SLVSFL2B May   2021  – December 2022 TPS7H4002-SP

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  VIN and Power VIN Pins (VIN and PVIN)
      2. 7.3.2  Voltage Reference
      3. 7.3.3  Adjusting the Output Voltage
      4. 7.3.4  Safe Start-Up Into Prebiased Outputs
      5. 7.3.5  Error Amplifier
      6. 7.3.6  Slope Compensation
      7. 7.3.7  Enable and Adjust UVLO
      8. 7.3.8  Adjustable Switching Frequency and Synchronization (SYNC)
      9. 7.3.9  Slow Start (SS/TR)
      10. 7.3.10 Power Good (PWRGD)
      11. 7.3.11 Sequencing (SS/TR)
      12. 7.3.12 Output Overvoltage Protection (OVP)
      13. 7.3.13 Overcurrent Protection
        1. 7.3.13.1 High-Side MOSFET Overcurrent Protection
        2. 7.3.13.2 Low-Side MOSFET Overcurrent Protection
      14. 7.3.14 Thermal Shutdown
      15. 7.3.15 Turn-On Behavior
      16. 7.3.16 Small Signal Model for Frequency Compensation
    4. 7.4 Device Functional Modes
      1. 7.4.1 Fixed-Frequency PWM Control
      2. 7.4.2 Continuous Current Mode (CCM) Operation
  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 Operating Frequency
        2. 8.2.2.2 Output Inductor Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Output Schottky Diode
        5. 8.2.2.5 Slow Start Capacitor Selection
        6. 8.2.2.6 Undervoltage Lockout (UVLO) Set Point
        7. 8.2.2.7 Output Voltage Feedback Resistor Selection
        8. 8.2.2.8 Compensation Component Selection
      3. 8.2.3 Parallel Operation
      4. 8.2.4 Application Curve
  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 Documentation Support
      1. 11.1.1 Related Documentation
    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

8.2.2.4 Output Schottky Diode

Figure 8-1 shows a Schottky diode between the phase node pin (PH) and GND of the TPS7H4002-SEP. This external diode is in parallel with the internal low-side power FET of the device and typically has superior reverse recovery characteristics when compared to the body diode of the internal low-side FET. This improved reverse recovery provides two key benefits. The first benefit is an better overall efficiency for the converter due to lower losses associated with the diode reverse recovery. The second key advantage is that the parasitic-induced noise associated with the reverse recovery current pulse (as detailed in Figure 5 of Power Loss Calculation With Common Source Inductance Consideration for Synchronous Buck Converters) is drastically reduced. In the absence of the Schottky diode, this noise can manifest itself on the power ground plane internal to the TPS7H4002-SEP. If significant enough, the noise can reduce the dynamic range of the error amplifier and result in higher output voltage ripple. For this reason, it is highly recommended to use the external Schottky diode in the converter design. At the least, a PCB footprint for the diode should be included in the PCB design phase in case it is needed to achieve the system requirements.