Research Of Interleaved Synchronous Buck Tracking Sources

This paper researches the control scheme of interleaved synchronous Bucktracking source to promote its tracking bandwidth. According to existing tracksource scheme, it can be divided into two kinds: switching power supply andswitch-linear hybrid. Each type of tracking source has its support from publishedliterature.According to the results of these literature and theoretical analysis,advantages and disadvantages of all kinds of tracking source are summarized.The voltage type PWM control for interleaved synchronous Buck is researched.Phase-shift circuit adopts the method of phase shift all-pass filter to getphase-shifting triangle wave. By comparing interleaved and single-phasesynchronous Buck, verifies that interleaved synchronous Buck can improve trackingbandwidth. Based on the research of the output filter, the optimization method toimprove tracking bandwidth of tracking source is summarized.The simulation of the single phase and multiphase peak-current control isfinished. In the multiphase peak-current control, the method of phase-shift slopecompensation is used. Compare the simulation result with the result of the voltagetype PWM control, conclusions can be drawn that current mode control trackingsource has a tracking bandwidth enhancement and the phase delay is small.A novel V2Ic control method is used in tracking source. A non-invasive sensorto measure the current of the output capacitor is designed.V2Ic control can be wellapplied to the single-phase and interleaved synchronous synchronous Buck's control.It has a higher tracking bandwidth than the peak-current control. When the numberof phase is high, it avoids measuring current in each phase as in the peak-currentcontrol, which lead to complex circuit.The paper compares the voltage type PWM control, the peak-current controland the V2Ic control through the analysis of frequency tracking. The three kinds ofcontrol modes are compared in tracking bandwidth, phase shift and linearity by theresult of the closed loop frequency sweep, which confirms the obviously increase oftracking bandwidth by using current mode control and shows the advantages of V2Iccontrol.