High-voltage driving circuit

Abstract

The invention relates to a high-voltage driving circuit, which is characterized in that an analog input signal is converted into a digital input signal through an input module, and then a high-side input signal and a low-side input signal are simultaneously generated by a level conversion module according to the digital input signal so as to respectively drive a high-side driving module and a low-side driving module to output corresponding driving signals. Under the same packaging pin, the high-side driving module and the low-side driving module are subjected to different bonding selections with the output pin according to needs, better compatibility is provided for application circuit design, the circuit structure is simple, and no external device is needed.

Description

Technical Field

[0001] This application relates to the field of driving technology, and particularly to a high-voltage driving circuit. Background Art

[0002] In applications such as industrial sensors, proximity sensors, PLCs, and light barriers, a driving chip can drive a heavy load through a sensor input signal and provide level conversion, and can decouple the input sensor signal from the output signal, providing higher voltage and current capabilities.

[0003] Conventional driving chips are divided into low-side (NPN type) driving chips and high-side (PNP type) driving chips, as shown in FIGS. 1(a) and 1(b). In the low-side (NPN type) driving chip, VN is the low-level power supply on the driving side, DN is the open-drain output driving signal, and PI and NI are input signals. When PI - NI > vth, NMOS pulls the DN signal low to VN, achieving the NPN driving function. Here, vth is the comparator input threshold voltage. In the high-side (PNP type) driving chip, VP is the high-level power supply on the driving side, DP is the open-drain output driving signal, and PI and NI are input signals. When PI - NI < vth, PMOS pulls the DP signal high to VP, achieving the PNP driving function.

[0004] However, due to the differences in output signals, it is difficult to achieve a compatible design between conventional low-side (NPN type) driving chips and high-side (PNP type) driving chips. Additional external devices are required to meet the requirements of the application circuit compatible design. Summary of the Invention

[0005] This application provides a high-voltage driving circuit that can achieve high-side and low-side driving compatibility without relying on external devices.

[0006] A high-voltage driving circuit includes:

[0007] An input module, configured to receive an analog input signal and convert the analog input signal into a digital input signal;

[0008] A level conversion module, connected to the input module, configured to generate a high-side input signal and a low-side input signal respectively according to the digital input signal;

[0009] A high-side driving module, connected to the level conversion module, configured to output a high-side driving signal under the excitation of the high-side input signal;

[0010] A low-side driving module, connected to the level conversion module, configured to output a low-side driving signal under the excitation of the low-side input signal;

[0011] Wherein, one of the high-side driving module and the low-side driving module is selectively connected to the output pin of the high-voltage driving circuit.

[0012] In one embodiment, the analog input signal includes a first analog signal and a second analog signal, the digital input signal includes a first digital signal, and the input module is further configured to:

[0013] Detect the module temperatures of the high-side driving module and the low-side driving module;

[0014] If the voltage difference between the first analog signal and the second analog signal is greater than a first threshold voltage and the module temperature does not exceed the temperature threshold, convert the voltage difference to obtain the first digital signal;

[0015] The level conversion module is further configured to generate the high-side input signal and the low-side input signal respectively according to the first digital signal.

[0016] In one embodiment, the digital input signal includes a second digital signal, and the input module is further configured to:

[0017] If the voltage difference is less than a second threshold voltage or the module temperature exceeds the temperature threshold, convert the voltage difference to obtain the second digital signal;

[0018] The level conversion module is further configured to stop generating the high-side input signal and the low-side input signal according to the second digital signal.

[0019] In one embodiment, the input module includes:

[0020] A first comparator, two input terminals of the first comparator respectively receive the first analog signal and the second analog signal in a one-to-one correspondence, and are configured to compare the voltage difference with the first threshold voltage and the second threshold voltage respectively, and output a comparison signal;

[0021] An over-temperature detection unit, configured to detect whether the temperatures of the high-side driving module and the low-side driving module exceed the temperature threshold, and output a temperature detection signal;

[0022] A first logic gate circuit, connected to the first comparator and the over-temperature detection unit respectively, and configured to output the digital input signal according to the comparison signal and the temperature detection signal.

[0023] In one embodiment, the high-voltage driving circuit further includes:

[0024] An overcurrent detection module, which is respectively connected to the input module, the high-side drive module and the low-side drive module, is configured to output an overcurrent detection signal if it receives the first digital signal and determines that the high-side difference between the high-side drive signal and the high-side voltage threshold is greater than the third threshold voltage, or the low-side difference between the low-side drive signal and the low-side voltage threshold is greater than the fourth threshold voltage.

[0025] In one embodiment, the overcurrent detection module is further configured to stop outputting the overcurrent detection signal if it receives the second digital signal, or determines that the high-side difference between the high-side drive signal and the high-side voltage threshold is less than the fifth threshold voltage, and the low-side difference between the low-side drive signal and the low-side voltage threshold is less than the sixth threshold voltage.

