阅读说明：本技术 一种电流过零点检测电路 (Current zero crossing point detection circuit ) 是由 冯卫宏 于 2019-09-17 设计创作，主要内容包括：本发明公开了一种电流过零点检测电路,其特征在于,包括检测电路和增益电路,其特征在于,所述增益电路包括：放大器、晶体管和电阻；所述检测电路还包括所述控制电路还包括滤波器FL,所述滤波器FL的输出端电连接所述开关负载栅极,输入端连接电荷泵电路CP的输出端,其中,所述放大器具有正相输入端、反相输入端和放大输出端,其正相输入端耦接所述电阻第四端以接收所述第一平均信号,所述过零点检测电路包括信号输入端、采样保持模块、第二基准电压模块和第二比较器,所述采样保持模块和第二基准电压模块相连,且所述采样保持模块的一端与信号输入端相连,所述第二基准电压模块的一端作为第二比较器的第一输入端,所述信号输入端作为第二比较器的第二输入端。(The invention discloses a current zero-crossing detection circuit, which is characterized by comprising a detection circuit and a gain circuit, wherein the gain circuit comprises: an amplifier, a transistor, and a resistor; the detection circuit further comprises a filter FL, an output end of the filter FL is electrically connected to the switching load gate, an input end of the filter FL is connected to an output end of the charge pump circuit CP, wherein the amplifier has a positive phase input end, a negative phase input end and an amplification output end, the positive phase input end of the amplifier is coupled to the fourth end of the resistor to receive the first average signal, the zero crossing point detection circuit comprises a signal input end, a sample-and-hold module, a second reference voltage module and a second comparator, the sample-and-hold module is connected to the second reference voltage module, one end of the sample-and-hold module is connected to the signal input end, one end of the second reference voltage module serves as a first input end of the second comparator, and the signal input end serves as a second input end of the second comparator.)

1. A current zero crossing detection circuit comprising a detection circuit and a gain circuit, wherein the gain circuit comprises: an amplifier, a transistor, and a resistor; the detection circuit further comprises a filter FL, an output end of the filter FL is electrically connected to the switching load gate, an input end of the filter FL is connected to an output end of the charge pump circuit CP, wherein the amplifier has a positive phase input end, a negative phase input end and an amplification output end, the positive phase input end of the amplifier is coupled to the fourth end of the resistor to receive the first average signal, the zero crossing point detection circuit comprises a signal input end, a sample-and-hold module, a second reference voltage module and a second comparator, the sample-and-hold module is connected to the second reference voltage module, one end of the sample-and-hold module is connected to the signal input end, one end of the second reference voltage module serves as a first input end of the second comparator, and the signal input end serves as a second input end of the second comparator.

Technical Field

The invention relates to the technical field of circuits, in particular to a current zero crossing point detection circuit.

Background

The low dropout regulator is an important component in an on-chip power management system module, and is widely applied due to the advantages of small required input/output voltage difference, small area, high current utilization rate, easy integration and the like. However, when the external load changes, the output voltage will have a spike and a transient response time tr is needed to return to the steady state. The presence of these spikes will have a fatal effect on the performance of the powered module, particularly an analog module. In addition, to ensure the normal operation of the low dropout regulator, an off-chip coupling capacitor with special parameters (Cout and effective series resistance RESR) is usually required to be externally connected.

In view of the above, the present invention provides a simple and effective method for improving transient response performance of a linear voltage regulator, which simplifies the circuit structure and reduces power consumption while achieving high performance.

Disclosure of Invention

In order to solve the technical problem, the invention provides a current zero crossing point detection circuit.

The invention provides a current zero crossing point detection circuit, compared with the related technology, the technical scheme of the invention is as follows:

a current zero crossing detection circuit comprising a detection circuit and a gain circuit, wherein the gain circuit comprises: an amplifier, a transistor, and a resistor; the detection circuit further comprises a filter FL, an output terminal of the filter FL is electrically connected to the switching load gate, an input terminal of the filter FL is connected to an output terminal of the charge pump circuit CP, wherein the amplifier has a positive input terminal, a negative input terminal and an amplification output terminal, the positive input terminal of the amplifier is coupled to the fourth terminal of the resistor to receive the first average signal, the zero crossing point detection circuit comprises a signal input terminal, a sample-and-hold module, a second reference voltage module and a second comparator, the sample-and-hold module is connected to the second reference voltage module, one end of the sample-and-hold module is connected to the signal input terminal, one end of the second reference voltage module is used as a first input terminal of the second comparator, and the signal input terminal is used as a second input terminal of the second comparator

The invention has the following beneficial effects: the first non-dominant pole of the low dropout linear regulator can be accurately offset by the dynamic zero, and the second non-dominant pole can be offset by the zero generated by the external capacitor. The whole system is thus equivalent to a single-pole system, and the unity gain frequency is significantly improved.

Drawings

Fig. 1 is a schematic structural diagram of a current zero-crossing detection circuit according to the present invention.

Detailed Description

The invention will be further explained with reference to the drawings and the embodiments.

The invention provides a current zero crossing point detection circuit, which is characterized by comprising a detection circuit and a gain circuit, wherein the gain circuit comprises: an amplifier, a transistor, and a resistor; the detection circuit further comprises a filter FL, an output end of the filter FL is electrically connected to the switching load gate, an input end of the filter FL is connected to an output end of the charge pump circuit CP, wherein the amplifier has a positive phase input end, a negative phase input end and an amplification output end, the positive phase input end of the amplifier is coupled to the fourth end of the resistor to receive the first average signal, the zero crossing point detection circuit comprises a signal input end, a sample-and-hold module, a second reference voltage module and a second comparator, the sample-and-hold module is connected to the second reference voltage module, one end of the sample-and-hold module is connected to the signal input end, one end of the second reference voltage module serves as a first input end of the second comparator, and the signal input end serves as a second input end of the second comparator.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.