阅读说明：本技术 一种两级联变换器控制电路和直流通信电源 (Two-stage converter control circuit and direct current communication power supply ) 是由 尹德材 刘孝臣 于 2019-09-20 设计创作，主要内容包括：两级联变换器控制电路和直流通信电源,包括：非隔离变换器、隔离变换器、PWM发生器、非隔离变换器控制芯片以及采样电路；非隔离变换器的第一输出端与隔离变换器的第一输入端相连；非隔离变换器的第二输出端与隔离变换器的第二输入端相连；PWM发生器,用于输出第一时钟信号和第二时钟信号,第二时钟信号为第一时钟信号的二分频；采样电路用于采集隔离变换器的输出信号；隔离变换器用于获取第二时钟信号,将第二时钟信号作为隔离变换器的控制信号的触发信号；非隔离变换器控制芯片用于基于PWM发生器输出的第一时钟信号向非隔离变换器输出控制信号,以控制非隔离变换器和隔离变换器同步工作,使得非隔离变换器可以应用在直流通信电源中。(Two cascade connection converter control circuit and direct current communication power supply include: the device comprises a non-isolated converter, an isolated converter, a PWM generator, a non-isolated converter control chip and a sampling circuit; the first output end of the non-isolated converter is connected with the first input end of the isolated converter; the second output end of the non-isolated converter is connected with the second input end of the isolated converter; the PWM generator is used for outputting a first clock signal and a second clock signal, and the second clock signal is the halving frequency of the first clock signal; the sampling circuit is used for collecting the output signal of the isolated converter; the isolation converter is used for acquiring a second clock signal and taking the second clock signal as a trigger signal of a control signal of the isolation converter; the non-isolated converter control chip is used for outputting a control signal to the non-isolated converter based on the first clock signal output by the PWM generator so as to control the non-isolated converter and the isolated converter to work synchronously, so that the non-isolated converter can be applied to a direct-current communication power supply.)

1. A two-stage cascaded converter control circuit, comprising:

the device comprises a non-isolated converter, an isolated converter, a PWM generator, a non-isolated converter control chip and a sampling circuit;

the first output end of the non-isolated converter is connected with the first input end of the isolated converter;

the second output end of the non-isolated converter is connected with the second input end of the isolated converter;

the PWM generator is used for outputting a first clock signal and a second clock signal, and the second clock signal is the frequency division of two of the first clock signal;

the sampling circuit is used for acquiring an output signal of the isolation converter;

the isolation converter is used for acquiring the second clock signal and taking the second clock signal as a driving signal of the isolation converter;

the non-isolated converter control chip is used for outputting a control signal to the non-isolated converter based on a first clock signal output by the PWM generator so as to control the non-isolated converter and the isolated converter to work synchronously, and adjusting the control signal output to the non-isolated converter based on the output signal of the isolated converter collected by the sampling circuit so as to realize closed-loop control of the output signal of the isolated converter.

2. The two-cascaded converter control circuit of claim 1, comprising:

the second clock signal includes a CLK2-A signal and a CLK2-B signal, where the CLK2-A signal and the CLK2-B signal are a complementary pair of PWM signals having a 50% duty cycle.

3. A two-cascaded converter control circuit according to claim 1, wherein the non-isolated converter is a Buck-type non-isolated converter, a Boost-type non-isolated converter, a Buck-Boost-type non-isolated converter or a Cuk-type non-isolated converter.

4. A two-cascaded converter control circuit according to claim 1, wherein the isolated converter is a complementary dual 50% fixed duty cycle isolated converter.

5. The two-cascaded converter control circuit according to claim 4, wherein the isolated converter is a push-pull isolated converter, a half-bridge isolated converter, a full-bridge isolated converter, a forward isolated converter, or a flyback isolated converter.

6. A two-cascaded converter control circuit according to claim 1,

the PWM generator is a PWM circuit realized based on a microcontroller or an analog circuit.

