An angle sensor analog voltage output circuit

Abstract

The application discloses an angle sensor analog voltage output circuit, which comprises a power supply module, an analog switch module, a protection module and a load module connected in sequence, wherein the output end of the protection module is connected with the input end of a sampling module, the output end of the sampling module is connected with an adjusting module through a comparison module, and the adjusting module is connected with the analog switch module. The sensor analog voltage output circuit can ensure the accuracy of the analog output voltage and provide strong short-circuit protection and surge protection.

Description

Technical Field

[0001] This invention relates to angle sensors, and more specifically to an angle sensor analog voltage output circuit. Background Technology

[0002] Angle sensors are widely used in industrial control for feedback of speed or position information. Data output typically uses RS485, CAN differential bus interfaces, PWM, ABZ digital interfaces, or analog voltage output. Analog voltage output is relatively simple to process; the receiving end only needs an analog-to-digital converter module to acquire the data. However, in industrial environments, 24V power supplies are common, and angle sensors need to consider fault tolerance after wiring errors. For analog voltage output, for reliability reasons, protection circuitry is required for power supply short-circuit protection, ground short-circuit protection, and surge protection. However, the added protection circuitry involves series resistors and resettable fuses. These series components can cause voltage division, resulting in an actual output voltage lower than the set voltage, affecting the accuracy of the output voltage. Therefore, adding an additional voltage compensation circuit to achieve accurate voltage output is of practical significance. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an analog voltage output circuit for an angle sensor.

[0004] An angle sensor analog voltage output circuit includes a power supply module, an analog switch module, a protection module, and a load module connected in sequence. The output terminal of the protection module is connected to the input terminal of a sampling module. The output terminal of the sampling module is connected to an adjustment module via a comparison module. The adjustment module is connected to the analog switch module. The sampling module samples the analog voltage output by the protection module and outputs a sampling result. The comparison module compares the sampling result with a set value and outputs a comparison result. The adjustment module outputs an adjustment signal to the analog switch module based on the comparison result. The analog switch module adjusts its output analog voltage according to the adjustment signal.

[0005] Optionally, the power module has a storage capacitor for storing sudden changes in electrical energy; the protection module is used to implement power supply short-circuit protection, ground short-circuit protection, and surge protection; the protection module includes a resistor R1, a TVS transient voltage suppressor diode D1, a TVS transient voltage suppressor diode D2, and a resettable fuse R2. Resistor R1 is connected in series on the analog voltage output line, and TVS transient voltage suppressor diodes D1 and D2 are connected between the analog voltage output line and ground. A resettable fuse R2 is installed on the output line between TVS transient voltage suppressor diodes D1 and D2. The operating voltage of transistor 1 is higher than that of the TVS transient suppression diode D2; the analog switch module includes a PMOS transistor M1, the source of which is connected to the power supply module, the drain of which is connected to the protection module as the output terminal, and the gate of which is connected to the output terminal of the adjustment module. The PMOS transistor M1 operates in the variable resistance region; a body diode D3 is connected in anti-parallel between the source and drain of the PMOS transistor M1; the output current of the PMOS transistor M1 changes with the gate voltage; the sampling module includes an amplifier U3, resistors R14, R15, R16, and R17, wherein one end of resistor R17 is connected to the output terminal of the protection module, and the other end is connected to... Connect the positive input terminal of amplifier U3. One end of resistor R16 is connected to the positive input terminal of amplifier U3, and the other end is grounded. Resistor R14 is connected between the output terminal and the inverting input terminal of amplifier U3. One end of resistor R15 is connected to the inverting input terminal of amplifier U3, and the other end is grounded. The comparator module includes amplifier U1, capacitors C1, C4, and C5, and resistors R10, R11, R12, R21, and R22. One end of resistor R10 is connected to the voltage setpoint input terminal, and the other end is connected to the positive input terminal of amplifier U1. Capacitor C4 and resistor R21 are connected in series to the positive input terminal of amplifier U1. Amplifier U... The inverting input terminal of amplifier U1 is connected to the output terminal of amplifier U3 through resistor R11. Resistor R12 and capacitor C1 are connected in series and then connected across the output terminal and inverting input terminal of amplifier U1. The inverting input terminal of amplifier U1 is also connected to the output terminal of the protection module through resistor R22 and capacitor C5. The adjustment module includes transistor Q5. The base of transistor Q5 is connected to the output terminal of the comparator module through resistor R4. Resistor R4 is connected to the base bias power supply V7 through resistor R7. One path of the collector of transistor Q5 is connected to the gate of PMOS transistor M1, and the other path is connected to the power supply module through resistor R6. The emitter of transistor Q5 is grounded through resistor R3.

