Boost DC-DC (Direct Current-Direct Current) converter and method

Abstract

The invention relates to the field of electrics and provides a boost DC-DC (Direct Current-Direct Current) converter and a method in order to solve the problems of overlarge dimension and long starting time of the converter in the prior art. The device comprises a clock conversion unit, a multi-path power supply driving unit and a circuit control unit, wherein the clock conversion unit is used for driving a power switch unit at the starting stage; the multi-path power supply driving unit is used for detecting whether VOUT (output voltage) reaches a first preset value or not; if the VOUT reaches the first preset value, the VOUT is selected and output to serve as the power supply voltage of the power switch unit, otherwise, VIN (input voltage) is selected and output to serve as the power supply voltage of the power switch unit; and the circuit control unit is used for judging whether the VOUT reaches a second preset value or not; if the VOUT reaches the second preset value, the clock conversion unit is shut off; and the power switch unit is driven by the circuit control unit to continue to boost and keep the VOUT to a third preset value. The embodiment of the invention has the advantages that the circuit dimension of the DC-DC converter can be reduced, and the starting time under the low input voltage is shortened.

Description

technical field [0001] The invention relates to the field of electricity, in particular to a step-up DC-DC converter and method. Background technique [0002] As the concept of energy saving and environmental protection is deeply rooted in the hearts of the people, the use of solar photovoltaic cells has gradually been generally recognized by the society. However, it is not feasible to directly provide weak solar photovoltaic cells (0.3-0.5V) to current portable products, so the use of boost (Boost) DC-DC converters will be inevitable. [0003] Such as figure 1 Shown is a structural block diagram of a Boost type DC-DC converter in the prior art. In the start-up phase, the clock signal output by the oscillator (OSC) passes through the driver 1 (BUF1) and directly drives the power device NMOS1 to achieve the purpose of starting and increasing the output voltage VOUT. However, when a low-voltage power supply device, such as a solar photovoltaic cell (0.3-0.5V), is used as th...

AI Technical Summary

Problems solved by technology

[0007] Embodiments of the present invention provide a step-up DC-DC converter and method, which are used to solve the problem of selecting the input power supply voltage VIN or the output voltage VOUT as the power supply voltage caused by the need for multiple high-power switches in the prior art. , so as to solve the problem of high energy consumption caused by the oversized converter, and at the same time solve the problem of slow start-up time when starting at low voltage

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