[0026] In one embodiment, the overcurrent detection module includes:

[0027] A transistor NM0, the first connection end of the transistor NM0 is connected to the first power supply end, and the second connection end of the transistor NM0 is connected to the second power supply end;

[0028] A second comparator, the positive phase end of the second comparator is configured to receive the high-side voltage threshold, the negative phase end of the second comparator is configured to receive the high-side drive signal, and the second comparator is configured to output a high-side voltage comparison signal according to the high-side drive signal and the high-side voltage threshold;

[0029] A second logic gate circuit, which is respectively connected to the output end of the second comparator and the input module, is configured to output a first logic signal according to the digital input signal and the high-side voltage comparison signal;

[0030] A third comparator, the positive phase end of the third comparator is configured to receive the low-side drive signal, the negative phase end of the third comparator is configured to receive the low-side voltage threshold, and the third comparator is configured to output a low-side voltage comparison signal according to the low-side drive signal and the low-side voltage threshold;

[0031] A third logic gate circuit, which is respectively connected to the output end of the third comparator and the input module, is configured to output a second logic signal according to the digital input signal and the low-side voltage comparison signal;

[0032] A fourth logic gate circuit, which is respectively connected to the second logic gate circuit, the third logic gate circuit and the gate of the transistor NM0, is configured to control the on / off of the transistor NM0 according to the first logic signal and the second logic signal, so as to output or stop outputting the overcurrent detection signal at the first connection end of the transistor NM0.

[0033] In one embodiment, the high-side drive module includes: transistor PM1, transistor PM2, transistor PM3, transistor PM4, and current source IB1; the control terminals of transistor PM1 and transistor PM2 are commonly connected and connected to the level conversion module for receiving the high-side input signal; the first connection terminals of transistor PM1 and transistor PM2 are commonly connected for receiving a first high-side power supply voltage; the second connection terminal of transistor PM1 is connected to the first connection terminal of transistor PM3; the second connection terminal of transistor PM2 is connected to the first connection terminal of transistor PM4; the control terminal and the second connection terminal of transistor PM3, and the control terminal of transistor PM4 are commonly connected and connected to the first end of current source IB1; the second end of current source IB1 is connected to a second high-side power supply voltage; the second connection terminal of transistor PM4 is used to output the high-side drive signal.

[0034] In one embodiment, the high-side drive module further includes:

[0035] An ideal diode circuit, the anode of the ideal diode circuit is connected to the second connection terminal of transistor PM4, and the cathode of the ideal diode circuit is used to output the high-side drive signal.

[0036] In one embodiment, the low-side drive module includes: transistor NM1, transistor NM2, transistor NM3, transistor NM4, and current source IB2; the first end of current source IB2 is used to receive a first low-side power supply voltage; the control terminal and the first connection terminal of transistor NM1, the second end of current source IB2, and the control terminal of transistor NM2 are commonly connected; the second connection terminal of transistor NM1 is connected to the first connection terminal of transistor NM3; the control terminals of transistor NM3 and transistor NM4 are commonly connected and connected to the level conversion module for receiving the low-side input signal; the first connection terminal of transistor NM2 is used to output the low-side drive signal; the second connection terminal of transistor NM2 is connected to the first connection terminal of transistor NM4; the second connection terminals of transistor NM3 and transistor NM4 are commonly connected for receiving a second low-side power supply voltage.

[0037] The above-mentioned input module converts the analog input signal into a digital input signal, and then the level conversion module generates a high-side input signal and a low-side input signal according to the digital input signal to respectively drive the high-side drive module and the low-side drive module to output corresponding drive signals, and on the same package pin, different bonding selections of the high-side drive module and the low-side drive module with the output pin are made according to needs, providing better compatibility for the application circuit design, with a simple circuit structure and without the need to rely on external devices. Brief Description of the Drawings

[0038] Fig. 1(a) is a structural diagram of a conventional NPN-type driving circuit;

[0039] Fig. 1(b) is a structural diagram of a conventional PNP-type driving circuit;

[0040] Figure 2 is a structural block diagram of a high-voltage driving circuit according to an embodiment of the present application;

[0041] Figure 3 is a structural block diagram of a high-voltage driving circuit according to another embodiment of the present application;

[0042] Figure 4 is a structural block diagram of a high-voltage driving circuit according to another embodiment of the present application;

[0043] Figure 5 is a circuit structural diagram of a high-voltage driving circuit according to an embodiment of the present application;

[0044] Figure 6 is a circuit structural diagram of a high-voltage driving circuit according to another embodiment of the present application;

[0045] Figure 7 is a circuit structural diagram of a high-voltage driving circuit according to another embodiment of the present application;

[0046] Figure 8 is a circuit structural diagram of a high-voltage driving circuit according to another embodiment of the present application. Detailed Description of the Embodiments

[0047] It should be understood that the specific embodiments described herein are only for explaining the present application and are not used to limit the present application.

