Adaptive current detection circuit applied to wide-conversion ratio boost converter

Abstract

The invention belongs to the technical field of integrated circuits, in particular to an adaptive current detection circuit applied to a wide-conversion ratio boost converter. The circuit comprises a single-period double-sampling circuit, a reference level generating circuit and an adaptive gain circuit, wherein the single-period double-sampling circuit is used for generating two sampling signals, namely an inductive current signal and an output voltage signal, and providing the signals for the self-adaptive gain circuit; the reference level generating circuit is used for generating a reference level and providing the reference level for the self-adaptive gain circuit; and the adaptive gain circuit generates a needed inductive current sampling signal which is adaptive to the output voltage by using the signals provided by the single-period double-sampling circuit and the reference level generating circuit. The adaptive current detection circuit avoids a method for implementing different conversion ratios by selecting an off-chip compensating network. Therefore, the adaptive current detection circuit has the advantages of making the compensating network become simple and integrated inside a chip, reducing the number of off-chip elements, meeting the requirement on portability, reducing the cost and having good application prospect.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to a step-up DC-DC converter with a wide conversion ratio. Background technique [0002] DC-DC Converter (DC-DC Converter) is widely used in various electronic systems, especially the inductive-based DC-DC converter, due to its advantages of high efficiency and large output current capability, it is the most widely used. According to the relationship between the input voltage and the output voltage of the converter, it can be divided into buck type (BUCK), boost type (BOOST) and buck-boost type (BUCK-BOOST). The step-up converter is used to increase the power supply voltage to supply power to various circuit modules that require higher voltage power supply. For example, in the display screen of some handheld devices, 4 LED backlights connected in series need a voltage of about 12 volts, while the output voltage of a general battery is only 2.7V~5.5V. This r...

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Problems solved by technology

[0004] The BOOST type converter contains two poles and a zero point in the right half plane in the transfer function of its power stage, which makes the compensation network more complicated than the BUCK type under the traditional voltage control mode and current control mode, and it is difficult to operate in a wide Keep the system stable and good transient response under the conversion ratio

General products are implemented by selecting different compensation networks off-chip under different conversion ratios, making the compensation network unable to be integrated on-chip, increasing the number of off-chip components and increasing the cost

In addition, in the BOOST circuit, due to its discontinuous output current, the hysteresis control cannot be directly adopted

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