SLTS278J November   2010  – March 2020 PTH08T250W

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1. Table 1. Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Electrical Characteristics
    3. 7.3 Typical Characteristics (VI = 12 V)
    4. 7.4 Typical Characteristics (VI = 5 V)
  8. 8 Detailed Description
    1. 8.1 Overview: TurboTrans™ Technology
    2. 8.2 Feature Description
      1. 8.2.1 Soft-Start Power-Up
      2. 8.2.2 Differential Output Voltage Remote Sense
      3. 8.2.3 Overcurrent Protection
      4. 8.2.4 Overtemperature Protection (OTP)
  9. 9 Application and Implementation
    1. 9.1 Typical Application
      1. 9.1.1 Detailed Design Procedure
        1. 9.1.1.1  Adjusting the Output Voltage
        2. 9.1.1.2  Capacitor Recommendations for the PTH08T250W Power Module
          1. 9.1.1.2.1 Capacitor Technologies
          2. 9.1.1.2.2 Input Capacitor (Required)
          3. 9.1.1.2.3 Input Capacitor Information
          4. 9.1.1.2.4 Output Capacitor (Required)
          5. 9.1.1.2.5 Output Capacitor Information
          6. 9.1.1.2.6 TurboTrans Output Capacitance
          7. 9.1.1.2.7 Non-TurboTrans Output Capacitance
          8. 9.1.1.2.8 Designing for Fast Load Transients
          9. 9.1.1.2.9 Capacitor Table
        3. 9.1.1.3  TurboTrans™ Technology
        4. 9.1.1.4  TurboTrans™ Selection
          1. 9.1.1.4.1 PTH08T250W Type B Capacitors
            1. 9.1.1.4.1.1 RTT Resistor Selection
          2. 9.1.1.4.2 PTH08T250W Type C Capacitors
            1. 9.1.1.4.2.1 RTT Resistor Selection
        5. 9.1.1.5  Undervoltage Lockout (UVLO)
          1. 9.1.1.5.1 UVLO Adjustment
        6. 9.1.1.6  On/Off Inhibit
        7. 9.1.1.7  Current Sharing
          1. 9.1.1.7.1 Current Sharing and TurboTrans
            1. 9.1.1.7.1.1 Current Sharing Thermal Derating Curves
            2. 9.1.1.7.1.2 Current Sharing Layout
        8. 9.1.1.8  Prebias Startup Capability
        9. 9.1.1.9  SmartSync Technology
        10. 9.1.1.10 Auto-Track™ Function
          1. 9.1.1.10.1 How Auto-Track™ Works
          2. 9.1.1.10.2 Typical Auto-Track Application
          3. 9.1.1.10.3 Notes on Use of Auto-Track™
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape, Reel, and Tray Drawings

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • BCU|22
  • ECT|22
  • ECU|22
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.2.1 Soft-Start Power-Up

The Auto-Track feature allows the power-up of multiple PTH/PTV modules to be directly controlled from the Track pin. However in a stand-alone configuration, or when the Auto-Track feature is not being used, the Track pin should be directly connected to the input voltage, VI (see Figure 11).

PTH08T250W v07102_lts278.gifFigure 11. Defeating the Auto-Track Function
PTH08T250W softstartwf_lts278.gifFigure 12. Power-Up Waveform

When the Track pin is connected to the input voltage the Auto-Track function is permanently disengaged. This allows the module to power up entirely under the control of its internal soft-start circuitry. When power up is under soft-start control, the output voltage rises to the set-point at a quicker and more linear rate.

From the moment a valid input voltage is applied, the soft-start control introduces a short time delay (a period typically between 10 ms and 15 ms) before allowing the output voltage to rise.

The output then progressively rises to the setpoint voltage of the module. Figure 12 shows the soft-start power-up characteristic of the PTH08T250W operating from a 5-V input bus and configured for a 1.2-V output. The waveforms were measured with a 25-A constant current load and the Auto-Track feature disabled. The initial rise in input current when the input voltage first starts to rise is the charge current drawn by the input capacitors. Power-up is complete within 30 ms.