[0006] The beneficial effects of this invention are: the analog voltage output circuit of this invention can accurately follow the set voltage. The sensor analog voltage output circuit can ensure the accuracy of the analog output voltage while providing strong protection against power supply short circuits, ground short circuits, and surges, exhibiting high reliability and practicality. Attached Figure Description

[0007] Figure 1 This is the circuit schematic diagram of the present invention; Figure 2 This is the circuit diagram of the present invention; Figure 3 This is the dynamically changing output waveform of the circuit of this invention, Vset. Figure 4 The output waveform of Vout when Vset is a static voltage of 0.5V in the circuit design of this invention; Figure 5 The output waveform of Vout when Vset is a static voltage of 2.5V in the circuit design of this invention; Figure 6 The output waveform of Vout is shown when Vset is a static voltage of 4.5V in the circuit design of this invention. Detailed Implementation

[0008] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that the above and other objects, features, and advantages of the present invention will become clearer. In all the drawings, the same reference numerals indicate the same parts. The drawings are not intentionally drawn to scale; the focus is on illustrating the main points of the invention.

[0009] like Figure 1 As shown, the angle sensor analog voltage output circuit of the present invention includes a power supply module, an analog switch module, a protection module and a load module connected in sequence. The output terminal of the protection module is connected to the input terminal of the sampling module. The output terminal of the sampling module is connected to the adjustment module through the comparison module. The adjustment module is connected to the analog switch module.

[0010] The power supply module provides power to the circuit and may have a storage capacitor to store sudden changes in electrical energy. The analog switch module outputs an analog voltage according to the adjustment instructions from the adjustment module. The protection module implements output protection, such as power supply short-circuit protection, ground short-circuit protection, and surge protection. The sampling module samples the output analog voltage and sends the sampling result to the comparison module. The comparison module compares the sampling result with a set value and outputs the comparison result to the adjustment module. The adjustment module adjusts the analog switch module based on the comparison result, such as adjusting the opening degree (conduction) of the analog switch module, thereby adjusting the magnitude of the output analog voltage.

[0011] See Figure 2 Next, we will provide a more detailed introduction to the specific structure and function of each module.

[0012] Analog switch module

[0013] The analog switch module is connected between the power supply module and the protection module. The analog switch module includes an analog switch that outputs an analog voltage. The analog switch can adjust the magnitude of the output analog voltage according to the adjustment signal from the adjustment module.

[0014] exist Figure 2 The analog switch is a PMOS transistor M1. The source of PMOS transistor M1 is connected to the power supply module, the drain is connected to the protection module as the output terminal, and the gate is connected to the output terminal of the regulation module. A body diode D3 is connected in anti-parallel between the source and drain of PMOS transistor M1. PMOS transistor M1 operates in the variable resistance region. In the variable resistance region, the output current of PMOS transistor M1 changes with the gate voltage. Its current magnitude is inversely proportional to the gate voltage; that is, a decrease in gate voltage increases the drain output current, and vice versa.

[0015] It should be noted that although Figure 2 The example provided only illustrates a PMOS transistor, but those skilled in the art will understand that other types of semiconductor devices can be used instead of PMOS transistors. For example, bipolar transistors or N-MOS transistors. Furthermore, logic circuits combining such semiconductor devices can be used as the modules described above.

[0016] The aforementioned transistors can be of various types. For example, thin-film transistors (TFTs) comprising non-single-crystal semiconductor films can be used, such as amorphous silicon, polycrystalline silicon, and microcrystalline silicon. Transistors comprising compound semiconductors or oxide semiconductors, and thin-film transistors obtained by thinning such compound semiconductors or oxide semiconductors, such as ZnO, a-InGaZnO, SiGe, GaAs, IZO, ITO (indium tin oxide), or SnO, can also be used.

[0017] While all of the aforementioned transistors can be used in this invention, the unique advantages of MOS transistors in terms of power consumption are self-evident. The MOS transistor can be any type of MOS transistor, or a bipolar transistor, Bi-CMOS, or a combination thereof. Furthermore, MOS transistors can be formed using semiconductor substrates, SOI substrates, etc. The aforementioned MOS transistor is a module having at least three terminals: gate, drain, and source. The transistor has a channel region between the drain and source regions, through which current can flow.