[0048] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0049] It should be noted that all the directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly. The described connection can be a direct connection or an indirect connection.

[0050] In addition, in this application, descriptions such as "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0051] Figure 2 is a structural block diagram of a high-voltage drive circuit for an embodiment. As Figure 2 shown, the high-voltage drive circuit includes an input module 110, a level conversion module 120, a high-side drive module 130, and a low-side drive module 140; the input module 110 is configured to receive an analog input signal and convert the analog input signal into a digital input signal; the level conversion module 120 is connected to the input module 110 and is configured to generate a high-side input signal and a low-side input signal respectively according to the digital input signal; the high-side drive module 130 is connected to the level conversion module 120 and is configured to output a high-side drive signal under the excitation of the high-side input signal; the low-side drive module 140 is connected to the level conversion module 120 and is configured to output a low-side drive signal under the excitation of the low-side input signal; wherein, the high-side drive module 130 and the low-side drive module 140 are alternatively connected to the output pin of the high-voltage drive circuit.

[0052] The analog input signal can be a high-voltage wide-range signal, and the voltage range can exceed the power supply voltage of the circuit. In this way, high-voltage wide-voltage input can be realized to meet more input requirements; the input module 110 can convert the analog input signal into a digital input signal with the same phase and low delay, so that the level conversion module 120 can generate the drive signals required by the high-side drive module 130 and the low-side drive module 140 respectively according to the digital input signal. Among them, the level conversion module 120 can be a high-voltage level conversion module 120 to achieve high driving ability for the low-side drive module 140.

[0053] The level conversion module 120 can generate a high-side input signal and a low-side input signal at the same time, so as to drive the high-side drive module 130 and the low-side drive module 140 to output drive signals at the same time. When the high-voltage drive circuit is packaged, one of the high-side drive module 130 and the low-side drive module 140 is alternatively selected to be connected to the output pin of the high-voltage drive circuit to obtain the high-voltage drive circuit of this type of drive. Specifically, if the high-side drive module 130 is connected to the output pin of the high-voltage drive circuit, the obtained high-voltage drive circuit is a high-side drive circuit; if the low-side drive module 140 is connected to the output pin of the high-voltage drive circuit, the obtained high-voltage drive circuit is a low-side drive circuit.

[0054] In this way, the analog input signal is converted into a digital input signal by the input module 110, and then the level conversion module 120 generates a high-side input signal and a low-side input signal according to the digital input signal simultaneously, so as to drive the high-side drive module 130 and the low-side drive module 140 to output corresponding drive signals respectively. And at the same package pin, different bonding selections of the high-side drive module 130 and the low-side drive module 140 are made with the output pin according to needs, providing better compatibility for the application circuit design. The circuit structure is simple and does not require external devices.

[0055] In one embodiment, the analog input signal includes a first analog signal and a second analog signal, the digital input signal includes a first digital signal, and the input module 110 is further configured to: detect the module temperatures of the high-side drive module 130 and the low-side drive module 140; if the voltage difference between the first analog signal and the second analog signal is greater than a first threshold voltage and the module temperature does not exceed the temperature threshold, convert the first digital signal according to the voltage difference; the level conversion module 120 is further configured to generate a high-side input signal and a low-side input signal according to the first digital signal respectively.

[0056] It can be understood that the digital input signal may include a first digital signal, which is used to drive the level conversion module 120 to generate a high-side input signal and a low-side input signal, and the input module 110 generates the first digital signal only when the voltage difference between the first analog signal and the second analog signal is greater than the first threshold voltage and the module temperature does not exceed the temperature threshold.

[0057] Specifically, the conversion output of the input module 110 can adopt a double-input signal control method, that is, the digital input signal output is determined by the magnitude relationship between the voltage difference between the first analog signal and the second analog signal and the first threshold voltage. In addition, since conventional driver chips often only have the ability of output driving and lack output current protection. If the output low-side drive signal is short-circuited to the external high-side power rail, it is easy to increase the overcurrent of the chip, raise the temperature and damage the chip; if the output high-side drive signal is short-circuited to the external low-side power rail, it also increases the overcurrent of the chip and raises the temperature. In view of this, the present application detects the module temperatures of the high-side drive module 130 and the low-side drive module 140, and incorporates the module temperature requirements into the consideration range of the input module 110 for converting and outputting the digital input signal, so as to ensure that the high-side input signal and the low-side input signal are generated only when the temperature does not exceed the temperature threshold, and further realize the high-side drive and the low-side drive, ensuring the safety of the overall circuit. Among them, the module temperature includes the temperatures of both the high-side drive module 130 and the low-side drive module 140, and the module temperature not exceeding the temperature threshold means that both temperatures do not exceed the temperature threshold.

