TWI759233B - Composite control circuit - Google Patents

Abstract

A composite control circuit includes an input terminal, a light-load signal processing circuit, a slow response circuit and a fast response circuit. The composite control circuit is mainly used as an additional circuit of a working control chip, so that although the working control chip only has a single overcurrent protection level, it can generate fast and slow speed, high and low level current protection and light load signals through the composite control circuit Stable composite function control to meet the complex and compatibility requirements of today's power supply environment.

Description

Composite control circuit

The present invention relates to an additional circuit used with a work control chip, in particular to a composite control circuit which enables a work control chip with only a single overcurrent protection level originally to have multiple response modes.

In order to ensure stable control of the power conversion circuit, a work control chip currently used to control the power conversion circuit generally has an overcurrent protection mechanism, and the operation of the power conversion circuit is ensured through the overcurrent protection mechanism. However, the overcurrent protection mechanism only decides whether to activate the protection based on a single judgment level, which cannot meet current application requirements or compatibility requirements in today's increasingly complex working environment of power conversion circuits.

In addition, some work control chips now have an energy-saving working mode, and whether the power conversion circuit works in the energy-saving working mode is determined through an energy-saving judgment level. However, when the power conversion circuit is in a light load state, the electrical signal fed back by the work control chip is unstable, so that the work control chip cannot accurately control the power conversion circuit.

The main purpose of the present invention is to solve the problem that the conventional work control chip only uses a single current protection level to determine whether to perform protection, which no longer meets the complex and compatibility requirements of today's power supply application environment.

Another object of the present invention is to solve the problem that the conventional work control chip with energy-saving control mode cannot obtain a stable feedback electrical signal when the controlled circuit is under light load operation, resulting in the problem that the work control chip cannot stably control the controlled circuit.

In order to achieve the above object, the present invention provides a composite control circuit, which is connected to a current detection port of a work control chip, the work control chip compares a first electrical signal received by the current detection port at an overcurrent protection level, and the composite control circuit The control circuit includes an input terminal, a light-load signal processing circuit, a slow response circuit and a fast response circuit. The input terminal is connected to a detection point to obtain a second electrical signal, the light-load signal processing circuit is connected to the input terminal and receives the second electrical signal, and the light-load signal processing circuit outputs a third electrical signal based on a signal processing mechanism , the signal processing mechanism includes two signal transition conditions, and the potential of the third electrical signal is determined based on the second electrical signal and the two signal transition conditions. The slow response circuit receives the second electrical signal and the third electrical signal from the input terminal and the light-load signal processing circuit, and the slow response circuit uses the second electrical signal and the third electrical signal to store energy, When the energy storage of the slow response circuit reaches a first response condition, it will provide the current detection port with the first electrical signal whose potential is consistent with the overcurrent protection level. The fast response circuit receives the second electrical signal and the third electrical signal from the input terminal and the light-load signal processing circuit, and the fast response circuit reaches a second electrical potential when the potential of the second electrical signal or the third electrical signal reaches a second When responding to conditions, the first electrical signal whose potential is consistent with the overcurrent protection level is quickly provided to the current detection port.

In one embodiment, the composite control circuit includes a first diode disposed at the input end and the slow response circuit and the fast response circuit.

In one embodiment, the composite control circuit includes a first capacitor connected to the slow response circuit, the fast response circuit and the current detection port.

In one embodiment, the slow response circuit includes a second capacitor and a first resistor forming a first node with the second capacitor, the first node connecting the first diode and the light-load signal processing circuit, The first node receives the second electrical signal transmitted by the first diode and the third electrical signal output by the light-load signal processing circuit, the negative electrode of the second capacitor is grounded, and the first resistor is not connected to the second electrical signal One end of the two capacitors is connected to the current detection port.

In one embodiment, the fast response circuit includes a second resistor, a third resistor connected in series with the second resistor and forming a second node, and a second diode connected to the third resistor, the second resistor The positive pole of the diode is connected to the second node, the negative pole is connected to the current detection port, the second resistor is connected to the first diode and the light-load signal processing circuit, and the second resistor receives the transmission from the first diode The second electrical signal and the third electrical signal output by the light-load signal processing circuit.

