Auxiliary power supply EMC universal jittering frequency circuit

Abstract

The utility model discloses an auxiliary power supply EMC universal jittering frequency circuit, comprising a frequency selection module used for determining the frequency of an output sine wave; the in-phase amplification module is electrically connected to the frequency selection module and is used for starting oscillation of the circuit; the normal-phase gain network is electrically connected with the in-phase amplification module and used for being matched with the in-phase amplification module to adjust and self-stabilize the signals; the third capacitor C3 is electrically connected to the output side of the in-phase amplification module and used for removing the direct-current component and leaving an alternating-current component; one end of the output voltage-dividing module is electrically connected to the capacitor C3, the other end of the output voltage-dividing module is grounded, and a voltage-dividing wiring end is used for being connected with the analog control IC and the oscillator at the same time. According to the invention, the EMC radiation interference of the auxiliary power supply of a power supply product of a company can be optimized with relatively low cost.

Description

Technical Field

[0001] The present application relates to the technical field of radiation control of power supply products, and in particular to a universal frequency-jittering circuit for auxiliary power supply EMC. Background Art

[0002] In order to further adapt to market competition, power supply products are gradually tending towards multi-circuit reuse. Among them, the auxiliary power supply circuit of photovoltaic products is particularly prominent. The development trend is to adapt to the high voltage and low-cost multi-circuit reuse of a wide range of power supplies. This leads to the existence of large EMC radiation interference in the separate auxiliary power supply itself, which poses a great challenge to the product EMC radiation rectification requirements.

[0003] The frequency jittering technology used in the market to optimize the EMC radiation interference of the auxiliary power supply is usually adopted from analog control ICs with frequency jittering function. However:

[0004] An analog control IC with a frequency jittering function is used. Because the starting voltage and working mode (intermittent, continuous) of the company's different power supply products are different, it is difficult to make the auxiliary power supply compatible with all products by replacing the analog control IC; and the price of analog control IC with frequency jittering function is generally more expensive, which is unacceptable for the company's low-cost power supply products. Utility Model Content

[0005] In order to optimize the auxiliary power supply EMC radiation interference of the company's power supply products at a lower cost, the present application provides an auxiliary power supply EMC universal frequency jitter circuit.

[0006] The present application provides an auxiliary power supply EMC universal frequency jitter circuit, which adopts the following technical solution:

[0007] An auxiliary power supply EMC universal frequency jitter circuit, comprising:

[0008] Frequency selection module, which is used to determine the frequency of the output sine wave;

[0009] A common-phase amplifier module, which is electrically connected to the frequency selection module and is used for circuit oscillation start-up;

[0010] A positive phase gain network is formed, which is electrically connected to the in-phase amplifier module and is used to cooperate with the in-phase amplifier module to adjust the signal for self-stabilization;

[0011] Capacitor C3, which is electrically connected to the output side of the in-phase amplifier module and is used to remove the DC component and leave the AC component; and

[0012] The output voltage divider module has one end electrically connected to capacitor C3 and the other end grounded. The voltage divider terminal is used to simultaneously connect the analog control IC and the oscillator.

[0013] Optionally, the frequency selection module includes:

[0014] Resistor 2 R2, one end of which is connected to GND;

[0015] Capacitor 1 C1, which is connected in parallel to resistor 2 R2;

[0016] A capacitor C2, one end of which is electrically connected to a connection point between the resistor R2 and the capacitor C1; and

[0017] A resistor R3, one end of which is electrically connected to the other end of the capacitor C2, and the other end of which is electrically connected to the capacitor C3;

[0018] The connection point between the resistor 2 R2 and the capacitor 1 C1 is also electrically connected to the input and output sides of the in-phase amplifier module.