[0058] In this way, only when both the analog input signal and the module temperature meet the requirements, the high-side input signal and the low-side input signal for driving the high-side driving module 130 and the low-side driving module 140 are generated respectively, avoiding the operation of the driving module at high temperature and ensuring the safety of the overall circuit.

[0059] In one embodiment, the digital input signal includes a second digital signal, and the input module 110 is further configured to: if the voltage difference is less than the second threshold voltage, or the module temperature exceeds the temperature threshold, convert the voltage difference to obtain the second digital signal; the level conversion module 120 is further configured to stop generating the high-side input signal and the low-side input signal according to the second digital signal.

[0060] Wherein, the module temperature includes the temperatures of the high-side driving module 130 and the low-side driving module 140, and the module temperature exceeding the temperature threshold means that the temperature of at least one module exceeds the temperature threshold. The second threshold voltage is less than the first threshold voltage.

[0061] It can be understood that if either the voltage difference or the module temperature does not meet the requirements, it indicates that the analog input signal does not meet the driving requirements, or the temperatures of the two driving modules are likely to cause safety accidents. At this time, the input module 110 converts the voltage difference to obtain the second digital signal to drive the level conversion module 120 to stop generating the high-side input signal and the low-side input signal, ensuring the safety of the circuit.

[0062] In one embodiment, as Figure 3 shown, the input module 110 includes a first comparator 111, an overtemperature detection unit 112, and a first logic gate circuit 113. The two input terminals of the first comparator 111 respectively receive the first analog signal and the second analog signal in a one-to-one correspondence, and are used to compare the voltage difference with the first threshold voltage and the second threshold voltage respectively, and output a comparison signal; the overtemperature detection unit 112 is used to detect whether the temperatures of the high-side driving module 130 and the low-side driving module 140 exceed the temperature threshold, and output a temperature detection signal; the first logic gate circuit 113 is respectively connected to the first comparator 111 and the overtemperature detection unit 112, and is used to output a digital input signal according to the comparison signal and the temperature detection signal.

[0063] It can be understood that the first comparator 111 can be a comparator with a hysteresis function, so it has a high anti-noise effect and can convert the analog input signal into a digital logic signal with the same phase and low delay; the first analog signal and the second analog signal are respectively Figure 3One of the PI and NI. According to the comparison result of the first comparator 111, the value of the comparison signal output by it can have two cases; similarly, according to the detection result of the overtemperature detection unit 112, the value of the temperature detection signal also has two cases. The first logic gate circuit 113 outputs a digital input signal with two cases according to different combinations of the value of the comparison signal and the value of the temperature detection signal.

[0064] Specifically, in one embodiment, the level conversion module 120 can be effectively driven by a high level, and the first logic gate circuit 113 can be an AND gate circuit. When the voltage difference between the first analog signal and the second analog signal is greater than the first threshold voltage, the comparison signal can be a high level. When the module temperature does not exceed the temperature threshold, the temperature detection signal can be a high level; therefore, when the voltage difference between the first analog signal and the second analog signal is greater than the first threshold voltage and the module temperature does not exceed the temperature threshold, the first digital signal output after the AND operation by the first logic gate circuit 113 is a high level, thereby driving the level conversion module 120 to output a high-side input signal and a low-side input signal. On the contrary, if the voltage difference is less than the second threshold voltage, or the module temperature exceeds the temperature threshold, at least one of the comparison signal and the temperature detection signal is a low level, and the second digital signal output after the AND operation by the first logic gate circuit 113 is a low level, so that the level conversion module 120 stops generating the high-side input signal and the low-side input signal.

[0065] The above input module 110 has a simple structure, is easy to manufacture and has a low cost. Due to its high anti-noise effect and high precision, and in addition, considering the temperature, it can avoid the unstable state of the backend driving module due to too high temperature, thus protecting the circuit.

[0066] In one embodiment, as Figure 4 shown, the high-voltage driving circuit further includes an overcurrent detection module 150. The overcurrent detection module 150 is respectively connected to the input module 110, the high-side driving module 130 and the low-side driving module 140, and is used for outputting an overcurrent detection signal if it receives a first digital signal and determines that the high-side difference between the high-side driving signal and the high-side voltage threshold is greater than a third threshold voltage, or the low-side difference between the low-side driving signal and the low-side voltage threshold is greater than a fourth threshold voltage.

[0067] Wherein, the high-side difference is the voltage difference between the high-side driving signal and the high-side voltage threshold. When the high-side difference is greater than the third threshold voltage, it indicates that an overcurrent phenomenon occurs in the high-side driving; similarly, the low-side difference is the voltage difference between the low-side driving signal and the low-side voltage threshold. When the low-side difference is greater than the fourth threshold voltage, it indicates that an overcurrent phenomenon occurs in the low-side driving; at this time, an overcurrent detection signal is output in combination with the reception situation of the first digital signal.

