SLUUCI9A January   2022  – December 2022 UCC28781

 

  1.   Abstract
  2.   Trademarks
  3. 1 Introduction
  4. 2 General Texas Instruments High Voltage Evaluation (TI HV EVM) User Safety Guidelines
  5. 3 Description of EVM
  6. 4 Electrical Performance Specifications of EVM
  7. 5 Schematic Diagram of EVM
  8. 6 Operating the EVM from a DC or an AC Source
    1. 6.1 Typical Applications
    2. 6.2 Using the EVM with a DC Voltage Source
    3. 6.3 Using the EVM with an AC Voltage Source
  9. 7 Test Set-ups
    1. 7.1 Test Set-up Requirements
      1. 7.1.1 Test Set-up Requirements for DC Input
      2. 7.1.2 Test Set-up Requirements for AC Input
    2. 7.2 Test Set-up Diagrams
    3. 7.3 Terminals and Test Points
  10. 8 Performance Data and Typical Characteristic Curves
    1. 8.1 Table of Efficiency Measurements with DC Input
    2. 8.2 Table of Efficiency Measurements with AC Input
    3. 8.3 Efficiency Graphs with DC Input Voltage (Typical Results)
    4. 8.4 Switching Frequencies in Various Operating Modes
    5. 8.5 Key Switching Waveforms and Operating Mode Load Current
    6. 8.6 Thermal Images at Full Load (15 V, 4.0 A) with DC and AC Inputs
  11. 9 Transformer Details
  12. 10EVM Assembly and Layout
  13. 11List of Materials
  14. 12Revision History

8.5 Key Switching Waveforms and Operating Mode Load Current

This section shows a table of typical load-current ranges within each operating mode in this design, at Vin = 250 VDC and IFL_HI range as an example. Following the table are typical waveforms seen while in each of the operating modes of Table 8-3. Hysteresis between modes results in differences between the modes' current ranges when load is decreasing compared to when load is increasing.

  • AAM: Adaptive Amplitude Modulation
  • ABM: Adaptive Burst Mode
  • LPM: Low Power Mode
  • SBP1: First Standby Power Mode
  • SBP2: Second Standby Power Mode

Table 8-3 Operating Modes and Load Currents at 250-VDC Input; Output in IFL_HI Range
Mode: AAMABMLPMSBP1SBP2
Typical Load Current (Decreasing) 4.0 A to 1.3 A 1.3 A to 0.41 A 0.41 A to 0.22 A 0.22 A to 0.09 A 0.09 A to 0 A
Typical Load Current (Increasing)1.8 A to 4.0 A0.53 A to 1.8 A0.23 A to 0.53 A0.14 A to 0.23 A 0 A to 0.14 A
Burst Frequency, fBUR (pulses per burst) Not Applicable > 25 kHz
(9 to 2 pulses)		 about 25 kHz
(2 pulses)		 8.5 kHz to 25 kHz
(2 pulses)		 < 8.5 kHz
(2 pulses)

In the following waveforms, Ch4 (green) = Transformer Primary Winding Current at 1 A/div, Ch2 (blue) = VDS of SR-Mosfet at 20 V/div (AC-coupled).

GUID-20220107-SS0I-6M5C-ZPJX-8HHPT5P2TQFZ-low.pngFigure 8-8 Typcial Waveform in AAM Operation (Sweep = 10 μs/div)
GUID-20220107-SS0I-PMS9-3LBX-Q9LBBQ71CRML-low.pngFigure 8-10 Typical Waveform in LPM Operation (Sweep = 10 μs/div)
GUID-20220107-SS0I-47DM-LF6W-1JSTVLJVZDZS-low.pngFigure 8-9 Typical Waveform in ABM Operation (Sweep = 10 μs/div)
GUID-20220107-SS0I-MCNC-N0RT-CQRNHKHCKWQ5-low.pngFigure 8-11 Typical Waveform in SBP1 Operation (Sweep = 10 μs/div)
GUID-20220107-SS0I-P3BS-W448-NMW7PFGTHVVQ-low.pngFigure 8-12 Typical Waveform in SBP2 Operation (Sweep = 100 μs/div)
GUID-20220107-SS0I-FWD3-JSVW-D55ZCXJGKBGS-low.pngFigure 8-13 Typical Waveform in SBP2 Operation, Burst Detail (Sweep = 1 μs/div)