TIDT347A November   2023  – October 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
    5. 1.5 Test Setup
  6. 2Testing and Results
    1. 2.1 Efficiency Data
    2. 2.2 Efficiency Graphs
    3. 2.3 Thermal Images
  7. 3Waveforms
    1. 3.1 Charging Waveform
    2. 3.2 Switching Waveform
    3. 3.3 Short-Circuit Protection
  8.   Trademarks

3.2 Switching Waveform

Figure 3-5 through Figure 3-8 show the power stage waveform at different working modes in the BQ25756 device among buck mode, buck-boost mode, and boost mode with seamless transition. The switching frequency is set to 300kHz.

PMP41083 Buck Mode
Blue: buck leg SW point, Purple: boost leg SW point
Figure 3-5 Buck Mode
PMP41083 Buck-Boost Mode
Blue: Buck Leg SW point, Purple: Boost leg SW Point
Figure 3-6 Buck-Boost Mode
PMP41083 Boost Mode
Blue: buck leg SW point, Purple: boost leg SW point
Figure 3-7 Boost Mode
PMP41083 Switching Leg Waveform at Vsys = 20V, Vbat = 40V Fast Charging Mode, fSW = 300kHz Figure 3-8 Switching Leg Waveform at Vsys = 20V, Vbat = 40V Fast Charging Mode, fSW = 300kHz