse Skip Eco-mode
      4. 7.3.4  Low Dropout Operation and Bootstrap Voltage (BOOT)
      5. 7.3.5  Error Amplifier
      6. 7.3.6  Adjusting the Output Voltage
      7. 7.3.7  Enable and Adjusting Undervoltage Lockout
      8. 7.3.8  Internal Soft Start
      9. 7.3.9  Constant Switching Frequency and Timing Resistor (RT/CLK) pin)
      10. 7.3.10 Accurate Current-Limit Operation and Maximum Switching Frequency
      11. 7.3.11 Synchronization to RT/CLK pin
      12. 7.3.12 Overvoltage Protection
      13. 7.3.13 Thermal Shutdown
      14. 7.3.14 Small Signal Model for Loop Response
      15. 7.3.15 Simple Small Signal Model for Peak-Current-Mode Control
      16. 7.3.16 Small Signal Model for Frequency Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation with VIN < 4.5 V (Minimum VIN)
      2. 7.4.2 Operation with EN Control
  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  Custom Design with WEBENCH® Tools
        2. 8.2.2.2  Selecting the Switching Frequency
        3. 8.2.2.3  Output Inductor Selection (LO)
        4. 8.2.2.4  Output Capacitor
        5. 8.2.2.5  Catch Diode
        6. 8.2.2.6  Input Capacitor
        7. 8.2.2.7  Bootstrap Capacitor Selection
        8. 8.2.2.8  Undervoltage Lockout Set Point
        9. 8.2.2.9  Output Voltage and Feedback Resistors Selection
        10. 8.2.2.10 Minimum VIN
        11. 8.2.2.11 Compensation
        12. 8.2.2.12 Discontinuous Conduction Mode and Eco-mode Boundary
        13. 8.2.2.13 Power Dissipation Estimate
        14. 8.2.2.14 Safe Operating Area
      3. 8.2.3 Application Curves
    3. 8.3 Other System Examples
      1. 8.3.1 Inverting Power
      2. 8.3.2 Split-Rail Power Supply
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 Estimated Circuit Area
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Custom Design with WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6.5 Electrical Characteristics

TJ = –40°C to +150°C, VIN = 4.5 V to 42 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
SUPPLY VOLTAGE (VIN PIN)
Operating input voltage 4.5 42 V
Internal undervoltage lockout threshold Rising 4.1 4.3 4.48 V
Internal undervoltage lockout threshold hysteresis 325 mV
Shutdown supply current EN = 0 V, 25°C, 4.5 V ≤ VIN ≤ 42 V 2.25 4.5 μA
Operating: nonswitching supply current FB = 0.9 V, TA = 25°C 146 175
ENABLE AND UVLO (EN PIN)
Enable threshold voltage No voltage hysteresis, rising and falling 1.1 1.2 1.3 V
Input current Enable threshold +50 mV –4.6 μA
Enable threshold –50 mV –0.58 –1.2 -1.8
Hysteresis current –2.2 –3.4 -4.5 μA
VOLTAGE REFERENCE
Voltage reference 0.792 0.8 0.808 V
HIGH-SIDE MOSFET
On-resistance VIN = 12 V, BOOT-SW = 6 V 92 190 mΩ
ERROR AMPLIFIER
Input current 50 nA
Error amplifier dc gain VFB = 0.8 V 10,000 V/V
Min unity gain bandwidth 2500 kHz
Error amplifier source/sink V(COMP) = 1 V, 100 mV overdrive ±30 μA
COMP to SW current transconductance 17 A/V
CURRENT LIMIT
Current limit test All VIN and temperatures, open loop(1) 6.3 7.9 9.5 A
All temperatures, VIN = 12 V, open loop(1) 6.3 7.9 9.5
VIN = 12 V, TA = 25°C, Open Loop(1) 7 7.9 8.8
THERMAL SHUTDOWN
Thermal shutdown 176 °C
Thermal shutdown hysteresis 12 °C
TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK PIN)
Switching frequency range using RT mode 100 2500 kHz
fSW Switching frequency RT = 200 kΩ 450 500 550 kHz
Switching frequency range using CLK mode 160 2300 kHz
RT/CLK high threshold 1.55 2 V
RT/CLK low threshold 0.5 1.2 V
(1) Open loop current limit measured directly at the SW pin and is independent of the inductor value and slope compensation.