[0019] Optionally, the in-phase amplification module includes:

[0020] A common-phase amplifier A, whose common-phase input terminal is connected to the connection point of the resistor 2 R2 and the capacitor 1 C1, and whose output terminal is connected to the connection point of the capacitor 3 C3 and the resistor 3 R3;

[0021] A resistor six R6, one end of which is connected to GND; and

[0022] A resistor R7, one end of which is electrically connected to the resistor R6, and the other end of which is connected to the output end of the common-mode amplifier A;

[0023] Among them, the reverse input terminal of the common-phase amplifier A is connected to the connection point of resistor six R6 and resistor seven R7; the non-phase input terminal of the common-phase amplifier A is also connected to the positive electrode of the DC power supply, and the negative electrode of the DC power supply is connected to GND.

[0024] Optionally, the positive phase gain network comprises:

[0025] Zener diode ZD1;

[0026] A second Zener diode ZD2, which is connected in reverse parallel to the first Zener diode ZD1; and

[0027] A resistor R8, one end of which is connected to the connection point of the Zener diode ZD1 and the Zener diode ZD2, and the other end of which is used to connect the connection point of the resistor R7 and the inverting input terminal of the common-mode amplifier A;

[0028] The other connection point of the Zener diode 1 ZD1 and the Zener diode 2 ZD2 connected in reverse parallel is used to connect the connection point of the resistor 7 R7 and the output end of the in-phase amplifier A.

[0029] Optionally, the output voltage divider module includes a resistor R4 and a resistor R5 connected in series, wherein one end of the resistor R4 and the resistor R5 connected in series is connected to GND, and the other end is connected to capacitor C3;

[0030] The connection point between the resistor four R4 and the resistor five R5 is used to connect the analog control IC and the oscillator.

[0031] Optionally, a capacitor C4 is also included, wherein the capacitor C4 is connected in series to the resistor R6 and the other end is connected to GND.

[0032] To summarize, the present application includes at least one of the following beneficial technical effects: the present application can use a frequency selection module to determine the frequency of the output sine wave, relatively easily match the electrical component parameters of the frequency selection module, and quickly adjust the frequency of the output sine wave; and then use the positive phase gain network composition to cooperate with the in-phase amplifier module to adjust the signal for self-stabilization; therefore, the present application can match low-cost analog ICs, freely adjust the jitter range and jitter speed according to the EMC situation, and uniformly optimize and rectify the auxiliary power supply EMC radiation interference of the company's power supply products. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the circuit structure of this application. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1 This application is described in further detail.

[0035] The embodiment of the present application discloses a universal frequency jittering circuit for auxiliary power supply EMC.

[0036] Reference Figure 1 , the auxiliary power supply EMC general frequency jitter circuit includes:

[0037] Frequency selection module, which is used to determine the frequency of the output sine wave;

[0038] A common-phase amplifier module, which is electrically connected to the frequency selection module and is used for circuit oscillation start-up;

[0039] A positive phase gain network is formed, which is electrically connected to the in-phase amplifier module and is used to cooperate with the in-phase amplifier module to adjust the signal for self-stabilization;

[0040] Capacitor C3, which is electrically connected to the output side of the in-phase amplifier module and is used to remove the DC component and leave the AC component; and

[0041] The output voltage divider module has one end electrically connected to capacitor C3 and the other end grounded. The voltage divider terminal is used to simultaneously connect the analog control IC and the oscillator.

[0042] According to the above settings, the present application can use a frequency selection module to determine the frequency of the output sine wave, and relatively easily match the electrical component parameters of the frequency selection module to quickly adjust the frequency of the output sine wave; then use the positive phase gain network composition to cooperate with the in-phase amplifier module to adjust the signal for self-stabilization; therefore, the present application can match low-cost analog ICs, freely adjust the jitter range and jitter speed according to the EMC situation, and uniformly optimize and rectify the auxiliary power supply EMC radiation interference of the company's power supply products.

