Over-temperature protection ADC (Analog to Digital Converter) circuit with rising and falling threshold values

Abstract

The invention relates to an over-temperature protection ADC (Analog to Digital Converter) circuit with rising and falling threshold values, which comprises a bias module, a sampling voltage generation module, a reference voltage generation module, a comparator, a Schmitt circuit for generating the rising threshold value and the falling threshold value, and an over-temperature protection circuit, the over-temperature protection circuit comprises a trigger MOS tube M37 connected with the ADC circuit and a cascade driver connected with the Schmitt circuit and the trigger MOS tube M37 at the same time. When the temperature of the circuit exceeds a rising threshold value or is lower than a falling threshold value, the cascade driver controls and triggers the MOS tube M37 to change the conduction state of the MOS tube M37 so as to realize the over-temperature protection operation of the ADC circuit; and when the temperature of the circuit is recovered to a normal range, the cascade driver controls and triggers the MOS tube M37 to recover to an initial conduction state or a predetermined conduction working state, so that the ADC circuit recovers to work normally. According to the invention, electronic components in the ADC circuit can be effectively prevented from being damaged due to overheating, so that the reliability of the ADC circuit is improved and the service life of the ADC circuit is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of analog-to-digital converters, and in particular relates to an ADC circuit with rising and falling threshold over-temperature protection. Background Art

[0002] With the rapid development of modern electronic technology, analog-to-digital converters (ADCs) play a vital role in many electronic systems. ADCs are responsible for accurately converting analog signals in the real world into digital signals so that subsequent digital circuits can process, store and transmit them. They are widely used in many fields such as communications, medical treatment, industrial control, aerospace, etc.

[0003] However, as a complex semiconductor device, the performance of ADC is significantly dependent on the ambient temperature. In actual operation, excessively high temperatures may cause performance degradation, parameter drift, or even permanent damage to the internal circuit. Excessively high temperatures can also affect the accuracy, linearity, and stability of the ADC, causing large errors in the conversion results, thus affecting the reliability of the entire electronic system.

[0004] Therefore, the present invention provides an ADC circuit with rising and falling threshold over-temperature protection to solve the above technical problems. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide an ADC circuit with over-temperature protection with rising and falling thresholds, which has an over-temperature protection function and can effectively prevent electronic components in the ADC circuit from being damaged due to overheating, thereby improving the reliability and service life of the ADC circuit.

[0006] The present invention provides an ADC circuit with rising and falling threshold over-temperature protection, which comprises:

[0007] A bias module, used to generate a stable bias current and bias voltage;

[0008] A sampling voltage generating module, connected to the bias module, and used for converting the bias current generated by the bias module into a sampling voltage signal;

[0009] A reference voltage generating module, which is used to generate a reference voltage signal;

[0010] a comparator, connected to the sampling voltage generating module and the reference voltage generating module at the same time, for comparing the sampling voltage signal with the reference voltage signal and outputting a comparison result signal;

[0011] A Schmitt circuit connected to the comparator, configured to receive the comparison result signal and perform signal processing on the comparison result signal to generate a rising threshold and a falling threshold for preventing thermal oscillation;

[0012] An over-temperature protection circuit comprises a trigger MOS tube M37 connected to an ADC circuit and a cascade driver connected to both the Schmidt circuit and the trigger MOS tube M37; when the circuit temperature exceeds the rising threshold or is lower than the falling threshold, the cascade driver controls the trigger MOS tube M37 to change its own conduction state to implement over-temperature protection operation for the ADC circuit; when the circuit temperature returns to a normal range, the cascade driver controls the trigger MOS tube M37 to return to an initial conduction state or a predetermined conduction working state to enable the ADC circuit to resume normal operation.

[0013] Preferably, the bias module adopts a current mirror structure, and the current mirror structure includes a first current mirror structure and a second current mirror structure; the first current mirror structure is composed of transistors M1-M8 connected, and the second current mirror structure is composed of transistors M20-M23 connected.

[0014] Preferably, the reference voltage generating module comprises a transistor Q1 and a first RC filter; the sampling voltage generating module comprises a resistor R3 and a second RC filter; the comparator is composed of transistors M9-M17 connected together; the transistor Q1 is used to generate the reference voltage signal, and the first RC filter is simultaneously connected to the collector of the transistor Q1, the emitter of the transistor Q1 and the gate of the transistor M10, for filtering the reference voltage signal and transmitting the filtered reference voltage signal to the transistor M10; the resistor R3 is connected to the second current mirror structure, for converting the bias current into the sampling voltage signal, and the second RC filter is simultaneously connected to the resistor R3 and the gate of the transistor M11, for filtering the sampling voltage signal and transmitting the filtered sampling voltage signal to the transistor M11.

