TIDT328 april   2023

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Considerations
    3. 1.3 Dimensions
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Load Regulation
    3. 2.3 Thermal Images
      1. 2.3.1 Unmodulated 60 VDC - Output
      2. 2.3.2 60 VAC - Output Modulated With 120-Hz Sinus (0 V – 5 V)
      3. 2.3.3 Conclusion
    4. 2.4 Bode Plot at Maximum Duty Cycle
  7. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 Transistor Q1 Operating in Deep DCM
        1. 3.1.1.1 Drain to Source
        2. 3.1.1.2 Gate to Source
      2. 3.1.2 Diode D3 (Referenced to VOUT)
    2. 3.2 Output Voltage Ripple
    3. 3.3 Input Voltage Ripple
    4. 3.4 Start-Up Sequence
    5. 3.5 Shutdown Sequence
  8.   A Modulating the Output Voltage
    1.     A.1 Revision B
      1.      A.1.1 Bode Plot
      2.      A.1.2 Simulation
      3.      A.1.3 Measured Waveforms
        1.       A.1.3.1 Sinus 40 Hz
        2.       A.1.3.2 Sinus 100 Hz
        3.       A.1.3.3 Sawtooth 1
        4.       A.1.3.4 Sawtooth 2
        5.       A.1.3.5 Pure Triangle
        6.       A.1.3.6 Conclusion
    2.     A.2 Revision C
      1.      A.2.1 Bode Plot
      2.      A.2.2 Measured Waveforms
        1.       A.2.2.1 Sinus 120 Hz
        2.       A.2.2.2 Sawtooth 1
        3.       A.2.2.3 Sawtooth 2
        4.       A.2.2.4 Pure Triangle
      3.      A.2.3 Analysis Capacitor 1 µF, 100 V, X7R, 1206
        1.       A.2.3.1 DC-Bias
        2.       A.2.3.2 Resistance (ESR)
        3.       A.2.3.3 Reactance
        4.       A.2.3.4 Impedance

1.2 Considerations

During operation, the circuit started to switch around 8.9 V and the switching stops at around 8.2 V.

A resistor was used as load. Unless otherwise indicated, the output current was adjusted to 0.3 A and the input voltage was set to 12-V nominal input voltage.

For the waveforms in Section 3, the modulating input J201 is shorted. The output is set to 60 VDC and maximum output power is 18 W.

The prototype device NVMFS021N10MCL was used as Q1, due to availability.