In one embodiment, the light-load signal processing circuit includes a fourth resistor, a third capacitor connected in series with the fourth resistor and forming a third node, a comparator, a comparator, and the slow response circuit. With the third diode of the fast response circuit, a fourth diode connecting the third diode and the comparator, and a fifth resistor connecting the fourth diode and the third node, the The comparator has a positive phase input terminal connected to the third node, a negative phase input terminal connected to a reference voltage source, and an output terminal forming a fourth node with the third diode and the fourth diode , the anode of the third diode is connected to the fourth node, and the anode of the fourth diode is connected to the fourth node.

In one embodiment, the light-load signal processing circuit includes a sixth resistor, a fourth capacitor connected in series with the sixth resistor and forming a fifth node, a voltage stabilizing transistor, a working voltage source, and a fourth capacitor connected to the sixth resistor. The working voltage source is connected to the seventh resistor of the voltage stabilizer triode, a metal-oxygen semi-field effect transistor, an eighth resistor connected to the voltage stabilizer triode, and the eighth resistor connected in series to form a sixth node. A ninth resistor, a fifth diode connected to the slow response circuit and the fast response circuit, a sixth diode connected to the fifth diode and forming a seventh node, and a sixth diode connected to the sixth diode A diode is connected in series with a tenth resistor of the fifth node, and an eleventh resistor connected to the operating voltage source and the seventh node. The gate of the MOSFET is connected to the sixth node, and the The drain electrode of the MOSFET is connected to the seventh node, the anode of the fifth diode is connected to the seventh node, the anode of the sixth diode is connected to the seventh node, and the voltage stabilizer triode is connected to the seventh node. The seventh resistor and the eighth resistor are connected to form an eighth node.

In one embodiment, the work control chip is an LLC circuit work control chip.

Through the aforementioned implementation of the present invention, compared with the conventional one, the composite control circuit of the present invention has the following characteristics: through the differences in the response time and triggering action level of the fast response circuit, the slow response circuit, and the triggering action level, the work control chip originally only has Some single trigger state can be derived from a variety of control types. In addition, the light-load signal processing circuit of the present invention processes the second electrical signal generated when the controlled circuit is in a light-load state, so as to avoid the oscillation of the second electrical signal when the light-load condition causes the working control chip to incorrectly control .

The detailed description and technical content of the present invention are described as follows in conjunction with the drawings:

Referring to FIG. 1 , the present invention provides a composite control circuit 10 , which is mainly used as an attached circuit for a work control chip 20 . The work control chip 20 can be an LLC circuit work control chip. The work control chip 20 has a The current detection port 21 connected to the control circuit 10, the operation control chip 20 compares a first electrical signal 30 received by the current detection port 21 with an overcurrent protection level, when the first electrical signal 30 level reaches the overcurrent When the protection level is specified, the work control chip 20 will control the controlled circuit 40 (eg LLC circuit) with a protection mechanism.

The composite control circuit 10 is connected to the current detection port 21 of the working control chip 20 . The composite control circuit 10 includes an input terminal 11 , a light-load signal processing circuit 12 , a slow response circuit 15 and a fast response circuit 16 . The input end 11 is connected to a detection point 41 to obtain a second electrical signal 31 . Please refer to FIG. 1 and FIG. 2 again. The light-load signal processing circuit 12 is connected to the input terminal 11 and receives the second electrical signal 31 . The second electrical signal 31 is transmitted to the subsequent stage circuit in a relatively stable form. The light-load signal processing circuit 12 outputs a third electrical signal 32 based on a signal processing mechanism. The signal processing mechanism includes two signal transition conditions. The level of the third electrical signal 32 is based on the second electrical signal 31 and the two signals. Transition conditions are determined. Specifically, the transition levels of the two signal transition conditions are different (50, 51 in FIG. 2 ), and the transition level of one of the two signal transition conditions is higher than the other one of the two signal transition conditions. First, the level of the second electrical signal 31 received by the light-load signal processing circuit 12 must meet one of the two signal transition conditions, and then the third electrical signal 32 can generate a transition. The third electrical signal 32 output by the light-load signal processing circuit 12 is like a general digital signal, and has only two types of high potential (1 in the digital signal) and low potential (0 in the digital signal). When the second electrical signal 31 received by the light-load signal processing circuit 12 is higher than or equal to the higher transition level of the two signal transition conditions, the third electrical signal 32 will be output at a high level. When the second electrical signal 31 subsequently received by the light-load signal processing circuit 12 is lower than or equal to the lower level of the transition state of the two signal transition conditions, the third electrical signal 32 will change from the original high level to the lower level. state is low potential. The third electrical signal 32 will not transition again until the second electrical signal 31 received by the light-load signal processing circuit 12 is again higher than or equal to the higher transition state level of the two signal transition conditions.

