Silicon controlled rectifier driving chip with alternating current zero-cross detection function and application circuit

Abstract

The utility model discloses a silicon controlled rectifier driving chip with an alternating current zero-cross detection function and an application circuit, and relates to the field of driving chips, and the chip comprises an electrostatic protection module, a zero-cross detection bias current module, a clamping circuit module, an under-voltage locking overvoltage protection module, a reference voltage module, a logic circuit module and an over-temperature protection module. The driving chip provided by the utility model not only can provide an alternating-current zero-crossing detection function, but also has the functions of over-temperature and over-voltage protection and the like, and meanwhile, the problems that the trigger current of the conventional bidirectional silicon controlled rectifier is increased at a low temperature, and the trigger current of the conventional bidirectional silicon controlled rectifier is too large, so that the driving current is insufficient under the condition that a singlechip is directly driven and controlled are solved. In order to solve the problem that the silicon controlled rectifier cannot be normally driven to be switched on, the single-chip microcomputer is utilized to amplify the too small driving current, so that the silicon controlled rectifier can be switched on only by a very small driving signal and time, and the problem that the silicon controlled rectifier cannot be controlled due to insufficient driving is avoided.

Description

Technical Field

[0001] The utility model relates to the field of driver chips, in particular to a thyristor driver chip with an AC zero-crossing detection function and an application circuit. Background Art

[0002] Zero-crossing detection uses electronic circuits to detect the zero-crossing point of the AC power supply. Specifically, it refers to the detection made by the system when the waveform in the AC system switches from the positive half-cycle to the negative half-cycle and passes through the zero position. It can be used for switching circuit or frequency detection. The existing AC zero-crossing detection solutions on the market use voltage-type detection solutions, and the detected AC zero-crossing point has a large accuracy deviation. At the same time, it can only perform zero-point detection and cannot process the zero-point signal and the drive signal generated by other circuits.

[0003] For example, Chinese patent CN210075194U discloses a thyristor drive circuit comprising a control signal input interface, an optocoupler, a drive unit, a constant current source, and a drive current output unit for connecting to the thyristor's gate. This circuit prevents the effects of thyristor gate voltage variations on the thyristor gate drive current and drive power. However, the circuitry implemented in this circuit is relatively complex, capable only of amplifying the drive signal. Furthermore, the circuit is complex, susceptible to external interference, has limited functionality, and is costly.

[0004] For example, Chinese patent CN204065223U discloses a zero-crossing detection circuit with a high-precision zero-crossing detector for detecting the zero-crossing point of an AC input signal. The circuit can be directly connected to both ends of a power module to obtain the zero-crossing signal. However, in practical applications, the entire circuit is constructed using discrete components. The entire circuit includes a power supply circuit, a zero-crossing signal shaping circuit, and a zero-crossing signal output circuit. After running these multiple circuits, the sampling accuracy of the zero-crossing signal is low, and the circuit's functions are relatively simple.

[0005] For example, Chinese patent CN218887183U discloses a plastic-encapsulated thyristor with built-in overtemperature protection. This device detects overtemperature through internal heat conduction and employs a positive temperature coefficient thermistor, providing overtemperature protection for both the thyristor itself and the circuitry using it, in addition to existing thyristors. However, this device only provides overtemperature protection for the thyristor itself and lacks sensor functionality, external communication, or notification of overtemperature conditions. It also fails to simultaneously detect zero-crossings, detect temperature, or provide driver amplification.

[0006] Currently, no effective solutions have been proposed for the problems in related technologies. Utility Model Content

[0007] In response to the problems in the related art, the present invention proposes a thyristor driver chip and an application circuit with an AC zero-crossing detection function to overcome the above technical problems existing in the existing related art.