[0043] The above frequency selection module comprises:

[0044] Resistor 2 R2, one end of which is connected to GND;

[0045] Capacitor 1 C1, which is connected in parallel to resistor 2 R2;

[0046] A capacitor C2, one end of which is electrically connected to a connection point between the resistor R2 and the capacitor C1; and

[0047] A resistor R3, one end of which is electrically connected to the other end of the capacitor C2, and the other end of which is electrically connected to the capacitor C3;

[0048] The connection point between the resistor 2 R2 and the capacitor 1 C1 is also electrically connected to the input and output sides of the in-phase amplifier module.

[0049] The above resistor 2 R2, capacitor 1 C1, capacitor 2 C2 and resistor 3 R3 form a series-parallel feedback network, and the feedback coefficient of the network is a function of the frequency:

[0050]

[0051] Based on the above, it can be seen that matching the resistance and capacitance values ​​can quickly adjust the frequency of the output sine wave.

[0052] The above-mentioned common-phase amplifier module includes:

[0053] A common-phase amplifier A, whose common-phase input terminal is connected to the connection point of the resistor 2 R2 and the capacitor 1 C1, and whose output terminal is connected to the connection point of the capacitor 3 C3 and the resistor 3 R3;

[0054] A resistor six R6, one end of which is connected to GND; and

[0055] A resistor R7, one end of which is electrically connected to the resistor R6, and the other end of which is connected to the output end of the common-mode amplifier A;

[0056] Among them, the reverse input terminal of the common-phase amplifier A is connected to the connection point of the resistor six R6 and the resistor seven R7; the non-phase input terminal of the common-phase amplifier A is also connected to the positive electrode of the DC power supply, and the negative electrode of the DC power supply is connected to GND.

[0057] The module's in-phase amplification ratio is determined by resistor seven R7 and resistor six R6, so the amplification factor of the circuit is as follows: When the amplification factor is greater than 3, the positive feedback branch is dominant, and the circuit is not stable at the beginning of oscillation, and the oscillation will continue to increase. That is, resistor six R6 and resistor seven R7 cooperate with the in-phase amplifier A to form a positive gain network to ensure that the overall gain is greater than 1, which plays the role of oscillation.

[0058] In one embodiment of the present application, a positive phase gain network is formed, which includes:

[0059] Zener diode ZD1;

[0060] A second Zener diode ZD2, which is connected in reverse parallel to the first Zener diode ZD1; and

[0061] A resistor R8, one end of which is connected to the connection point of the Zener diode ZD1 and the Zener diode ZD2, and the other end of which is used to connect the connection point of the resistor R7 and the inverting input terminal of the common-phase amplifier A;

[0062] Among them, another connection point of the reverse parallel connection of the Zener diode 1 ZD1 and the Zener diode 2 ZD2 is used to connect the connection point of the resistor 7 R7 and the output end of the in-phase amplifier A.

[0063] When the output voltage increases due to oscillation, it exceeds the voltage drop of Zener diode 1 ZD1 and Zener diode 2 ZD2. At this time, resistor 8 R8 and Zener diode 1 ZD1, Zener diode 2 ZD2 and resistor 7 R7 are connected in parallel, so the amplification factor of the circuit can be approximated as: At this time, the amplification factor is less than 3, the negative feedback branch is dominant, and the circuit oscillation tends to be stable; that is, resistor six R6 and resistor seven R7 and resistor eight R8, Zener diode ZD1 and Zener diode ZD2 together form a positive phase gain network to ensure that the overall gain is less than 1, which plays a role in regulating self-stabilization.

[0064] In one embodiment of the present application, the output voltage divider module includes a resistor R4 and a resistor R5 connected in series, wherein one end of the resistor R4 and the resistor R5 connected in series is connected to GND, and the other end is connected to capacitor C3;

[0065] The connection point of resistor four R4 and resistor five R5 is used to connect the analog control IC and the oscillator.

[0066] The resistor four R4 and the resistor five R5 are an output voltage divider network, which can quickly adjust the voltage divider amplitude of the output voltage.

[0067] In one embodiment of the present application, a capacitor C4 is further included. The capacitor C4 is connected in series to the resistor R6 and the other end of the capacitor C4 is connected to GND.