7. A two-cascaded converter control circuit according to claim 3, wherein when the non-isolated converter is a Buck-Boost type non-isolated converter, the non-isolated converter comprises:

the circuit comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first inductor and a first capacitor;

the first end of the first switching tube is connected with the positive output end of an external power supply, the second end of the first switching tube is connected with the first end of the first inductor, and the first end of the first switching tube is used as the first input end of the non-isolated converter;

the first end of the second switching tube is connected with the second end of the first switching tube, the second end of the second switching tube is connected with the negative output end of the external power supply, and the second end of the second switching tube is used as the second input end of the non-isolated converter;

the first end of the third switching tube is connected with the second end of the first inductor, and the second end of the third switching tube is connected with the negative output end of the external power supply;

a first end of the fourth switching tube is connected with a first end of the first capacitor, a second end of the fourth switching tube is connected with a second end of the first inductor, and a first end of the fourth switching tube is used as a first output end of the non-isolated converter;

and the second end of the first capacitor is connected with the second end of the third switching tube, and the second end of the first capacitor is used as the second output end of the non-isolated converter.

8. The two-cascaded converter control circuit of claim 5, wherein when the isolated converter is a push-pull isolated converter, the isolated converter comprises:

the power supply comprises a fifth switching tube, a sixth switching tube, a seventh switching tube, an eighth switching tube, a second capacitor, a first isolation transformer and a second isolation transformer;

the second end of the main winding of the first isolation transformer is connected with the first end of the main winding of the second isolation transformer, and the second end of the main winding of the first isolation transformer is used as the first input end of the isolation converter; the second end of the secondary winding of the first isolation transformer is connected with the first end of the secondary winding of the second isolation transformer, and the second end of the secondary winding of the first isolation transformer is used as the first output end of the isolation converter;

the first end of the fifth switching tube is connected with the first end of the main winding of the first isolation transformer, and the second end of the fifth switching tube is connected with the second end of the sixth switching tube;

a first end of the sixth switching tube is connected with a second end of the main winding of the second isolation transformer, and a second end of the sixth switching tube is used as a second input end of the isolation converter;

a first end of the seventh switching tube is connected with a first end of the secondary winding of the first isolation transformer, and a second end of the seventh switching tube is connected with a second end of the eighth switching tube;

and a first end of the eighth switching tube is connected with a second end of the secondary winding of the second isolation transformer, and a second end of the eighth switching tube is used as a second output end of the isolation converter.

9. A two-stage converter control circuit according to any of claims 7 or 8, wherein each of the switching transistors is a MOS transistor or a triode.

10. A dc communication power supply comprising the two-stage cascade converter control circuit according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of integrated circuits, in particular to a two-stage converter control circuit and a direct-current communication power supply which realize isolation through a non-isolated power supply control chip.

Background

Disclosure of Invention

In view of this, the embodiment of the present invention provides a two-stage converter control circuit and a dc communication power supply, so as to implement application of a non-isolated control chip in the dc communication power supply.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

a two-cascade converter control circuit comprising:

the device comprises a non-isolated converter, an isolated converter, a PWM generator, a non-isolated converter control chip and a sampling circuit;

the first output end of the non-isolated converter is connected with the first input end of the isolated converter;

the second output end of the non-isolated converter is connected with the second input end of the isolated converter;

the PWM generator is used for outputting a first clock signal and a second clock signal, and the second clock signal is the frequency division of two of the first clock signal;

the sampling circuit is used for acquiring an output signal of the isolation converter;

the isolation converter is used for acquiring the second clock signal and taking the second clock signal as a driving signal of the isolation converter;

the non-isolated converter control chip is used for outputting a control signal to the non-isolated converter based on a first clock signal output by the PWM generator so as to control the non-isolated converter and the isolated converter to work synchronously, and adjusting the control signal output to the non-isolated converter based on the output signal of the isolated converter collected by the sampling circuit so as to realize closed-loop control of the output signal of the isolated converter.

Optionally, the two cascaded converter control circuits include:

the second clock signal includes a CLK2-A signal and a CLK2-B signal, where the CLK2-A signal and the CLK2-B signal are a complementary pair of PWM signals having a 50% duty cycle.

Optionally, in the two cascade converter control circuits, the non-isolated converter is a Buck type non-isolated converter, a Boost type non-isolated converter, a Buck-Boost type non-isolated converter or a Cuk type non-isolated converter.

Optionally, in the control circuit of the two cascaded converters, the isolation converter is a complementary dual-50% isolation converter with a fixed duty ratio.

Optionally, in the control circuit of the two cascaded converters, the isolation converter is a push-pull isolation converter, a half-bridge isolation converter, a full-bridge isolation converter, a forward isolation converter, or a flyback isolation converter.

Optionally, in the control circuit of the two cascaded converters, the PWM generator is a PWM circuit implemented based on a microcontroller or an analog circuit.