[0018] Protection module

[0019] The protection module is used to protect the analog voltage output, including power supply short-circuit protection, ground short-circuit protection, and surge protection. The protection module includes a resistor R1, a TVS transient voltage suppressor diode D1, a TVS transient voltage suppressor diode D2, and a resettable fuse R2. Resistor R1 is connected in series on the analog voltage output line, while TVS transient voltage suppressor diodes D1 and D2 are connected between the analog voltage output line and ground. A resettable fuse R2 is installed on the output line between TVS transient voltage suppressor diodes D1 and D2. The operating voltage of D1 is higher than that of D2.

[0020] The following is combined Figure 2 Analyze each situation in detail.

[0021] Power supply short circuit. Because industrial environments often have various voltage levels, such as 24V, 36V, and 48V, incorrect operation or wiring can lead to the sensor's analog voltage output being incorrectly connected to these power supplies. This incorrect connection is commonly referred to as a power supply short circuit. Without protective measures, a power supply short circuit can damage the angle sensor.

[0022] In this invention, when the 24V power supply is short-circuited, D1 will not operate because the operating voltage of D1 is not reached. D2 is a secondary protection device with a relatively low operating voltage. At this time, a clamping action will occur, and the voltage difference will be applied to R2 (self-resetting fuse). The current will change suddenly, and R2 will be disconnected. At the same time, the clamping voltage of D2 will charge the power supply capacitor through the current limiting resistors R1 and D3, and the circuit will play a protective role.

[0023] Short-circuited to ground. When short-circuited to ground, the voltage output terminal is directly connected to ground. At this time, neither D1 nor D2 will activate. The voltage difference is applied to R2 (resetting fuse). Due to the sudden change in current, R2 disconnects, and the circuit provides protection.

[0024] Surge protection. Due to the relatively high surge voltage, reaching the operating voltage of D1, D1 trips, and most of the energy is discharged through D1. Since the clamping voltage exceeds the operating voltage of D2, D2 trips, and the voltage difference is applied to R2 (resetting fuse). The current changes abruptly, and R2 disconnects. At the same time, the clamping voltage of D2 charges the power supply capacitor through the current limiting resistors R1 and D3, and the circuit plays a protective role.

[0025] Sampling module

[0026] The input terminal of the sampling module is connected to the output terminal of the protection module. The sampling module is used to sample the output analog voltage and output the sampling result.

[0027] The sampling module includes amplifier U3 and resistors R14, R15, R16, and R17. U3, R14, R15, R16, and R17 form a voltage divider amplifier circuit. One end of resistor R17 is connected to the output of the protection module, and the other end is connected to the positive input of amplifier U3. One end of resistor R16 is connected to the positive input of amplifier U3, and the other end is grounded. Thus, resistors R17 and R16 form a series voltage divider circuit. Resistor R14 is connected across the output and inverting input of amplifier U3. One end of resistor R15 is connected to the inverting input of amplifier U3, and the other end is grounded. The output analog voltage, after passing through the voltage divider circuit, is amplified by operational amplifier U1, thereby achieving sampling of the output voltage.

[0028] Comparison module

[0029] The comparison module compares the sampled result with the set value and outputs the comparison result to the adjustment module. The comparison module includes amplifier U1, capacitors C1, C4, and C5, and resistors R10, R11, R12, R21, and R22. U1, C1, C4, C5, R10, R11, R12, R21, and R22 form a comparison circuit with feedback and lead phase compensation.

[0030] One end of resistor R10 is connected to the voltage setting input terminal, and the other end is connected to the positive input terminal of amplifier U1. Capacitor C4 is connected in series with resistor R21 and then connected to the positive input terminal of amplifier U1. The inverting input terminal of amplifier U1 is connected to the output terminal of amplifier U3 through resistor R11. Resistor R12 is connected in series with capacitor C1 and then bridged between the output terminal and the inverting input terminal of amplifier U1. The inverting input terminal of amplifier U1 is also connected to the output terminal of the protection module through resistor R22 and capacitor C5.

[0031] Adjustment module

[0032] The adjustment module outputs an adjustment signal to the analog switch module based on the comparison result of the comparison module, so as to adjust the magnitude of the analog voltage output by the analog switch module.

