Voltage conversion circuit and its control method

Abstract

The present disclosure provides a control method for a voltage conversion circuit, which is applied to a voltage conversion circuit. The voltage conversion circuit includes an electrically coupled DC voltage input terminal, a transformer primary switch network, a resonant inductor, a transformer, a transformer secondary switch network, a DC The voltage output terminal, the resonant inductance is connected in series with the transformer, and the voltage conversion circuit also includes a resonant capacitor resonating with the resonant inductance; the control method includes controlling the switching elements in the primary switch network of the transformer and the switch network of the secondary side of the transformer, so that the voltage conversion circuit The value range of the ratio Ton / Tr of the total on-time Ton of the voltage conversion circuit to the resonance period Tr of the voltage conversion circuit is (0,1.8)U(2.7,3.7)U(4.8,5.5), and the quality factor Q of the voltage conversion circuit ≤5. The control method provided by the embodiments of the present disclosure can reduce conduction loss and switching loss of the voltage conversion circuit, thereby improving efficiency and reducing cost.

Description

technical field [0001] The present disclosure relates to the technical field of power circuits, in particular, to a voltage conversion circuit and a control method thereof. Background technique [0002] figure 1 Shown is a two-stage cascaded converter structure, which usually adopts the working mode of reducing voltage first and then regulating voltage. For example, the first-stage converter can use a high-efficiency DC transformer to reduce the input 48V bus voltage (Uin) to a lower intermediate bus voltage (Uib), such as 4V, with an efficiency of η1, and the second-stage converter uses a multi-phase interleaved The parallel-connected BUCK converter controls the BUCK output voltage Uo through closed-loop control, and the efficiency is η2, which ensures the power supply of the load (such as a processor chip). [0003] figure 2 shown as figure 1 Typical topology of the first-stage converter of a two-stage converter—LLC series resonant circuit, Figure 3A ~ Figure 3C yes...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present disclosure is to provide a voltage conversion circuit and its control method, which are used to overcome at least to some extent the problem of large circuit loss caused by the large effective value of the current of the resonant circuit itself due to the limitations and defects of the related technology

Images