On the other hand, the slow response circuit 15 receives the second electrical signal 31 and the third electrical signal 32 from the input terminal 11 and the light-load signal processing circuit 12, and the slow response circuit 15 uses the second electrical signal 31 and the third electrical signal 32 store energy. When the slow response circuit 15 stores energy and reaches a first response condition, it will provide the current detection port 21 with the first electrical signal whose potential is consistent with the overcurrent protection level. 30 , the first reaction condition may be the energy storage potential of the slow reaction circuit 15 . It should be understood that the slow response circuit 15 of the present invention still provides the first electrical signal 30 to the current detection port 21 during the energy storage process, but at this time the potential of the first electrical signal 30 does not meet the overcurrent protection level.

In addition, the quick response circuit 16 receives the second electrical signal 31 and the third electrical signal 32 from the input terminal 11 and the light-load signal processing circuit 12 , and the quick response circuit 16 receives the second electrical signal 31 and the third electrical signal 32 When the potentials of the three electrical signals 32 are accumulated to reach a second response condition, the first electrical signal 30 whose potential is consistent with the overcurrent protection level is quickly provided to the current detection port 21 . Further, the difference between the fast response circuit 16 and the slow response circuit 15 is that the fast response circuit 16 directly reacts based on the potential accumulation of the second electrical signal 31 and the third electrical signal 32 . The fast reaction circuit 15 reacts with the stored potential. The above two reaction times and action levels are different, so that the original single trigger state of the work control chip 20 can be derived from a variety of control types.

Referring back to FIG. 1 , the composite control circuit 10 includes a first diode 17 disposed at the input end 11 and the slow response circuit 15 and the fast response circuit 16 . In one embodiment, the composite control circuit 10 includes a first capacitor 18 connected to the slow response circuit 15 , the fast response circuit 16 and the current detection port 21 .

Referring back to FIG. 1 and FIG. 3 , in one embodiment, the slow response circuit 15 includes a second capacitor 151 , and a first resistor 153 forming a first node 152 with the second capacitor 151 . The first The node 152 is connected to the first diode 17 and the light-load signal processing circuit 12 , and receives the second electrical signal 31 transmitted by the first diode 17 and the third electrical signal output by the light-load signal processing circuit 12 No. 32 , the negative electrode of the second capacitor 151 is grounded, and one end of the first resistor 153 not connected to the second capacitor 151 is connected to the current detection port 21 . On the other hand, the quick response circuit 16 includes a second resistor 161 , a third resistor 163 connected in series with the second resistor 161 and forming a second node 162 , and a second diode connected to the third resistor 163 body 164, the positive pole of the second diode 164 is connected to the second node 162, the negative pole is connected to the current detection port 21, the second resistor 161 is connected to the first diode 17 and the light-load signal processing circuit 12, and The second electrical signal 31 transmitted by the first diode 17 and the third electrical signal 32 output by the light-load signal processing circuit 12 are received.