[0008] To this end, the specific technical solutions adopted in this utility model are as follows:

[0009] In the first aspect, the utility model proposes a thyristor driver chip with AC zero-crossing detection function, including an electrostatic protection module, a zero-crossing detection bias current module, a clamping circuit module, an undervoltage lockout overvoltage protection module, a reference voltage module, a logic circuit module and an overtemperature protection module;

[0010] The electrostatic protection module is electrically connected to the zero-crossing detection bias current module, the zero-crossing detection bias current module is electrically connected to the clamping circuit module, the clamping circuit module is electrically connected to the undervoltage lockout overvoltage protection module, the undervoltage lockout overvoltage protection module is electrically connected to the reference voltage module, the reference voltage module is electrically connected to the logic circuit module, and the logic circuit module is electrically connected to the overtemperature protection module.

[0011] Furthermore, the zero-crossing detection bias current module and the clamping circuit module are composed of a resistor R1, an AND gate U1, a diode D1 and a diode D2;

[0012] One end of the resistor R1 is connected to the live wire L, the other end of the resistor R1 is respectively connected to the ZCD end, one end of the diode D1 and the first pin of the AND gate U1, the second pin of the AND gate U1 is connected to one end of the diode D2, the other end of the diode D2 is grounded, the other end of the diode D1 is connected to the undervoltage lockout overvoltage protection module and the reference voltage module and is grounded, and the third pin of the AND gate U1 is connected to the undervoltage lockout overvoltage protection module and the reference voltage module.

[0013] Furthermore, the undervoltage lockout overvoltage protection module and the reference voltage module are composed of a resistor R3, a resistor R4, an AND gate U2 and an operational amplifier OP1;

[0014] One end of the resistor R3 is connected to the other end of the diode D1, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and the first pin of the AND gate U2, the second pin of the AND gate U2 is connected to the neutral line N, the third pin of the AND gate U2 is respectively connected to the other end of the resistor R4 and the first pin of the operational amplifier OP1, the second pin of the operational amplifier OP1 is connected to the third pin of the AND gate U2, and the third and fourth pins of the operational amplifier OP1 are both connected to the logic circuit module.

[0015] Furthermore, the logic circuit module is composed of an AND gate U3, an operational amplifier OP2, and a field effect transistor Q1;

[0016] A first pin of the AND gate U3 is respectively connected to the ZERO terminal and the fourth pin of the operational amplifier OP1, a second pin of the AND gate U3 is connected to the EN terminal, a third pin of the AND gate U3 is connected to the first pin of the operational amplifier OP2, a second pin of the operational amplifier OP2 is connected to the over-temperature protection module, a third pin of the operational amplifier OP2 is connected to the third pin of the operational amplifier OP1, a fourth pin of the operational amplifier OP2 is connected to the first pin of the field effect transistor Q1, a second pin of the field effect transistor Q1 is connected to the GATE terminal, and a third pin of the field effect transistor Q1 is grounded.

[0017] Furthermore, the over-temperature protection module is composed of resistor R4, resistor R5 and AND gate U4;

[0018] The first pin of the AND gate U4 is connected to the second pin of the operational amplifier OP2, and the second pin of the AND gate U4 is connected to one end of the resistor R4 and one end of the resistor R5 respectively, and the other end of the resistor R4 is connected to V Z The other end of the resistor R5 is connected to the third pin of the AND gate U4 and is grounded.

[0019] Furthermore, when the live line voltage rises and passes through zero, the live line current is greater than the neutral line current, and when the live line voltage drops and passes through zero, the live line current is less than the neutral line current.

[0020] Secondly, the present invention also proposes the application of an application circuit of a thyristor driver chip with an AC zero-crossing detection function in AC zero-crossing detection.

[0021] The beneficial effects of the utility model are:

[0022] 1. The driver chip proposed in the present invention not only provides AC zero-crossing detection function, but also has over-temperature, over-voltage protection and other functions. At the same time, considering that the traditional bidirectional thyristor has a problem that the trigger current of the bidirectional thyristor becomes larger at low temperatures, and the trigger current itself is too large, resulting in insufficient driving current when the single-chip microcomputer directly drives and controls, and the thyristor cannot be driven to turn on normally. The single-chip microcomputer is used to amplify the excessively small driving current, so that the thyristor can be turned on with only a very small driving signal and time, avoiding the problem of insufficient driving and inability to control the thyristor.