[0033] The adjustment module includes transistor Q5. The base of transistor Q5 is connected to the output of the comparator module (connected to the output of amplifier U1) via resistor R4. Resistor R4 is connected to the base bias power supply V7 via resistor R7. The base bias power supply V7 provides a reference operating voltage for transistor Q5, thereby speeding up the response time of transistor Q5. One collector of transistor Q5 is connected to the gate of PMOS transistor M1, and the other is connected to the power supply module via resistor R6. The emitter of transistor Q5 is grounded via resistor R3.

[0034] The above is a detailed description of the structure and composition of each module involved in this invention. The following will also incorporate... Figure 1 and Figure 2 The working process of the analog voltage output circuit of the present invention is described in detail.

[0035] In order to achieve accurate voltage output while adding protection circuitry, the present invention does not output the analog voltage directly from the operational amplifier. Instead, the voltage is output from the power supply through a MOSFET (analog switch module) and a protection device (protection module). The actual output voltage is divided, amplified, and negatively fed back, compared with the set output voltage, and then the MOSFET is linearly controlled to turn on, thereby making the actual output voltage accurately follow the set voltage.

[0036] When given Vset ( Figure 2 After the output of power supply V6 is given, if Vout is smaller than Vset, the sampling module samples it and compares it with Vset. This causes U1 output to increase, Q5 base current to increase, Q5 collector current to increase, R6 voltage difference to increase, M1 gate-source voltage to increase, load current to increase, and Vout voltage to increase, ultimately achieving a dynamic equality between Vout and Vset. Conversely, if Vout is larger than Vset after Vset is given, the sampling module compares it with Vset. This causes U1 output to decrease, Q5 base current to decrease, Q5 collector current to decrease, R6 voltage difference to decrease, M1 gate-source voltage to decrease, load current to decrease, and Vout voltage to decrease, ultimately achieving a dynamic equality between Vout and Vset.

[0037] The analog voltage output circuit of this invention was simulated and tested. Figures 3 to 6 The results are from the test. Figure 3 Vset is used for testing; it is a triangular wave with a frequency of 0.5Hz, a minimum level of 0.5V, and a maximum level of 4.5V. Vout is the actual output analog voltage. Vpw is the power supply voltage. RL and CL are the load resistor and load capacitor of the analog voltage acquisition terminal. M1 is a MOSFET with linear control turn-on, D3 is its body diode, and Q5, R3, R4, R6, and R7 form the MOSFET driver circuit. R1, D2, R2, and D1 are surge protection devices for short circuit to ground, short circuit to power supply, and surge protection. R2 is used to simulate a resettable fuse. U3, R14, R15, R16, and R17 form a voltage divider amplifier circuit, and U1, C1, C4, C5, R10, R11, R12, R21, and R22 form a comparator circuit with feedback and lead phase compensation.

[0038] The output voltage deviation between the analog voltage output circuit and the direct operational amplifier output of this invention is as follows:

[0039] As can be seen from the above description, the analog voltage output circuit of this invention can accurately follow the set voltage. The sensor analog voltage output circuit, while ensuring the accuracy of the analog output voltage, provides strong protection against power supply short circuits, ground short circuits, and surges, exhibiting high reliability and practicality.

