SNVSBC0C September   2020  – December 2021 TPS542A50

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  Enable and Adjustable Undervoltage Lockout
      2. 7.3.2  Input and VREG Undervoltage Lockout Protection
      3. 7.3.3  Voltage Reference and Setting the Output Voltage
      4. 7.3.4  Remote Sense Function
      5. 7.3.5  Switching Frequency
      6. 7.3.6  Voltage Control Mode Internal Compensation
      7. 7.3.7  Soft Start and Prebiased Output Start-up
      8. 7.3.8  Power Good
      9. 7.3.9  Overvoltage and Undervoltage Protection
      10. 7.3.10 Overcurrent Protection
      11. 7.3.11 High-Side FET Throttling
      12. 7.3.12 Overtemperature Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Pulse-Frequency Modulation Eco-mode Light Load Operation
      2. 7.4.2 Forced Continuous-Conduction Mode
      3. 7.4.3 Soft Start
    5. 7.5 Programming
      1. 7.5.1 I2C Address Selection
      2. 7.5.2 Powering Device Into Programming Mode
      3. 7.5.3 Device Configuration
      4. 7.5.4 Output Voltage Adjustment
    6. 7.6 Pin-Strap Programming
    7. 7.7 Register Maps
      1. 7.7.1 ID Register (Offset = 0x0) [reset = 0x21]
      2. 7.7.2 STATUS Register (Offset = 0x1) [reset = 0x0]
      3. 7.7.3 VOUT_ADJ1 Register (Offset = 0x2) [reset = 0x0]
      4. 7.7.4 VOUT_ADJ2 Register (Offset = 0x3) [reset = 0x0]
      5. 7.7.5 CONFIG1 Register (Offset = 0x4) [reset = 0x0B]
      6. 7.7.6 CONFIG2 Register (Offset = 0x5) [reset = 0x2D]
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Full Analog Configuration
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2  Output Voltage Calculation
          3. 8.2.1.2.3  Switching Frequency Selection
          4. 8.2.1.2.4  Inductor Selection
          5. 8.2.1.2.5  Input Capacitor Selection
          6. 8.2.1.2.6  Bootstrap Capacitor Selection
          7. 8.2.1.2.7  R-C Snubber and VIN Pin High-Frequency Bypass
          8. 8.2.1.2.8  Output Capacitor Selection
          9. 8.2.1.2.9  Response to a Load Transient
          10. 8.2.1.2.10 Pin-Strap Setting
        3. 8.2.1.3 Application Curves
        4. 8.2.1.4 Typical Application Circuits
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Fusion Digital Power™ Designer Tool
        2. 11.1.1.2 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support 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

7.3.5 Switching Frequency

The internal oscillator of the device can be set to one of seven switching frequencies by a resistor to ground on the FSEL pin or through I2C programming. The FSEL pin can be shorted to ground to reduce BOM component count. When shorted to ground, the default converter switching frequency is used. If the user programs the switching frequency using the I2C interface, TI recommends shorting the FSEL pin to ground to reduce component count. The following frequencies can be programmed on the FSEL pin.

Table 7-1 Frequency Resistor Selection
RFSEL (kΩ)fSW (kHz)
Short1000
7.5400
18.2600
26.1800
35.71000
47.51200
61.92000
78.72200

The oscillator can also be synchronized to an external clock on the SYNC pin. The external clock frequency must be within -10% and +15% of the programmed frequency of the converter. The SYNC pin has an internal pulldown so it can be left floating externally.

When the converter operates at 2 MHz or 2.2 MHz, it is recommended to set the OCP at 13 A or lower and without a snubber circuit. For operation with OCP at 16.5 A, a snubber circuit is required. The snubber circuit components can start with a 470-pF cap and 2-Ω resistor to help reduce voltage ringing levels. It is recommended for the ringing levels to be 2-V below the Absolute Maximum Ratings between SW and GND at room temperature. The component values will need to be tuned to achieve optimal results.