[0023] 2. The AC zero-crossing detection function proposed by the present invention accurately detects the zero-crossing point of the AC power through an external resistor, and provides it to other circuits for AC zero-crossing judgment, which makes up for the zero-crossing detection circuit built by some components. The components themselves have certain accuracy problems, making the detection accuracy higher. At the same time, the proposed driver chip has an over-temperature protection function and needs to be as close to the heat source as possible. Once the temperature exceeds the protection point, even if there is still an external control signal given to the driver chip, the driver chip will not output a signal. Only when the temperature is lower than the reset temperature can the driver chip continue to restore the control function under the control of the external signal, thereby avoiding the situation where some traditional thyristors lose control once the junction temperature exceeds the tolerable junction temperature and remain in a working state, thereby reducing the risk of burning components and external circuits causing fires.

[0024] 3. The driver chip proposed in the present invention integrates the zero-crossing detection function, over-temperature protection function, amplification circuit, etc. to achieve high integration and miniaturization. When detecting the zero point of the AC power, it can be used for both the internal logic circuit and the external circuit. When driving the thyristor to work, it opens at the zero point of the circuit, ensuring that the interference of the thyristor on the power supply is reduced to a minimum. The zero-crossing signal can also be fed back to the control circuit. After processing by the control circuit, the thyristor is controlled accordingly to realize the function of AC chopping voltage regulation.

[0025] 4. The chip proposed by the present invention has a built-in over-temperature protection function, so that other cooperating circuits can understand and perform corresponding processing, realize the function of the temperature sensor, and prevent irreversible damage to the external circuit after overheating. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a block diagram of the internal principle of a thyristor driver chip with an AC zero-crossing detection function according to an embodiment of the present invention;

[0028] Figure 2 This is a simplified diagram of the internal principle of a thyristor driver chip with an AC zero-crossing detection function according to an embodiment of the present invention;

[0029] Figure 3 This is a simplified working circuit diagram of mode 1 of a thyristor driver chip with an AC zero-crossing detection function according to an embodiment of the present invention;

[0030] Figure 4 This is the working waveform corresponding to mode 1 of the thyristor driver chip with AC zero-crossing detection function according to an embodiment of the present invention;

[0031] Figure 5 This is a simplified diagram of the working circuit of mode 2 of a thyristor driver chip with an AC zero-crossing detection function according to an embodiment of the present invention;

[0032] Figure 6 This is the working waveform corresponding to mode 2 of the thyristor driver chip with AC zero-crossing detection function according to an embodiment of the present invention.

[0033] In the picture:

[0034] 1. Electrostatic protection module; 2. Zero-crossing detection bias current module; 3. Clamping circuit module; 4. Undervoltage lockout overvoltage protection module; 5. Reference voltage module; 6. Logic circuit module; 7. Overtemperature protection module. DETAILED DESCRIPTION

[0035] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments. They can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. By referring to these contents, ordinary technicians in this field should be able to understand other possible implementation methods and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0036] According to an embodiment of the present invention, a thyristor driver chip and an application circuit with an AC zero-crossing detection function are provided.

[0037] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. Figure 1-Figure 2 As shown, the thyristor driver chip with AC zero-crossing detection function according to an embodiment of the present invention includes an electrostatic protection module 1, a zero-crossing detection bias current module 2, a clamping circuit module 3, an undervoltage lockout overvoltage protection module 4, a reference voltage module 5, a logic circuit module 6 and an over-temperature protection module 7;

[0038] The electrostatic protection module 1 is electrically connected to the zero-crossing detection bias current module 2, the zero-crossing detection bias current module 2 is electrically connected to the clamping circuit module 3, the clamping circuit module 3 is electrically connected to the undervoltage lockout overvoltage protection module 4, the undervoltage lockout overvoltage protection module 4 is electrically connected to the reference voltage module 5, the reference voltage module 5 is electrically connected to the logic circuit module 6, and the logic circuit module 6 is electrically connected to the overtemperature protection module 7.

[0039] It should be explained that the electrostatic protection module 1 is used to improve the anti-static capability between the pins inside the entire driver chip by means of a built-in ESD circuit.