[0015] Preferably, the Schmitt circuit is composed of transistors M25-M30 connected, the gate of the transistor M26 is connected to the gate of the transistor M27 to form a first connection terminal, the drain of the transistor M11 is connected to the drain of the transistor M15 to form a second connection terminal, and the first connection terminal is connected to the second connection terminal to establish a specific electrical connection relationship between the Schmitt circuit and the comparator.

[0016] Preferably, the gate of the transistor M29 is connected to the gate of the transistor M30 to form a third connection terminal; the cascade driver is composed of transistors M31-M36, and the gate of the transistor M31 is connected to the gate of the transistor M32 to form a fourth connection terminal, and the third connection terminal is connected to the fourth connection terminal, so that a specific electrical connection relationship is established between the Schmidt circuit and the cascade driver; the drain of the transistor M35 is connected to the drain of the transistor M36 and then connected to the gate of the trigger MOS tube M37.

[0017] Preferably, the first RC filter is composed of a resistor R1 connected to a transistor M18; and the second RC filter is composed of a resistor R2 connected to a transistor M19.

[0018] Compared with the related art, the present invention provides an ADC circuit with rising and falling threshold over-temperature protection, which includes a bias module, a sampling voltage generation module, a reference voltage generation module, a comparator, a Schmidt circuit for generating rising threshold and falling threshold, and an over-temperature protection circuit, wherein the over-temperature protection circuit includes a trigger MOS tube M37 connected to the ADC circuit and a cascade driver connected to the Schmidt circuit and the trigger MOS tube M37 at the same time; when the circuit temperature exceeds the rising threshold or is lower than the falling threshold, the cascade driver controls the trigger MOS tube M37 to change its own conduction state to realize the over-temperature protection operation of the ADC circuit; when the circuit temperature returns to the normal range, the cascade driver controls the trigger MOS tube M37 to return to the initial conduction state or the predetermined conduction working state, so that the ADC circuit returns to normal operation. The above-mentioned structure can not only detect and process the over-temperature situation in time, effectively prevent the electronic components in the ADC circuit from being damaged due to overheating, but also prevent fire or other safety accidents caused by overheating, thereby improving the reliability, service life and safety of the ADC circuit, and can automatically adjust the protection threshold according to the actual working situation to adapt to different temperature environments and working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A structural block diagram of an ADC circuit with rising and falling threshold over-temperature protection according to the present invention;

[0020] Figure 2 The present invention is a circuit diagram of an ADC circuit with rising and falling threshold over-temperature protection. DETAILED DESCRIPTION

[0021] The present invention provides an ADC circuit with rising and falling threshold over-temperature protection, aiming to solve the problems of poor reliability, small adaptability and low safety of the existing ADC circuit.

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Please refer to the attached Figure 1-2 As shown, the present invention provides an ADC circuit with rising and falling threshold over-temperature protection, which includes:

[0024] A bias module 1, used for generating a stable bias current and bias voltage;

[0025] A sampling voltage generating module 2, which is connected to the bias module 1 and is used to convert the bias current generated by the bias module into a sampling voltage signal;

[0026] A reference voltage generating module 3, which is used to generate a reference voltage signal;

[0027] A comparator 4, which is connected to the sampling voltage generating module 2 and the reference voltage generating module 3 at the same time, and is used to compare the sampling voltage signal with the reference voltage signal and output a comparison result signal;

[0028] A Schmitt circuit 5, connected to the comparator 4, for receiving the comparison result signal and performing signal processing on the comparison result signal to generate a rising threshold and a falling threshold for preventing thermal oscillation;

[0029] The over-temperature protection circuit 6 includes a trigger MOS tube M37 connected to the ADC circuit and a cascade driver 61 connected to both the Schmidt circuit 5 and the trigger MOS tube M37; when the circuit temperature exceeds the rising threshold or is lower than the falling threshold, the cascade driver 61 controls the trigger MOS tube M37 to change its own conduction state to implement over-temperature protection operation for the ADC circuit; when the circuit temperature returns to a normal range, the cascade driver 61 controls the trigger MOS tube M37 to return to an initial conduction state or a predetermined conduction working state to enable the ADC circuit to resume normal operation.

[0030] In the above structure, when overheating occurs, a high-level signal is generated, and the high-level signal is transmitted to the trigger MOS tube M37. The trigger MOS tube M37 is turned on due to the increase in voltage, and the resistance signal transmission path is pulled down, and normal operation is restored after the temperature drops. Through the setting of the above structure, not only can the overtemperature situation be detected and processed in time, and the damage of electronic components in the ADC circuit due to overheating can be effectively prevented, but also fire or other safety accidents caused by overheating can be prevented, thereby improving the reliability, service life and safety of the ADC circuit, and the protection threshold can be automatically adjusted according to the actual working situation to adapt to different temperature environments and working conditions.