[0068] It can be understood that there are two cases where the overcurrent signal is output in this embodiment. One is that the overcurrent detection module 150 receives the first digital signal and determines that the high-side difference between the high-side drive signal and the high-side voltage threshold is greater than the third threshold voltage; the other is that the overcurrent detection module 150 receives the first digital signal and determines that the low-side difference between the low-side drive signal and the low-side voltage threshold is greater than the fourth threshold voltage. As long as at least one of the cases occurs, the overcurrent detection signal will be output to indicate that there is an overcurrent situation. The first digital signal is used to drive the signal output of the high-side drive module 130 and the low-side drive module 140 to enable the effective operation of the high-voltage drive circuit. By including the first digital signal in the consideration of overcurrent detection, it is possible to determine whether there is an overcurrent only when the circuit is operating effectively, thus preventing false triggering of the overcurrent detection signal and improving the accuracy of overcurrent detection.

[0069] In one embodiment, the overcurrent detection module 150 is further configured to stop outputting the overcurrent detection signal if it receives the second digital signal, or determines that the high-side difference between the high-side drive signal and the high-side voltage threshold is less than the fifth threshold voltage, and the low-side difference between the low-side drive signal and the low-side voltage threshold is less than the sixth threshold voltage.

[0070] The fifth threshold voltage is less than the third threshold voltage, and the sixth threshold voltage is less than the fourth threshold voltage. It can be understood that there are two cases where the output of the overcurrent detection signal stops. One is that the overcurrent detection module 150 receives the second digital signal; the other is that it is determined that the high-side difference between the high-side drive signal and the high-side voltage threshold is less than the fifth threshold voltage, and the low-side difference between the low-side drive signal and the low-side voltage threshold is less than the sixth threshold voltage. As long as at least one of the cases occurs, the output of the overcurrent detection signal will stop to indicate that there is no overcurrent situation.

[0071] When the second digital signal is received, it indicates that the high-voltage drive circuit is not operating effectively, and it is invalid to detect the overcurrent situation at this time, so the output of the overcurrent detection signal can be stopped; when the high-side difference is less than the fifth threshold voltage, it indicates that there is no overcurrent phenomenon in the high-side drive, and when the low-side difference is less than the sixth threshold voltage, it indicates that there is no overcurrent phenomenon in the low-side drive. Therefore, when these two cases exist, the output of the overcurrent detection signal is also stopped.

[0072] In one embodiment, as Figure 5As shown in the figure, the overcurrent detection module 150 includes: transistor NM0, second comparator 151, second logic gate circuit 153, third comparator 152, third logic gate circuit 154, and fourth logic gate circuit 155. The first connection terminal of transistor NM0 is connected to the first power supply terminal, and the second connection terminal of transistor NM0 is connected to the second power supply terminal; second comparator 151, the positive phase terminal of second comparator 151 is used to receive the high-side voltage threshold VCC, the negative phase terminal of second comparator 151 is used to receive the high-side drive signal DP, and second comparator 151 is used to output a high-side voltage comparison signal according to the high-side drive signal DP and the high-side voltage threshold VCC; second logic gate circuit 153 is respectively connected to the output terminal of second comparator 151 and input module 110, and is used to output a first logic signal according to the digital input signal and the high-side voltage comparison signal; the positive phase terminal of third comparator 152 is used to receive the low-side drive signal DN, the negative phase terminal of third comparator 152 is used to receive the low-side voltage threshold VSS, and third comparator 152 is used to output a low-side voltage comparison signal according to the low-side drive signal DN and the low-side voltage threshold VSS; third logic gate circuit 154 is respectively connected to the output terminal of third comparator 152 and input module 110, and is used to output a second logic signal according to the digital input signal and the low-side voltage comparison signal; fourth logic gate circuit 155 is respectively connected to second logic gate circuit 153, third logic gate circuit 154, and the gate of transistor NM0, and is used to control the on / off of transistor NM0 according to the first logic signal and the second logic signal, so as to output or stop outputting an overcurrent detection signal at the first connection terminal OCP of transistor NM0.

[0073] Among them, the second logic gate circuit 153 and the third logic gate circuit 154 can be AND gate circuits, the fourth logic gate circuit 155 can be an OR gate circuit, the transistor NM0 can be an NMOS transistor, the first digital signal in the digital input signal can be a high level, and the second digital signal can be a low level. In one embodiment, the transistor NM0 can be a high-voltage LDNMOS transistor.