[0040] The zero-crossing detection bias current module 2 is used to detect the zero-crossing point of the external input AC voltage and send the detection result to the logic circuit module 6 for judgment.

[0041] The clamping circuit module 3 is used to clamp the zero-crossing detection signal source. Once the external AC signal is interfered with by more than a certain value, the clamping signal function is activated to protect the system from damage.

[0042] The undervoltage lockout overvoltage protection module 4 is used to send a signal to the logic circuit module 6 when the input AC power is insufficient or overvoltage occurs, so as to protect the entire driver chip from being damaged.

[0043] Specifically, when there is no EN enable signal input, the driver chip connects GATA and VDD poles through the internal circuit, thereby improving the static resistance of the driver chip to fast transient pulse interference and lightning surge.

[0044] The reference voltage module 5 is used to provide the normal working voltage to the weak current part of the entire thyristor.

[0045] The logic circuit module 6 is used to determine the zero-crossing detection signal, over-temperature protection point and re-temperature point, over-voltage protection point and other functions, whether the entire system needs to continue working, etc.

[0046] The driver chip responds to the external input EN signal (as long as the signal is a level signal with a signal strength of microamperes) through the internal logic circuit module 6 to control the internal MOS to open, and introduces current from the external VDD to achieve the amplification of the EN signal (microamperes), ensuring that no matter how large the trigger current (milliamperes) is, the thyristor can be driven to open without being affected by the ambient temperature.

[0047] The over-temperature protection module 7 is used to detect the temperature points inside and outside the entire driver chip. No matter whether the internal or external temperature is over-temperature, a signal is given to the logic circuit module 6. After the logic circuit module 6 makes a judgment, the GATE stops outputting the signal. When the temperature point returns to the reset temperature point, the GATE is judged whether to continue outputting the signal based on the enable signal.

[0048] In one embodiment, the zero-crossing detection bias current module 2 and the clamping circuit module 3 are composed of a resistor R1, an AND gate U1, a diode D1 and a diode D2;

[0049] One end of the resistor R1 is connected to the live wire L, the other end of the resistor R1 is respectively connected to the ZCD end, one end of the diode D1 and the first pin of the AND gate U1, the second pin of the AND gate U1 is connected to one end of the diode D2, the other end of the diode D2 is grounded, the other end of the diode D1 is connected to the undervoltage lockout overvoltage protection module 4 and the reference voltage module 5 and is grounded, and the third pin of the AND gate U1 is connected to the undervoltage lockout overvoltage protection module 4 and the reference voltage module 5.

[0050] In one embodiment, the undervoltage lockout overvoltage protection module 4 and the reference voltage module 5 are composed of a resistor R3, a resistor R4, an AND gate U2 and an operational amplifier OP1;

[0051] One end of the resistor R3 is connected to the other end of the diode D1, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and the first pin of the AND gate U2, the second pin of the AND gate U2 is connected to the neutral line N, the third pin of the AND gate U2 is respectively connected to the other end of the resistor R4 and the first pin of the operational amplifier OP1, the second pin of the operational amplifier OP1 is connected to the third pin of the AND gate U2, and the third pin and the fourth pin of the operational amplifier OP1 are both connected to the logic circuit module 6.

[0052] In one embodiment, the logic circuit module 6 is composed of an AND gate U3, an operational amplifier OP2, and a field effect transistor Q1;

[0053] The first pin of the AND gate U3 is respectively connected to the ZERO terminal and the fourth pin of the operational amplifier OP1, the second pin of the AND gate U3 is connected to the EN terminal, the third pin of the AND gate U3 is connected to the first pin of the operational amplifier OP2, the second pin of the operational amplifier OP2 is connected to the over-temperature protection module 7, the third pin of the operational amplifier OP2 is connected to the third pin of the operational amplifier OP1, the fourth pin of the operational amplifier OP2 is connected to the first pin of the field effect transistor Q1, the second pin of the field effect transistor Q1 is connected to the GATE terminal, and the third pin of the field effect transistor Q1 is grounded.