Optionally, in the two cascaded converter control circuits, when the non-isolated converter is a Buck-Boost type non-isolated converter, the non-isolated converter includes:

the circuit comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first inductor and a first capacitor;

the first end of the first switching tube is connected with the positive output end of an external power supply, the second end of the first switching tube is connected with the first end of the first inductor, and the first end of the first switching tube is used as the first input end of the non-isolated converter;

the first end of the second switching tube is connected with the second end of the first switching tube, the second end of the second switching tube is connected with the negative output end of the external power supply, and the second end of the second switching tube is used as the second input end of the non-isolated converter;

the first end of the third switching tube is connected with the second end of the first inductor, and the second end of the third switching tube is connected with the negative output end of the external power supply;

a first end of the fourth switching tube is connected with a first end of the first capacitor, a second end of the fourth switching tube is connected with a second end of the first inductor, and a first end of the fourth switching tube is used as a first output end of the non-isolated converter;

and the second end of the first capacitor is connected with the second end of the third switching tube, and the second end of the first capacitor is used as the second output end of the non-isolated converter.

Optionally, in the two cascaded converter control circuits, when the isolation converter is a push-pull isolation converter, the isolation converter includes:

the power supply comprises a fifth switching tube, a sixth switching tube, a seventh switching tube, an eighth switching tube, a second capacitor, a first isolation transformer and a second isolation transformer;

the second end of the main winding of the first isolation transformer is connected with the first end of the main winding of the second isolation transformer, and the second end of the main winding of the first isolation transformer is used as the first input end of the isolation converter; the second end of the secondary winding of the first isolation transformer is connected with the first end of the secondary winding of the second isolation transformer, and the second end of the secondary winding of the first isolation transformer is used as the first output end of the isolation converter;

the first end of the fifth switching tube is connected with the first end of the main winding of the first isolation transformer, and the second end of the fifth switching tube is connected with the second end of the sixth switching tube;

a first end of the sixth switching tube is connected with a second end of the main winding of the second isolation transformer, and a second end of the sixth switching tube is used as a second input end of the isolation converter;

a first end of the seventh switching tube is connected with a first end of the secondary winding of the first isolation transformer, and a second end of the seventh switching tube is connected with a second end of the eighth switching tube;

and a first end of the eighth switching tube is connected with a second end of the secondary winding of the second isolation transformer, and a second end of the eighth switching tube is used as a second output end of the isolation converter.

Optionally, in the control circuit of the two cascaded converters, each of the switching tubes is an MOS tube or an audion.

A direct current communication power supply comprises the two-stage cascade converter control circuit.

Based on the technical scheme, the technical scheme provided by the embodiment of the invention comprises the following steps: the device comprises a non-isolated converter, an isolated converter, a PWM generator, a non-isolated converter control chip and a sampling circuit; the PWM generator is used for outputting a first clock signal and a second clock signal, and the second clock signal is the frequency division of two of the first clock signal; the sampling circuit is used for acquiring an output signal of the isolation converter; the isolation converter is used for acquiring the second clock signal and taking the second clock signal as a driving signal of the isolation converter; the non-isolated converter control chip is used for outputting a control signal to the non-isolated converter based on a first clock signal output by the PWM generator so as to control the non-isolated converter and the isolated converter to work synchronously, and adjusting the control signal output to the non-isolated converter based on the output signal of the isolated converter collected by the sampling circuit so as to realize closed-loop control of the output signal of the isolated converter. According to the scheme, the first clock signal is output to the non-isolated converter, the second clock signal is output to the isolated converter, so that the working frequencies of the non-isolated converter and the isolated converter are consistent, the non-isolated converter can be applied to a direct-current communication power supply, and the performance of the direct-current communication power supply is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a control circuit of a two-cascade converter disclosed in an embodiment of the present application;

fig. 2 is a schematic diagram illustrating a logical relationship between a first clock signal in a control circuit of a two-cascaded converter and a control signal of a control chip of a non-isolated converter according to an embodiment of the present application;

FIG. 3 is a diagram illustrating a comparison between a second clock signal and the first clock signal according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a control circuit of a two-cascade converter according to another embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

For example, some excellent Buck-Boost non-isolated control chips exist in the market at present, and the Buck-Boost non-isolated control chips have wide input voltage range and high efficiency; however, the existing bus power supply needs the original secondary side isolation processing, so that the non-isolated Buck-Boost non-isolation control chips cannot be used in the direct-current communication power supply at present, and the performance of the direct-current communication power supply is limited.