TIDT260 March   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
    2. 2.2 Load Regulation
    3. 2.3 Line Regulation
    4. 2.4 Thermal Images
      1. 2.4.1 8-V Input Voltage
      2. 2.4.2 18-V Input Voltage
    5. 2.5 Bode Plots
  6. 3Waveforms
    1. 3.1 Switching
    2. 3.2 Output Voltage Ripple
    3. 3.3 Input Voltage Ripple
    4. 3.4 Load Transients
    5. 3.5 Start-Up Sequence
    6. 3.6 Shutdown Sequence
    7. 3.7 Spread Spectrum Feature

3.7 Spread Spectrum Feature

The spread spectrum features are demonstrated in the following figures.

GUID-20220221-SS0I-NQZV-QBXB-TWDGJHJXDSWZ-low.jpg Figure 3-15 Disabled, MODE Tied to AGnd Using a 0-Ω Resistor
GUID-20220221-SS0I-WNPW-XHTC-QNCLPQNDLKLB-low.jpg Figure 3-16 Enabled, MODE Across R10 = 37.4-kΩ to AGnd

DRSS, pseudo-dual random spread spectrum: low-frequency triangular switching frequency modulation, and triangular control voltage varies in its modulation frequency itself. In addition this control voltage is superimposed with a random noise, results in best noise reduction at switching frequency and closer harmonics as well as in the high RF range FM band and beyond.