[0054] In one embodiment, the over-temperature protection module 7 is composed of a resistor R4, a resistor R5 and an AND gate U4;

[0055] The first pin of the AND gate U4 is connected to the second pin of the operational amplifier OP2, and the second pin of the AND gate U4 is connected to one end of the resistor R4 and one end of the resistor R5 respectively, and the other end of the resistor R4 is connected to V Z The other end of the resistor R5 is connected to the third pin of the AND gate U4 and is grounded.

[0056] It should be noted that once the driver chip detects that the internal chip or external circuit is overheated, ZERO will continue to output a square wave signal with a high and low level of 0.5 / 0.5ms until the temperature drops to within the reset temperature point and returns to the normal zero-crossing signal (a square wave signal with a high and low level of 1 / 9ms).

[0057] Among them, when the driver chip itself detects that a heat source exceeds the temperature protection point, no matter what signal EN is, the GATA pin of the driver chip will immediately stop outputting signals until the external temperature drops to the reset temperature point, then it will return to normal and be controlled by EN again.

[0058] According to another embodiment of the present invention, an application circuit of a thyristor driver chip with an AC zero-crossing detection function is used in AC zero-crossing detection.

[0059] In order to facilitate understanding of the above technical solutions of the present invention, the working principle or operation method of the present invention in actual process is described in detail below.

[0060] In actual application, take the input voltage of 220V, 50Hz AC as an example:

[0061] When the chip is working normally, the ZCD (zero crossing detector) voltage value will be clamped at a certain voltage value through the internal clamping circuit module 3. The voltage difference across the Rz resistor will change with the input live line L voltage, and then the current (I L ) to reflect the voltage change on the L line. Similarly, the chip will convert (VDD voltage, that is, N line voltage) into a reference current (I N ), the L line current (I L ) and the current of the N line (I N ) for comparison, when the voltage on the L line rises and crosses zero, I L Current greater than I N , when the voltage on the L line drops through zero, I L Current is less than I N .

[0062] By comparing these two current values, an internal comparator can determine the zero-crossing point of the AC power, thereby generating a zero-crossing signal ZERO output (a square wave signal with a high level of 1ms and a low level of 9ms).

[0063] This zero-crossing signal ZERO can be output separately to other circuits for use, and can also be given to the internal logic circuit module 6 for judgment. Only when EN is enabled at a high level, ZERO and EN jointly trigger the internal logic circuit, drive the internal MOS (transistor) to turn on, and GATE (control electrode) outputs an enable signal to drive the external thyristor to work and turn on.

[0064] The chip will detect the voltage value V at both ends of the built-in sampling resistor in real time. BE And with the reference voltage V Z For comparison, when the temperature rises to a certain temperature, the VBE voltage is less than the reference voltage Vz, and the comparator outputs the OTP over-temperature protection signal to the logic circuit module 6, turning off the GATE output. At the same time, ZERO will continue to output a square wave signal with a high and low level of 0.5 / 0.5ms, which is given to the external circuit for judgment until the temperature drops to the reset point and the chip returns to normal.

[0065] like Figure 3 and Figure 6 As shown, the driver chip proposed in the present invention can be operated in different modes by matching different application circuits to meet different needs, as follows:

[0066] like Figure 3 and Figure 4 As shown in the simplified circuit diagram and waveform diagram of mode 1 operation, the driver chip adopts the common power supply mode (the neutral terminal of AC power is also the VDD terminal of DC power), ensuring that the T1 pin of the thyristor is connected to VDD, so that the controlled thyristor is driven by a negative signal. ZCD is connected to the AC power line through a resistor (R) to realize zero-crossing detection. When the thyristor needs to be turned on, the I / O port continuously outputs a high level to the EN pin of the driver chip, and ZERO is left floating. At each AC power zero point, the GATE of the driver chip will output a drive signal to drive the thyristor to work until the I / O port stops outputting a high level and the thyristor is turned off at the next zero point.

