TIDT385 May   2024

 

  1.   1
  2.   Description
  3.   Features
  4.   Applications
  5. 1Test Prerequisites
    1. 1.1 Voltage and Current Requirements
    2. 1.2 Required Equipment
    3. 1.3 Considerations
    4. 1.4 Dimensions
  6. 2Testing and Results
    1. 2.1 Efficiency Graphs
    2. 2.2 Efficiency Data
    3. 2.3 Thermal Images
    4. 2.4 Bode Plots
  7. 3Waveforms
    1. 3.1 Switching Waveforms
    2. 3.2 Voltage Ripple
    3. 3.3 Load Transients
    4. 3.4 Start-Up Sequence
    5. 3.5 Input Telemetry
    6. 3.6 Smooth Transition

3.6 Smooth Transition

The smooth transition (no output voltage interruption) is shown in Figure 3-11 through Figure 3-28. For all waveforms:

  1. Channel 1 is output voltage, 1V / div
  2. Channel 2 is PoE Port 1 input current, 500mA / div
  3. Channel 4 is PoE Port2 input current, 500mA / div
  4. The time base is 100ms / div
  5. For all Expected Results, the output voltage remains within transient limits
  6. Standby indicates that the PoE PD MPS (maintain power signature) is active
Table 3-2 Transitions Between Two PoE Inputs
Case Initial State Transition Expected Result
1 PoE Port 1 connected Add PoE Port 2 PoE Port 1 continues to power converter. PoE Port 2 connects in standby
2 PoE Port 2 connected Add PoE Port 1 Power transitions to PoE Port 1. PoE Port 2 stays connected in standby.
3 PoE Port 1 and Port 2 connected. PoE Port 1 powers converter. PoE Port 2 connected in standby. Remove PoE Port 1 Power transitions to PoE Port 2
4 PoE Port 1 and Port 2 connected. PoE Port 1 powers converter, PoE Port 2 connected in standby. Remove PoE Port 2 PoE Port 1 continues to power converter
PMP23366 Case 1 Figure 3-11 Case 1
PMP23366 Case 2 Figure 3-12 Case 2
PMP23366 Case 3 Figure 3-13 Case 3
PMP23366 Case 4 Figure 3-14 Case 4
Table 3-3 Transitions Between Single PoE Input and Auxiliary
Case Initial State Transition Expected Result
5 PoE Port 1 connected Add auxiliary Auxiliary provides power. PoE Port 1 stays connected in standby.
6 PoE Port 2 connected Add auxiliary Auxiliary provides power. PoE Port 2 stays connected in standby.
7 Auxiliary connected Add PoE Port 1 Auxiliary continues to provide power. PoE Port 1 connects in standby.
8 Auxiliary connected Add PoE Port 2 Auxiliary continues to provide power. PoE Port 2 connects in standby.
9 PoE Port 1 and auxiliary connected Remove auxiliary Power transitions to PoE Port 1
10 PoE Port 1 and auxiliary connected Remove PoE Port 1 Auxiliary continues to provide power.
11 PoE Port 2and auxiliary connected Remove auxiliary Power transitions to PoE Port 2
12 PoE Port 2and auxiliary connected Remove PoE Port 2 Auxiliary continues to provide power.
PMP23366 Case 5 Figure 3-15 Case 5
PMP23366 Case 6 Figure 3-16 Case 6
PMP23366 Case 7 Figure 3-17 Case 7
PMP23366 Case 8 Figure 3-18 Case 8
PMP23366 Case 9 Figure 3-19 Case 9
PMP23366 Case 10 Figure 3-20 Case 10
PMP23366 Case 11 Figure 3-21 Case 11
PMP23366 Case 12 Figure 3-22 Case 12
Table 3-4 Transitions Between Dual PoE Inputs and Auxiliary
Case Initial State Transition Expected Result
13 PoE Port 1, PoE Port 2 and Auxiliary connected Remove Auxiliary Power transitions to PoE Port 1. PoE Port 2 stays connected in standby.
14 PoE Port 1, PoE Port 2 and Auxiliary connected Remove PoE Port 1 Auxiliary continues to provide power. PoE Port 2 stays connected in standby.
15 PoE Port 1, PoE Port 2 and Auxiliary connected Remove PoE Port 2 Auxiliary continues to provide power. PoE Port 1 stays connected in standby.
16 PoE Port 1 and PoE Port 2 connected Add Auxiliary Power transitions to auxiliary. PoE Port 1 and Port 2 stay connected in standby.
17 PoE Port 1 and Auxiliary connected Add PoE Port 2 Auxiliary continues to provide power. PoE Port 1 stays connected in standby. PoE Port 2 connects in standby.
18 PoE Port 2 and Auxiliary connected Add PoE Port 1 Auxiliary continues to provide power. PoE Port 2 stays connected in standby. PoE Port 1 connects in standby.
PMP23366 Case 13 Figure 3-23 Case 13
PMP23366 Case 14 Figure 3-24 Case 14
PMP23366 Case 15 Figure 3-25 Case 15
PMP23366 Case 16 Figure 3-26 Case 16
PMP23366 Case 17 Figure 3-27 Case 17
PMP23366 Case 18 Figure 3-28 Case 18