TIDT346 august   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 Efficiency Data
      1. 2.2.1 6-V Input Voltage
      2. 2.2.2 12-V Input Voltage
      3. 2.2.3 16-V Input Voltage
    3. 2.3 Thermal Images
    4. 2.4 Bode Plots
      1. 2.4.1 4.5-V Input Voltage
      2. 2.4.2 6-V Input Voltage
      3. 2.4.3 12-V Input Voltage
  7. 3Waveforms
    1. 3.1 Switching
      1. 3.1.1 6-V Input Voltage and 1-A Load
      2. 3.1.2 16-V Input Voltage and 1-A Load
      3. 3.1.3 Overshoot at VIN 12 V and 1-A Load Current
      4. 3.1.4 Undershoot at 12 VIN and 1-A Load Current
    2. 3.2 Output Voltage Ripple
    3. 3.3 Input Voltage Ripple
    4. 3.4 Load Transients
      1. 3.4.1 6-V Input Voltage
      2. 3.4.2 16-V Input Voltage
    5. 3.5 Start-Up Sequence (1-A Load)
    6. 3.6 Shutdown Sequence
      1. 3.6.1 No Load
      2. 3.6.2 1-A Load

Description

This design showcases a 1-A (1.5-A peak) output current nonsynchronous SEPIC converter based on LM51561, which covers an input voltage range of 6 V to 36 V with an output voltage of 12 V. The efficiency reaches up to 90.5% at 12-V input voltage. The design can operate down to 4.5 V to support automotive cranking.

The 2-MHz switching frequency allows the use of a smaller inductor and therefore enables a smaller circuit size.