[0067] Based on the working state of mode 1, its advantage is that the thyristor is only used as an electronic switch, and the thyristor is opened and operated at the AC zero point as much as possible, which reduces the thyristor conduction dead angle, reduces the disturbance of the thyristor chopping on the power supply voltage, and reduces the electromagnetic radiation interference of the circuit to the entire power grid. Its disadvantage is that the AC voltage regulation chopping function cannot be realized.

[0068] like Figure 5 and Figure 6The simplified circuit diagram and waveform diagram of Mode 2 operation are shown. The driver chip uses a common power supply mode (the neutral terminal of the AC power is also the VDD terminal of the DC power). Ensure that the T1 pin of the thyristor is connected to VDD, so that the controlled thyristor is driven by a negative signal. ZCD is connected to the AC power line through a resistor to implement zero-crossing detection. When the driver chip detects the AC zero crossing, ZERO outputs a zero-crossing signal (a square wave signal with a high level of 1ms and a low level of 9ms) and transmits it to the MCU's I / O port. The MCU makes a corresponding judgment based on the zero-crossing signal provided by the driver chip and can immediately or after a certain delay output a high-level enable signal EN, which is then fed back to the driver chip. At this time, the GATE terminal of the driver chip immediately outputs a drive signal to the thyristor, triggering the thyristor to operate. When the EN signal output by the MCU is low, the GATE terminal immediately stops outputting the drive signal, and the thyristor remains in the off state at the next AC zero crossing.

[0069] In the mode 2 working state, its advantage is that the driver chip can very accurately control the conduction of the thyristor, so that the output power of the entire circuit is in a relatively stable state, but its disadvantage is that the chopping performance of the thyristor is utilized, which will cause greater electromagnetic interference.

[0070] To sum up, with the help of the above-mentioned technical solution of the present invention, the driver chip proposed by the present invention can not only provide AC zero-crossing detection function, but also has over-temperature, overvoltage protection and other functions. At the same time, considering the traditional bidirectional thyristor, the trigger current of the bidirectional thyristor becomes larger at low temperatures, and the trigger current itself is too large, resulting in insufficient driving current when the single-chip microcomputer directly drives and controls, and the problem of inability to drive the thyristor to open normally. The single-chip microcomputer is used to amplify the excessively small driving current, so that the thyristor can be opened with only a very small driving signal and time, avoiding the problem of insufficient drive and inability to control the thyristor. The AC zero-crossing detection function proposed by the present invention accurately detects the zero-crossing point of the AC power through an external resistor, and provides it to other circuits for AC zero-crossing judgment, thereby making up for the zero-crossing detection circuit built by some components. The components themselves have certain accuracy problems, making the detection accuracy higher. At the same time, the proposed driver chip has an over-temperature protection function, which needs to be as close to the heat source as possible. Once the temperature exceeds the protection point, even if there is still an external control signal given to the driver chip, the driver chip will not have a signal output. Only when the temperature is lower than the reset temperature can the driver chip continue to restore the control function under the control of the external signal, thereby avoiding the situation where some traditional thyristors lose control and remain in a working state once the junction temperature exceeds the tolerance, thereby reducing the risk of burning components and external circuits causing fires.

[0071] The driver chip proposed in this utility model integrates the zero-crossing detection function, over-temperature protection function, and amplifier circuit together to achieve high integration and miniaturization. When detecting the zero point of the alternating current, it can be used by both the internal logic circuit and the external circuit. When driving the thyristor, it opens at the zero point of the circuit to ensure that the interference of the thyristor on the power supply is reduced to a minimum. The zero-crossing signal can also be fed back to the control circuit. After the control circuit processes it, it controls the thyristor accordingly to realize the function of AC chopping voltage regulation. The chip proposed in this utility model has a built-in over-temperature protection function. Once it enters the over-temperature protection state, the zero-crossing signal output terminal will output a notification signal so that other cooperating circuits can understand and perform corresponding processing, realizing the function of the temperature sensor and preventing irreversible damage to the external circuit after overheating.

