阅读说明：本技术 一种零点检测电路 (Zero point detection circuit ) 是由 李政 于 2019-09-18 设计创作，主要内容包括：本发明公开了一种零点检测电路,其特征在于,包括负载电源电路、分压电阻、开关管、过零点检测电路、负载调整补偿电路,所述负载电源电路包括负载、二极管和电感,且所述负载、二极管和电感串联形成环形电路,所述负载电源电路的一端与工作电压输入端相连接,所述负载调整补偿电路包括：电压缓冲器,以输出电流驱动能力增大的该第三平均信号至所述开关第七端所述负载电源电路的另一端与开关管的第一端、分压电阻的第一端相连接,所述分压电阻的第二端连同所述开关管的第二端接地,利用所述开关管对于负载电压进行控制,所述分压电阻的分压端与过零点检测电路的信号输入端相连接,利用过零点检测电路获得二极管的电流过零点。(The invention discloses a zero point detection circuit, which is characterized by comprising a load power supply circuit, a divider resistor, a switching tube, a zero-crossing point detection circuit and a load adjustment compensation circuit, wherein the load power supply circuit comprises a load, a diode and an inductor, the load, the diode and the inductor are connected in series to form an annular circuit, one end of the load power supply circuit is connected with a working voltage input end, and the load adjustment compensation circuit comprises: and the voltage buffer is used for outputting the third average signal with the increased current driving capability to the seventh end of the switch, the other end of the load power supply circuit is connected with the first end of a switch tube and the first end of a divider resistor, the second end of the divider resistor and the second end of the switch tube are grounded, the switch tube is used for controlling the load voltage, the divider end of the divider resistor is connected with the signal input end of the zero-crossing detection circuit, and the zero-crossing detection circuit is used for obtaining the current zero-crossing point of the diode.)

1. The utility model provides a zero point detection circuit, its characterized in that, includes load power supply circuit, divider resistance, switch tube, zero crossing detection circuit, load adjustment compensating circuit, load power supply circuit includes load, diode and inductance, just load, diode and inductance are established ties and are formed ring circuit, load power supply circuit's one end is connected with the operating voltage input end, load adjustment compensating circuit includes: and the voltage buffer is coupled between the filtering output end of the third filtering circuit and the seventh end of the switch, receives the third average signal, increases the current driving capability of the third average signal, outputs the third average signal with the increased current driving capability to the seventh end of the switch, connects the other end of the load power circuit with the first end of the switch tube and the first end of the divider resistor, connects the second end of the divider resistor and the second end of the switch tube to the ground, controls the load voltage by using the switch tube, connects the voltage dividing end of the divider resistor with the signal input end of the zero-crossing detection circuit, and obtains the current zero-crossing point of the diode by using the zero-crossing detection circuit.

2. The zero-point detection circuit of claim 1, wherein the voltage-dividing resistor transmits the third average signal to an eighth terminal of the switch to provide the sampling signal when the high-side switch is turned on.

Technical Field

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

Background

Generally, a control circuit in a switching type voltage conversion circuit controls switching of a switching unit based on a feedback signal reflecting an output voltage thereof and a reference signal representing a desired value of the output voltage thereof to adjust the output voltage in time according to a load change. The reference signal is typically provided by circuitry integrated within the switch-type voltage conversion circuit chip and is thus referenced to ground potential with an internal reference ground, with the offset voltage being relative to the ground pin. When the load current of the switching type voltage conversion circuit changes, the switching current of the switching unit changes immediately, thereby causing the offset voltage to change, and then the reference signal for referring to the regulation of the output voltage also changes with respect to the ground pin, so that the load regulation rate of the switching type voltage conversion circuit becomes poor.

Accordingly, it is desirable to compensate for the offset voltage of the reference signal with respect to the ground pin such that the offset voltage of the reference signal with respect to the ground pin is substantially cancelled to achieve load regulation compensation for the switching mode voltage converting circuit such that the load regulation rate of the switching mode voltage regulator is substantially unaffected by variations in the offset voltage caused by variations in the load current.

Disclosure of Invention

In order to solve the above technical problems, the present invention provides a zero point detection circuit.

Compared with the related art, the invention provides a zero detection circuit, and the technical scheme of the invention is as follows:

the utility model provides a zero point detection circuit, its characterized in that, includes load power supply circuit, divider resistance, switch tube, zero crossing detection circuit, load adjustment compensating circuit, load power supply circuit includes load, diode and inductance, just load, diode and inductance are established ties and are formed ring circuit, load power supply circuit's one end is connected with the operating voltage input end, load adjustment compensating circuit includes: and the voltage buffer is coupled between the filtering output end of the third filtering circuit and the seventh end of the switch, receives the third average signal, increases the current driving capability of the third average signal, outputs the third average signal with the increased current driving capability to the seventh end of the switch, connects the other end of the load power circuit with the first end of the switch tube and the first end of the divider resistor, connects the second end of the divider resistor and the second end of the switch tube to the ground, controls the load voltage by using the switch tube, connects the voltage dividing end of the divider resistor with the signal input end of the zero-crossing detection circuit, and obtains the current zero-crossing point of the diode by using the zero-crossing detection circuit.

In a further aspect, the divider resistor transmits the third average signal to an eighth terminal of the switch when the high-side switch is turned on to provide the sampling signal

The load adjusting circuit has the advantages of simple implementation, convenience in integration and lower production cost.

Drawings

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

Detailed Description

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

As shown in fig. 1, the present invention provides a zero point detection circuit, which is characterized by comprising a load power supply circuit, a voltage dividing resistor, a switching tube, a zero point detection circuit, and a load adjustment compensation circuit, wherein the load power supply circuit comprises a load, a diode, and an inductor, the load, the diode, and the inductor are connected in series to form a loop circuit, one end of the load power supply circuit is connected to a working voltage input end, and the load adjustment compensation circuit comprises: and the voltage buffer is coupled between the filtering output end of the third filtering circuit and the seventh end of the switch, receives the third average signal, increases the current driving capability of the third average signal, outputs the third average signal with the increased current driving capability to the seventh end of the switch, connects the other end of the load power circuit with the first end of the switch tube and the first end of the divider resistor, connects the second end of the divider resistor and the second end of the switch tube to the ground, controls the load voltage by using the switch tube, connects the voltage dividing end of the divider resistor with the signal input end of the zero-crossing detection circuit, and obtains the current zero-crossing point of the diode by using the zero-crossing detection circuit.

In a further aspect, the divider resistor transmits the third average signal to an eighth terminal of the switch when the high-side switch is turned on to provide the sampling signal

The load adjusting circuit has the advantages of simple implementation, convenience in integration and lower production cost.

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.