[0068] Capacitor four C4 is a DC blocking capacitor, which converts the DC input model into a voltage follower, so that the gain link only acts on AC signals.

[0069] In summary, this application has the following advantages:

[0070] 1. It can match low-cost analog IC, and the cost of use is relatively lower;

[0071] 2. High flexibility (dithering amplitude and dithering speed are adjustable);

[0072] 3. High compatibility (adaptable to AD-DC, DC-DC auxiliary power supply;

[0073] 4. Wide adjustment range and good EMC effect.

[0074] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A universal frequency-jittering circuit for auxiliary power supply EMC, characterized in that: include: Frequency selection module, which is used to determine the frequency of the output sine wave; A common-phase amplifier module, which is electrically connected to the frequency selection module and is used for circuit oscillation start-up; A positive phase gain network is formed, which is electrically connected to the in-phase amplifier module and is used to cooperate with the in-phase amplifier module to adjust the signal for self-stabilization; Capacitor C3, which is electrically connected to the output side of the in-phase amplifier module and is used to remove the DC component and leave the AC component; and The output voltage divider module has one end electrically connected to capacitor C3 and the other end grounded. The voltage divider terminal is used to simultaneously connect the analog control IC and the oscillator.

2. The auxiliary power supply EMC universal frequency jitter circuit according to claim 1, characterized in that: The frequency selection module comprises: Resistor 2 R2, one end of which is connected to GND; Capacitor 1 C1, which is connected in parallel to resistor 2 R2; A capacitor C2, one end of which is electrically connected to a connection point between the resistor R2 and the capacitor C1; and A resistor R3, one end of which is electrically connected to the other end of the capacitor C2, and the other end of which is electrically connected to the capacitor C3; The connection point between the resistor 2 R2 and the capacitor 1 C1 is also electrically connected to the input and output sides of the in-phase amplifier module.

3. The auxiliary power supply EMC universal frequency jitter circuit according to claim 2, characterized in that: The in-phase amplification module comprises: A common-phase amplifier A, whose common-phase input terminal is connected to the connection point of the resistor 2 R2 and the capacitor 1 C1, and whose output terminal is connected to the connection point of the capacitor 3 C3 and the resistor 3 R3; A resistor six R6, one end of which is connected to GND; and A resistor R7, one end of which is electrically connected to the resistor R6, and the other end of which is connected to the output end of the common-mode amplifier A; Among them, the reverse input terminal of the common-phase amplifier A is connected to the connection point of resistor six R6 and resistor seven R7; the non-phase input terminal of the common-phase amplifier A is also connected to the positive electrode of the DC power supply, and the negative electrode of the DC power supply is connected to GND.

4. The auxiliary power supply EMC universal frequency jitter circuit according to claim 3, characterized in that: The positive phase gain network is composed of: Zener diode ZD1; A second Zener diode ZD2, which is connected in reverse parallel to the first Zener diode ZD1; and A resistor R8, one end of which is connected to the connection point of the Zener diode ZD1 and the Zener diode ZD2, and the other end of which is used to connect the connection point of the resistor R7 and the inverting input terminal of the common-phase amplifier A; Among them, another connection point of the Zener diode 1 ZD1 and the Zener diode 2 ZD2 which are connected in reverse parallel is used to connect the connection point of the resistor 7 R7 and the output end of the in-phase amplifier A.

5. The auxiliary power supply EMC universal frequency jitter circuit according to claim 4, characterized in that: The output voltage divider module includes a resistor R4 and a resistor R5 connected in series, wherein one end of the resistor R4 and the resistor R5 connected in series is connected to GND, and the other end is connected to capacitor C3; The connection point between the resistor four R4 and the resistor five R5 is used to connect the analog control IC and the oscillator.

6. The auxiliary power supply EMC universal frequency jitter circuit according to claim 3, characterized in that: The device also includes a capacitor C4, which is connected in series to the resistor R6 and has the other end connected to GND.

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