TIDT281 June   2022

 

  1.   Description
  2.   Features
  3.   Applications
  4. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Considerations
    3. 1.3 Dimensions
  5. 2Testing and Results
    1. 2.1 Efficiency Graphs
      1. 2.1.1 24-V Output Voltage
      2. 2.1.2 48-V Output Voltage
    2. 2.2 Loss Graphs
      1. 2.2.1 24-V Output Voltage
      2. 2.2.2 48-V Output Voltage
    3. 2.3 Load Regulation
      1. 2.3.1 24-V Output Voltage
      2. 2.3.2 48-V Output Voltage
    4. 2.4 Line Regulation
      1. 2.4.1 24-V Output Voltage
      2. 2.4.2 48-V Output Voltage
    5. 2.5 Thermal Images
    6. 2.6 Bode Plots
      1. 2.6.1 60-V Input Voltage and 24-V Output Voltage
      2. 2.6.2 30-V Input Voltage and 48-V Output Voltage
      3. 2.6.3 Loop Variants
  6. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 24-V Output Voltage, 30-V Input Voltage (Duty Cycle 80%)
        1. 3.1.1.1 Diode D1
        2. 3.1.1.2 Transistor Q2
          1. 3.1.1.2.1 Drain - GND
          2. 3.1.1.2.2 Gate - GND
        3. 3.1.1.3 Diode D2
        4. 3.1.1.4 Transistor Q1
          1. 3.1.1.4.1 Source - VIN
          2. 3.1.1.4.2 Gate - Source
      2. 3.1.2 24-V Output Voltage; 60-V Input Voltage
        1. 3.1.2.1 Diode D2
        2. 3.1.2.2 Transistor Q1
          1. 3.1.2.2.1 Source - VIN
          2. 3.1.2.2.2 Gate-Source
      3. 3.1.3 48-V Output Voltage; 30-V Input Voltage (Maximum Stress)
        1. 3.1.3.1 Diode D1
        2. 3.1.3.2 Transistor Q2
          1. 3.1.3.2.1 Drain-GND
          2. 3.1.3.2.2 Gate-GND
        3. 3.1.3.3 Diode D2
        4. 3.1.3.4 Transistor Q1
          1. 3.1.3.4.1 Source - VIN
          2. 3.1.3.4.2 Gate - Source
      4. 3.1.4 48-V Output Voltage; 60-V Input Voltage
        1. 3.1.4.1 Diode D1
        2. 3.1.4.2 Transistor Q2
          1. 3.1.4.2.1 Drain - GND
          2. 3.1.4.2.2 Gate - GND
        3. 3.1.4.3 Diode D2
        4. 3.1.4.4 Transistor Q1
          1. 3.1.4.4.1 Source - VIN
          2. 3.1.4.4.2 Gate - Source
    2. 3.2 Output Voltage Ripple
      1. 3.2.1 24-V Output Voltage
      2. 3.2.2 48-V Output Voltage
    3. 3.3 Input Voltage Ripple
      1. 3.3.1 24-V Output Voltage
      2. 3.3.2 48-V Output Voltage
    4. 3.4 Load Transients
      1. 3.4.1 24-V Output Voltage
        1. 3.4.1.1 30-V Input Voltage
        2. 3.4.1.2 60-V Input Voltage
      2. 3.4.2 48-V Output Voltage
        1. 3.4.2.1 30-V Input Voltage
        2. 3.4.2.2 60-V Input Voltage
    5. 3.5 Start-Up Sequence
      1. 3.5.1 24-V Output Voltage
        1. 3.5.1.1 30-V Input Voltage
        2. 3.5.1.2 60-V Input Voltage
      2. 3.5.2 48-V Output Voltage
        1. 3.5.2.1 30-V Input Voltage
        2. 3.5.2.2 60-V Input Voltage
    6. 3.6 Shutdown Sequence
      1. 3.6.1 24-V Output Voltage
        1. 3.6.1.1 30-V Input Voltage
        2. 3.6.1.2 60-V Input Voltage
      2. 3.6.2 48-V Output Voltage
        1. 3.6.2.1 30-V Input Voltage
        2. 3.6.2.2 60-V Input Voltage

1.2 Considerations

Unless otherwise indicated, all measurements were done by 0.6 A adjusted by a variable resistor.

The circuit starts with switching at 28 V and stops with switching around 25.7 V.

The prototype worked at a measured switching frequency of 300 kHz and soft start set to 12 ms.

Note:

By inserting the jumper J3, the output voltage can be switched from 24 V to 48 V.