Referring back to FIG. 1 and FIG. 4 , in one embodiment, the light-load signal processing circuit 12 includes a fourth resistor 121 , a third capacitor 123 connected in series with the fourth resistor 121 and forming a third node 122 , a Comparator 124, a third diode 125 connected to the comparator 124, the slow response circuit 15 and the fast response circuit 16, and a fourth diode connected to the third diode 125 and the comparator 124 body 126 and a fifth resistor 127 connecting the fourth diode 126 and the third node 122, the comparator 124 has a non-inverting input terminal 128 connected to the third node 122, and a reference voltage source 129 The negative-phase input terminal 130 of , and an output terminal 132 forming a fourth node 131 with the third diode 125 and the fourth diode 126, and the anode of the third diode 125 is connected to the fourth node 131 , the anode of the fourth diode 126 is connected to the fourth node 131 . In addition to the above, please refer to FIG. 5 , in another embodiment, the light-load signal processing circuit 12 includes a sixth resistor 133 , a fourth resistor 133 connected in series with the sixth resistor 133 and forming a fifth node 134 Capacitor 135, a voltage-stabilizing triode 136, a working voltage source 137, a seventh resistor 138 connecting the working voltage source 137 and the voltage-stabilizing triode 136, a metal-oxygen semi-field effect transistor 139, a connecting The eighth resistor 140 of the voltage stabilizing triode 136, a ninth resistor 142 connected in series with the eighth resistor 140 and forming a sixth node 141, and a fifth resistor 142 connecting the slow response circuit 15 and the fast response circuit 16 Diodes 143, a sixth diode 145 connected to the fifth diode 143 and forming a seventh node 144, and a tenth diode 145 connected in series with the sixth diode 145 and connected to the fifth node 134 Resistor 146, and an eleventh resistor 147 connecting the operating voltage source 137 and the seventh node 144, the gate of the MOSFET 139 is connected to the sixth node 141, the MOSFET 139 The drain is connected to the seventh node 144, the anode of the fifth diode 143 is connected to the seventh node 144, the anode of the sixth diode 145 is connected to the seventh node 144, and the voltage regulator triode 136 is connected to the seventh node 144. The seventh resistor 138 and the eighth resistor 140 are connected to form an eighth node 148 .

In summary, the above is only a preferred embodiment of the present invention, and should not limit the scope of implementation of the present invention, that is, all equivalent changes and modifications made according to the scope of the patent application of the present invention should still belong to the scope of the patent of the present invention.

10: Composite control circuit 11: Input terminal 12: Light load signal processing circuit 121: Fourth resistor 122: Third Node 123: The third capacitor 124: Comparator 125: Third diode 126: Fourth diode 127: Fifth resistor 128: Non-inverting input terminal 129: Reference voltage source 130: Negative phase input 131: Fourth Node 132: output terminal 133: Sixth resistor 134: Fifth Node 135: Fourth capacitor 136: voltage regulator triode 137: Working voltage source 138: Seventh resistor 139: Metal Oxygen Half Field Effect Transistor 140: Eighth resistor 141: Sixth Node 142: Ninth Resistor 143: Fifth Diode 144: Seventh Node 145: Sixth Diode 146: Tenth Resistance 147: Eleventh resistor 148: Eighth Node 15: Slow Response Circuit 151: Second capacitor 152: First Node 153: First resistor 16: Quick Response Circuit 161: Second resistor 162: Second Node 163: The third resistor 164: Second Diode 17: First diode 18: The first capacitor 20: Work Control Chip 21: Current detection port 30: First telecommunication signal 31: Second telecommunication signal 32: The third telecommunication signal 40: Controlled circuit 41: Detection point 50: Transition level 51: Transition level

FIG. 1 is a schematic diagram of the implementation of the composite control circuit of the present invention. FIG. 2 is a schematic diagram of the signal waveform of the second electrical signal generated when the controlled circuit is in a light-load state and subjected to signal processing by the light-load signal processing circuit of the present invention. FIG. 3 is a schematic circuit diagram of a slow response circuit and a fast response circuit according to an embodiment of the present invention. FIG. 4 is a schematic circuit diagram of a light-load signal processing circuit according to an embodiment of the present invention. FIG. 5 is a schematic circuit diagram of a light-load signal processing circuit according to another embodiment of the present invention.

10: Composite control circuit

11: Input terminal

12: Light load signal processing circuit

15: Slow Response Circuit

16: Quick Response Circuit

17: First diode

18: The first capacitor

20: Work Control Chip

21: Current detection port

30: First telecommunication signal

31: Second telecommunication signal

32: The third telecommunication signal

40: Controlled circuit

41: Detection point

Claims (9)