[0074] Specifically, when the output module outputs the first digital signal, and the high-side difference between the high-side drive signal and the high-side voltage threshold is greater than the third threshold voltage, that is, when the high-side voltage comparison signal is a high level, the second logic gate circuit 153 outputs a high level. At this time, no matter what level the third logic gate circuit 154 outputs, the fourth logic gate circuit 155 outputs a high level, thereby turning on the transistor NM0, and outputting a low level at the first connection terminal of the transistor NM0 as an overcurrent detection signal; similarly, when the output module outputs the first digital signal, and the high-side difference between the low-side drive signal and the low-side voltage threshold is greater than the fourth threshold voltage, that is, when the low-side voltage comparison signal is a high level, the second logic gate circuit 153 outputs a high level to obtain an overcurrent detection signal at the first connection terminal OCP of the transistor NM0.

[0075] When the second digital signal is output by the output module, regardless of the levels output by the second comparator 151 and the third comparator 152, the second logic gate circuit 153 and the third logic gate circuit 154 will both output low levels. As a result, the fourth logic gate circuit 155 outputs a low level, the transistor NM0 is turned off, and its first connection end is equal to the pull-up voltage. Therefore, the output is a high level, and the overcurrent detection signal stops being output. In addition, when the high-side difference between the high-side drive signal and the high-side voltage threshold is less than the fifth threshold voltage, and the low-side difference between the low-side drive signal and the low-side voltage threshold is less than the sixth threshold voltage, the second logic gate circuit 153 and the third logic gate circuit 154 will both output low levels. Eventually, the first connection end of the transistor NM0 outputs a high level, and the overcurrent detection signal also stops being output.

[0076] In this way, the overcurrent phenomenon can be detected by using the above open-drain output circuit. The staff can know whether there is an overcurrent phenomenon according to the output situation of the overcurrent detection signal, and the circuit structure is simple.

[0077] In one embodiment, as Figure 6 shown, the high-side drive module 130 includes a transistor PM1, a transistor PM2, a transistor PM3, a transistor PM4, and a current source IB1. The control ends of the transistor PM1 and the transistor PM2 are commonly connected and connected to the level conversion module 120 for receiving the high-side input signal. The first connection ends of the transistor PM1 and the transistor PM2 are commonly connected for receiving the first high-side power supply voltage. The second connection end of the transistor PM1 is connected to the first connection end of the transistor PM3. The second connection end of the transistor PM2 is connected to the first connection end of the transistor PM4. The control end and the second connection end of the transistor PM3, and the control end of the transistor PM4 are commonly connected and connected to the first end of the current source IB1. The second end of the current source IB1 is connected to the second high-side power supply voltage. The second connection end of the transistor PM4 is used to output the high-side drive signal.

[0078] The high-side drive module 130 provides high-side low-voltage drive, and its power rail ranges from the first high-side power voltage to the second high-side power voltage. The voltage value of the first high-side power voltage can be VCC, and the voltage value of the second high-side power voltage can be VSSH. VCC can be the power supply for the drive circuit, and VSSH is the high-side ground of the drive circuit, which can be designed as VCC - 3.3V. It can be understood that the transistor PM3 and the transistor PM4 form a current mirror that provides the high-side drive signal, and the transistor PM1 and the transistor PM2 form a drive switch to control the output of the high-side drive signal. The current source IB1 is used to provide the reference bias current Ib1. Among them, the high-side drive signal can be a current signal. The ratio of the transistor PM4 to the transistor PM3, and the ratio of the transistor PM2 to the transistor PM1 are both the same ratio m. Therefore, the current value of the final high-side drive signal is m * Ib1.

[0079] In this way, by adjusting the ratio of the transistors on the two branches and the reference bias current of the current source IB1, the current value of the high-side drive signal can be further adjusted to achieve high drive current output.

[0080] In one embodiment, the high-side drive module 130 further includes an ideal diode circuit UD1, as Figure 6 shown. The anode of the ideal diode circuit UD1 is connected to the second connection end of the transistor PM4, and the cathode of the ideal diode circuit UD1 is used to output the high-side drive signal.

[0081] It can be understood that without taking any measures, if an external voltage higher than the VCC power supply is loaded from the second connection end of the transistor PM4, the voltage will conduct to the VCC power supply through the parasitic ideal diode in the P-type MOS transistor in the high-side drive module 130, causing the VCC power supply to be affected by this voltage. Therefore, the ideal diode circuit UD1 is designed so that when the voltage of the VCC power supply is less than the external voltage, the external voltage will not be back-fed to the VCC power supply through the second connection end of the transistor PM4, ensuring the stability of the voltage of the VCC power supply; and the conduction voltage drop of the ideal diode circuit UD1 is very low and does not affect the conduction performance during normal operation.

[0082] In this way, by setting the ideal diode circuit UD1 at the second connection end of the transistor PM4, external abnormal high voltage from the second connection end of the transistor PM4 can be effectively prevented from being back-fed to VCC, ensuring the safety of the circuit.