[0040] Many specific details have been set forth in the foregoing description to provide a thorough understanding of the present invention. However, the above description is merely a preferred embodiment of the present invention, and the present invention can be implemented in many other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed above. Furthermore, any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, using the methods and techniques disclosed above, without departing from the scope of the present invention. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. An angle sensor analog voltage output circuit, characterized in that, The system includes a power supply module, an analog switch module, a protection module, and a load module connected in sequence. The output of the protection module is connected to the input of the sampling module. The output of the sampling module is connected to an adjustment module via a comparison module. The adjustment module is connected to the analog switch module. The power module has a storage capacitor for storing sudden changes in electrical energy; The protection module is used to implement power supply short-circuit protection, ground short-circuit protection, and surge protection. It includes a resistor R1, a TVS transient voltage suppressor diode D1, a TVS transient voltage suppressor diode D2, and a resettable fuse R2. The resistor R1 is connected in series with the analog voltage output line. The TVS transient voltage suppressor diodes D1 and D2 are connected between the analog voltage output line and ground. A resettable fuse R2 is provided on the output line between the TVS transient voltage suppressor diodes D1 and D2. The operating voltage of the TVS transient voltage suppressor diode D1 is higher than that of the TVS transient voltage suppressor diode D2. When the analog voltage output terminal of the sensor is mistakenly short-circuited to a power supply of various voltage levels in the industrial field, the TVS transient voltage suppressor diode D1 will not trip because its operating voltage has not been reached. The TVS transient voltage suppressor diode D2 is a secondary protection diode with a relatively low operating voltage. At this time, a clamping action will occur, and the voltage difference will be applied to the resettable fuse R2. The current will change suddenly, and the resettable fuse R2 will open. At the same time, the clamping voltage of the TVS transient voltage suppressor diode D2 will charge the power supply capacitor through the current limiting resistor R1 and the anti-parallel diode D3, thus providing protection for the circuit. When shorted to ground, the voltage output terminal is directly connected to ground. At this time, neither TVS transient suppression diodes D1 nor D2 will operate. The voltage difference is applied to the resettable fuse R2. The current changes suddenly, and the resettable fuse R2 opens, thus protecting the circuit. Surge protection is provided because the surge voltage is relatively high, reaching the operating voltage of the TVS transient voltage suppressor diode D1. When the TVS transient voltage suppressor diode D1 operates, most of the energy is discharged through the TVS transient voltage suppressor diode D1. Since the clamping voltage exceeds the operating voltage of the TVS transient voltage suppressor diode D2, the TVS transient voltage suppressor diode D2 operates. The voltage difference is applied to the resettable fuse R2, causing a sudden change in current. The resettable fuse R2 opens. At the same time, the clamping voltage of the TVS transient voltage suppressor diode D2 charges the power supply capacitor through the current limiting resistor R1 and the anti-parallel diode D3. The circuit thus provides protection. The sampling module is used to sample the analog voltage output by the protection module and output the sampling result, including amplifier U3, resistors R14, R15, R16 and R17. One end of resistor R17 is connected to the output terminal of the protection module and the other end is connected to the positive input terminal of amplifier U3. One end of resistor R16 is connected to the positive input terminal of amplifier U3 and the other end is grounded. Resistor R14 is connected across the output terminal and the inverting input terminal of amplifier U3. One end of resistor R15 is connected to the inverting input terminal of amplifier U3 and the other end is grounded. The comparison module is used to compare the sampling result with the set value and output the comparison result. It includes amplifier U1, capacitors C1, C4, and C5, and resistors R10, R11, R12, R21, and R22. One end of resistor R10 is connected to the voltage set value input terminal, and the other end is connected to the positive input terminal of amplifier U1. Capacitor C4 is connected to the positive input terminal of amplifier U1 in series with resistor R21. The inverting input terminal of amplifier U1 is connected to the output terminal of amplifier U3 through resistor R11. Resistor R12 is connected to capacitor C1 in series and is connected across the output terminal and the inverting input terminal of amplifier U1. The inverting input terminal of amplifier U1 is also connected to the output terminal of the protection module through resistor R22 and capacitor C5. The adjustment module outputs an adjustment signal to the analog switch module based on the comparison result. This module includes a transistor Q5. The base of transistor Q5 is connected to the output of the comparison module via resistor R4. Resistor R4 is connected to the base bias power supply V7 via resistor R7. One collector of transistor Q5 is connected to the gate of PMOS transistor M1, and the other is connected to the power supply module via resistor R6. The emitter of transistor Q5 is grounded via resistor R3. The analog switch module adjusts its output analog voltage according to the adjustment signal. It includes a PMOS transistor M1, the source of which is connected to the power supply module, the drain of which is connected to the protection module as the output terminal, and the gate of which is connected to the output terminal of the adjustment module. The PMOS transistor M1 operates in the variable resistance region. When Vset is given, if Vout is smaller than Vset, after sampling by the sampling module and comparison by the comparison module, the output of amplifier U1 increases, the base current of transistor Q5 increases, the collector current of transistor Q5 increases, the voltage difference of resistor R6 increases, the gate-source voltage of PMOS transistor M1 increases, the load current increases, and the Vout voltage increases, eventually reaching the condition that Vout and Vset are dynamically equal. When Vset is given, if Vout is larger than Vset, after sampling and comparison with Vset, the output of amplifier U1 decreases, the base current of transistor Q5 decreases, the collector current of transistor Q5 decreases, the voltage difference of resistor R6 decreases, the gate-source voltage of PMOS transistor M1 decreases, the load current decreases, and the Vout voltage decreases, eventually reaching the condition that Vout and Vset are dynamically equal.

2. The voltage output circuit according to claim 1, characterized in that, A body diode D3 is connected in antiparallel between the source and drain of the PMOS transistor M1.

3. The voltage output circuit according to claim 1, characterized in that, The output current of the PMOS transistor M1 changes with the gate voltage.

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