[0072] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. The thyristor driver chip with AC zero-crossing detection function is characterized by: It comprises an electrostatic protection module (1), a zero-crossing detection bias current module (2), a clamping circuit module (3), an undervoltage lockout overvoltage protection module (4), a reference voltage module (5), a logic circuit module (6) and an overtemperature protection module (7); The electrostatic protection module (1) is electrically connected to the zero-crossing detection bias current module (2), the zero-crossing detection bias current module (2) is electrically connected to the clamping circuit module (3), the clamping circuit module (3) is electrically connected to the undervoltage lockout overvoltage protection module (4), the undervoltage lockout overvoltage protection module (4) is electrically connected to the reference voltage module (5), the reference voltage module (5) is electrically connected to the logic circuit module (6), and the logic circuit module (6) is electrically connected to the overtemperature protection module (7).

2. The thyristor driver chip with AC zero-crossing detection function according to claim 1, characterized in that: The zero-crossing detection bias current module (2) and the clamping circuit module (3) are composed of a resistor R1, an AND gate U1, a diode D1 and a diode D2; One end of the resistor R1 is connected to the live wire L, the other end of the resistor R1 is respectively connected to the ZCD end, one end of the diode D1 and the first pin of the AND gate U1, the second pin of the AND gate U1 is connected to one end of the diode D2, the other end of the diode D2 is grounded, the other end of the diode D1 is connected to the undervoltage lockout overvoltage protection module (4) and the reference voltage module (5) and is also grounded, and the third pin of the AND gate U1 is connected to the undervoltage lockout overvoltage protection module (4) and the reference voltage module (5).

3. The thyristor driver chip with AC zero-crossing detection function according to claim 2, characterized in that: The undervoltage lockout overvoltage protection module (4) and the reference voltage module (5) are composed of a resistor R3, a resistor R4, an AND gate U2 and an operational amplifier OP1; One end of the resistor R3 is connected to the other end of the diode D1, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and the first pin of the AND gate U2, the second pin of the AND gate U2 is connected to the neutral line N, the third pin of the AND gate U2 is respectively connected to the other end of the resistor R4 and the first pin of the operational amplifier OP1, the second pin of the operational amplifier OP1 is connected to the third pin of the AND gate U2, and the third pin and the fourth pin of the operational amplifier OP1 are both connected to the logic circuit module (6).

4. The thyristor driver chip with AC zero-crossing detection function according to claim 3, characterized in that: The logic circuit module (6) is composed of an AND gate U3, an operational amplifier OP2 and a field effect transistor Q1; The first pin of the AND gate U3 is connected to the ZERO terminal and the fourth pin of the operational amplifier OP1 respectively, the second pin of the AND gate U3 is connected to the EN terminal, the third pin of the AND gate U3 is connected to the first pin of the operational amplifier OP2, the second pin of the operational amplifier OP2 is connected to the over-temperature protection module (7), the third pin of the operational amplifier OP2 is connected to the third pin of the operational amplifier OP1, the fourth pin of the operational amplifier OP2 is connected to the first pin of the field effect transistor Q1, the second pin of the field effect transistor Q1 is connected to the GATE terminal, and the third pin of the field effect transistor Q1 is grounded.

5. The thyristor driver chip with AC zero-crossing detection function according to claim 4, characterized in that: The over-temperature protection module (7) is composed of a resistor R4, a resistor R5 and an AND gate U4; The first pin of the AND gate U4 is connected to the second pin of the operational amplifier OP2, the second pin of the AND gate U4 is connected to one end of the resistor R4 and one end of the resistor R5 respectively, and the other end of the resistor R4 is connected to V Z The other end of the resistor R5 is connected to the third pin of the AND gate U4 and is grounded.

6. The thyristor driver chip with AC zero-crossing detection function according to claim 5, characterized in that: When the live line voltage rises and passes through zero, the live line current is greater than the neutral line current. When the live line voltage drops and passes through zero, the live line current is less than the neutral line current.

7. The application circuit of the thyristor driver chip with AC zero-crossing detection function is characterized by: Used to implement the application of a thyristor driver chip with AC zero-crossing detection function described in any one of claims 1-6 in AC zero-crossing detection.

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