[0083] In one embodiment, as Figure 7As shown, the low-side drive module 140 includes: transistor NM1, transistor NM2, transistor NM3, transistor NM4, and current source IB2; the first end of the current source IB2 is used to receive the first low-side power supply voltage; the control end and the first connection end of the transistor NM1, the second end of the current source IB2, and the control end of the transistor NM2 are commonly connected; the second connection end of the transistor NM1 is connected to the first connection end of the transistor NM3; the control end of the transistor NM3 and the control end of the transistor NM4 are commonly connected and are connected to the level conversion module 120 for receiving a low-side input signal; the first connection end of the transistor NM2 is used to output a low-side drive signal; the second connection end of the transistor NM2 is connected to the first connection end of the transistor NM4; the second connection end of the transistor NM3 and the second connection end of the transistor NM4 are commonly connected for receiving the second low-side power supply voltage.

[0084] The low-side drive module 140 is a low-side low-voltage drive, and its power rail is from the first low-side power supply voltage to the second low-side power supply voltage. Among them, the voltage value of the first low-side power supply voltage can be VDDL, and the voltage value of the second low-side power supply voltage can be VSS. VDDL is the low-side power supply of the drive circuit, designed to be 3.3V, and VSS is the reference ground of the drive circuit. It can be understood that the transistor NM1 and the transistor NM2 form a current mirror that provides the low-side drive signal, and the transistor NM3 and the transistor NM4 form a drive switch to control the output of the low-side drive signal. The current source IB2 is used to provide a reference bias current Ib2. Among them, the low-side drive signal can be a current signal, and the transistor NM1 and the transistor NM2, as well as the transistor NM3 and the transistor NM4, are all in the same ratio n. Therefore, the current value of the final low-side drive signal is n*Ib2.

[0085] In this way, by adjusting the ratio of the transistors on the two branches and the reference bias current of the current source IB2, the current value of the high-side drive signal can be further adjusted to achieve a low drive current output.

[0086] Among them, through the circuit design of the above-mentioned high-side drive module 130 and low-side drive module 140, the level conversion module 120 only needs to generate a high-side drive signal and a low-side drive signal with the same signal frequency but opposite phases to achieve the drive of the high-voltage side and the low-voltage side, reducing the circuit requirements for the level conversion module 120.

[0087] The embodiment of the present invention also provides a high-voltage drive circuit, such as Figure 8As shown, it includes an input module 110, a level conversion module 120, a high-side drive module 130, a low-side drive module 140, and an overcurrent detection module 150. Among them, the input module 110 includes a first comparator 111, an overtemperature detection unit 112, and a first logic gate circuit 113. The overcurrent detection module 150 includes a transistor NM0, a second comparator 151, a second logic gate circuit 153, a third comparator 152, a third logic gate circuit 154, and a fourth logic gate circuit 155. The high-side drive module 130 includes: a transistor PM1, a transistor PM2, a transistor PM3, a transistor PM4, a current source IB1, and an ideal diode circuit UD1. The low-side drive module 140 includes: a transistor NM1, a transistor NM2, a transistor NM3, a transistor NM4, and a current source IB2.

[0088] The foregoing are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A high-voltage drive circuit, characterized in that, Comprising: An input module, configured to receive an analog input signal and convert the analog input signal into a digital input signal; A level conversion module, connected to the input module, configured to generate a high-side input signal and a low-side input signal respectively according to the digital input signal; A high-side driving module, connected to the level conversion module, configured to output a high-side driving signal under the excitation of the high-side input signal; A low-side driving module, connected to the level conversion module, configured to output a low-side driving signal under the excitation of the low-side input signal; Wherein, one of the high-side driving module and the low-side driving module is selectively connected to an output pin of the high-voltage driving circuit.

2. The high-voltage drive circuit according to claim 1, wherein The analog input signal includes a first analog signal and a second analog signal, the digital input signal includes a first digital signal, and the input module is further configured to: Detect the module temperatures of the high-side driving module and the low-side driving module; If the voltage difference between the first analog signal and the second analog signal is greater than a first threshold voltage and the module temperature does not exceed a temperature threshold, convert the voltage difference to obtain the first digital signal; The level conversion module is further configured to generate the high-side input signal and the low-side input signal respectively according to the first digital signal.

3. The high-voltage drive circuit according to claim 2, characterized in that, The digital input signal includes a second digital signal, and the input module is further configured to: If the voltage difference is less than a second threshold voltage, or the module temperature exceeds the temperature threshold, convert the voltage difference to obtain the second digital signal; The level conversion module is further configured to stop generating the high-side input signal and the low-side input signal according to the second digital signal.