A composite control circuit is connected to a current detection port of a work control chip, the work control chip compares a first electrical signal received by the current detection port at an overcurrent protection level, and the composite control circuit comprises: an input terminal connected to a detection point to obtain a second electrical signal; A light-load signal processing circuit is connected to the input terminal and receives the second electrical signal. The light-load signal processing circuit outputs a third electrical signal based on a signal processing mechanism. The signal processing mechanism includes two signal transition conditions. The potential of the three electrical signals is determined based on the second electrical signal and the transition conditions of the two signals; A slow response circuit receives the second electrical signal and the third electrical signal from the input terminal and the light-load signal processing circuit, and the slow response circuit uses the second electrical signal and the third electrical signal to store energy , when the energy storage of the slow response circuit reaches a first response condition, it will provide the current detection port with the first electrical signal whose potential is consistent with the overcurrent protection level; and A quick response circuit receives the second electrical signal and the third electrical signal from the input end and the light-load signal processing circuit, and the quick response circuit accumulates the potentials of the second electrical signal and the third electrical signal to reach a In the second response condition, the first electrical signal whose potential is consistent with the overcurrent protection level is rapidly provided to the current detection port. The composite control circuit of claim 1, wherein the composite control circuit comprises a first diode connected to the input end and the slow response circuit and the fast response circuit. The composite control circuit of claim 2, wherein the composite control circuit comprises a first capacitor connected to the slow response circuit, the fast response circuit and the current detection port. The composite control circuit of claim 2 or 3, wherein the slow response circuit comprises a second capacitor and a first resistor forming a first node with the second capacitor, and the first node is connected to the first and second capacitors. The pole body and the light-load signal processing circuit, the first node receives the second electrical signal transmitted by the first diode and the third electrical signal output by the light-load signal processing circuit, the negative pole of the second capacitor grounded, and one end of the first resistor not connected to the second capacitor is connected to the current detection port. The composite control circuit of claim 4, wherein the fast response circuit comprises a second resistor, a third resistor connected in series with the second resistor and forming a second node, and a first resistor connected to the third resistor Two diodes, the positive pole of the second diode is connected to the second node, the negative pole is connected to the current detection port, the second resistor is connected to the first diode and the light-load signal processing circuit, and the second resistor accepts The second electrical signal transmitted by the first diode and the third electrical signal output by the light-load signal processing circuit. The composite control circuit of claim 2 or 3, wherein the fast response circuit comprises a second resistor, a third resistor connected in series with the second resistor and forming a second node, and a third resistor connected to the third resistor The second diode of the second diode, the positive pole of the second diode is connected to the second node, the negative pole is connected to the current detection port, the second resistor is connected to the first diode and the light-load signal processing circuit, the second The resistor receives the second electrical signal transmitted by the first diode and the third electrical signal output by the light-load signal processing circuit. The composite control circuit according to any one of claims 1 to 3, wherein the light-load signal processing circuit comprises a fourth resistor, a third capacitor connected in series with the fourth resistor and forming a third node, a comparison a third diode connected to the comparator, the slow response circuit and the fast response circuit, a fourth diode connected to the third diode and the comparator, and a fourth diode connected to the comparator The diode and the fifth resistor of the third node, the comparator has a positive phase input terminal connected to the third node, a negative phase input terminal connected to a reference voltage source, and a negative phase input terminal connected to the third diode and The fourth diode forms an output terminal of a fourth node, the positive electrode of the third diode is connected to the fourth node, and the positive electrode of the fourth diode is connected to the fourth node. The composite control circuit according to any one of claims 1 to 3, wherein the light-load signal processing circuit comprises a sixth resistor, a fourth capacitor connected in series with the sixth resistor and forming a fifth node, and a stable voltage triode, a working voltage source, a seventh resistor connecting the working voltage source and the stabilizing triode, a metal-oxygen semi-field effect transistor, an eighth resistor connecting the stabilizing triode, a A ninth resistor connected in series with the eighth resistor and forming a sixth node, a fifth diode connected to the slow response circuit and the fast response circuit, and a fifth diode connected to form a seventh A sixth diode of the node, a tenth resistor connected in series with the sixth diode and connected to the fifth node, and an eleventh resistor connected to the operating voltage source and the seventh node, the metal-oxygen half-field The gate of the effect transistor is connected to the sixth node, the drain of the MOSFET is connected to the seventh node, the anode of the fifth diode is connected to the seventh node, and the anode of the sixth diode is connected to the seventh node. The seventh node is connected, and the voltage stabilizing triode is connected with the seventh resistor and the eighth resistor to form an eighth node. The composite control circuit according to claim 1, wherein the work control chip is an LLC circuit work control chip.

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