4. The high-voltage drive circuit according to claim 3, characterized in that The input module includes: A first comparator, with two input terminals of the first comparator respectively receiving the first analog signal and the second analog signal in a one-to-one correspondence, configured to compare the voltage difference with the first threshold voltage and the second threshold voltage respectively, and output a comparison signal; An over-temperature detection unit, configured to detect whether the temperatures of the high-side driving module and the low-side driving module exceed the temperature threshold, and output a temperature detection signal; A first logic gate circuit, connected to the first comparator and the over-temperature detection unit respectively, configured to output the digital input signal according to the comparison signal and the temperature detection signal.

5. The high-voltage drive circuit according to claim 3, wherein The high-voltage driving circuit further includes: An over-current detection module, connected to the input module, the high-side driving module and the low-side driving module respectively, configured to, if receiving the first digital signal and determining that a high-side difference between the high-side driving signal and a high-side voltage threshold is greater than a third threshold voltage, or a low-side difference between the low-side driving signal and a low-side voltage threshold is greater than a fourth threshold voltage, output an over-current detection signal.

6. The high-voltage driving circuit according to claim 5, wherein The over-current detection module is further configured to, if receiving the second digital signal, or determining that the high-side difference between the high-side driving signal and the high-side voltage threshold is less than a fifth threshold voltage, and the low-side difference between the low-side driving signal and the low-side voltage threshold is less than a sixth threshold voltage, stop outputting the over-current detection signal.

7. The high-voltage driving circuit according to claim 5 or 6, characterized in that The over-current detection module includes: Transistor NM0, the first connection terminal of the transistor NM0 is connected to the first power supply terminal, and the second connection terminal of the transistor NM0 is connected to the second power supply terminal; A second comparator, the positive phase terminal of the second comparator is used to receive the high-side voltage threshold, the negative phase terminal of the second comparator is used to receive the high-side drive signal, and the second comparator is used to output a high-side voltage comparison signal according to the high-side drive signal and the high-side voltage threshold; A second logic gate circuit, which is respectively connected to the output terminal of the second comparator and the input module, and is used to output a first logic signal according to the digital input signal and the high-side voltage comparison signal; A third comparator, the positive phase terminal of the third comparator is used to receive the low-side drive signal, the negative phase terminal of the third comparator is used to receive the low-side voltage threshold, and the third comparator is used to output a low-side voltage comparison signal according to the low-side drive signal and the low-side voltage threshold; A third logic gate circuit, which is respectively connected to the output terminal of the third comparator and the input module, and is used to output a second logic signal according to the digital input signal and the low-side voltage comparison signal; A fourth logic gate circuit, which is respectively connected to the second logic gate circuit, the third logic gate circuit and the gate of the transistor NM0, and is used to control the on-off of the transistor NM0 according to the first logic signal and the second logic signal, so as to output or stop outputting the overcurrent detection signal at the first connection terminal of the transistor NM0.

8. The high-voltage driving circuit according to claim 1, characterized in that The high-side drive module includes: transistor PM1, transistor PM2, transistor PM3, transistor PM4 and current source IB1; the control terminals of the transistor PM1 and the transistor PM2 are commonly connected and connected to the level conversion module for receiving the high-side input signal; the first connection terminals of the transistor PM1 and the transistor PM2 are commonly connected for receiving the first high-side power supply voltage; the second connection terminal of the transistor PM1 is connected to the first connection terminal of the transistor PM3; the second connection terminal of the transistor PM2 is connected to the first connection terminal of the transistor PM4; the control terminal and the second connection terminal of the transistor PM3, and the control terminals of the transistor PM4 are commonly connected and connected to the first end of the current source IB1; the second end of the current source IB1 is connected to the second high-side power supply voltage; the second connection terminal of the transistor PM4 is used to output the high-side drive signal.

9. The high-voltage drive circuit according to claim 8, wherein The high-side drive module further includes: An ideal diode circuit, the anode of the ideal diode circuit is connected to the second connection terminal of the transistor PM4, and the cathode of the ideal diode circuit is used to output the high-side drive signal.

10. The high-voltage drive circuit according to claim 1, characterized in that, The low-side driving module includes: a transistor NM1, a transistor NM2, a transistor NM3, a transistor NM4, and a current source IB2; a first end of the current source IB2 is configured to receive a first low-side power supply voltage; a control end and a first connection end of the transistor NM1, a second end of the current source IB2, and a control end of the transistor NM2 are commonly connected; a second connection end of the transistor NM1 is connected to a first connection end of the transistor NM3; a control end of the transistor NM3 and a control end of the transistor NM4 are commonly connected and are connected to the level conversion module for receiving the low-side input signal; a first connection end of the transistor NM2 is configured to output the low-side driving signal; a second connection end of the transistor NM2 is connected to a first connection end of the transistor NM4; a second connection end of the transistor NM3 and a second connection end of the transistor NM4 are commonly connected for receiving a second low-side power supply voltage.

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