[0031] In this embodiment, the bias module 1 adopts a current mirror structure, and the current mirror structure includes a first current mirror structure 11 and a second current mirror structure 12; the first current mirror structure 11 is composed of transistors M1-M8 connected, and the second current mirror structure 12 is composed of transistors M20-M23 connected.

[0032] Specifically, the reference voltage generating module 3 includes a transistor Q1 and a first RC filter; the sampling voltage generating module 2 includes a resistor R3 and a second RC filter; the comparator 4 is composed of transistors M9-M17 connected together; the transistor Q1 is used to generate the reference voltage signal, and the first RC filter is simultaneously connected to the collector of the transistor Q1, the emitter of the transistor Q1 and the gate of the transistor M10, and is used to filter the reference voltage signal and transmit the filtered reference voltage signal to the transistor M10; the resistor R3 is connected to the second current mirror structure 12, and is used to convert the bias current into the sampling voltage signal, and the second RC filter is simultaneously connected to the resistor R3 and the gate of the transistor M11, and is used to filter the sampling voltage signal and transmit the filtered sampling voltage signal to the transistor M11.

[0033] In this embodiment, the first RC filter is formed by connecting a resistor R1 and a transistor M18; the second RC filter is formed by connecting a resistor R2 and a transistor M19.

[0034] Furthermore, the Schmitt circuit 5 is composed of transistors M25-M30 connected together, the gate of the transistor M26 is connected to the gate of the transistor M27 to form a first connection terminal, the drain of the transistor M11 is connected to the drain of the transistor M15 to form a second connection terminal, and the first connection terminal is connected to the second connection terminal to establish a specific electrical connection relationship between the Schmitt circuit 5 and the comparator 4.

[0035] Furthermore, the gate of the transistor M29 is connected to the gate of the transistor M30 to form a third connection terminal; the cascade driver 61 is composed of transistors M31-M36, and the gate of the transistor M31 is connected to the gate of the transistor M32 to form a fourth connection terminal, and the third connection terminal is connected to the fourth connection terminal, so that a specific electrical connection relationship is established between the Schmidt circuit 5 and the cascade driver 61; the drain of the transistor M35 is connected to the drain of the transistor M36 and then connected to the gate of the trigger MOS tube M37.

[0036] It should be noted that, in order to facilitate understanding of the technical solution of the present invention, the principle of the above structure is explained below:

[0037] The present invention provides an ADC circuit with rising and falling threshold over-temperature protection. Under normal temperature conditions, it is assumed that the current in the circuit follows the formula I=IPTAT=VTln(n) / R, where VT is the thermal voltage, n is a parameter related to transistor characteristics, and R is a specific resistance value. At this time, the voltage between the base B and the emitter E of the transistor Q1 is VBE0, the temperature coefficient is A, and the initial setting VA>VB, where VA is the reference voltage signal generated by the reference voltage generation module 2, and VB is the sampling voltage signal generated by the sampling voltage generation module 2. In this state, OTP is triggered to a high level, and the transistor M11 is turned on so that the voltage on the resistor R1 is zero, and it is obtained. V A =V BE =V BEO -AT; As the temperature continues to rise, VA decreases due to the negative temperature coefficient of the transistor. When the threshold value of the shutdown temperature is reached, VA = VB, the threshold point Toff can be calculated as: When the temperature continues to rise, VB will be greater than VA, and the output of the comparator 4 is low level. At this time, the transistor M11 is turned off. At this time, the output OTP of the over-temperature protection circuit 6 is low level, so that the whole circuit is in the off state; when the temperature starts to drop, the output OTP of the over-temperature protection circuit 6 is low level at the beginning, the transistor M11 is in the off state, and the whole circuit is also in the off state. At this time, the voltage of VB is: As the temperature continues to drop, VB will gradually decrease and VA will gradually increase. When VA is equal to VB, the circuit will start working again. At this time, the temperature threshold point Ton is: When the temperature drops below Ton, the circuit will resume normal operation. According to the above analysis, the temperature hysteresis △T of the over-temperature protection circuit can be calculated as follows:

[0038] The off temperature Toff can be adjusted by the resistor R2, and the temperature hysteresis ΔT can be adjusted by the resistor R1.

[0039] Compared with the related art, the present invention provides an ADC circuit with rising and falling threshold over-temperature protection, which includes a bias module, a sampling voltage generation module, a reference voltage generation module, a comparator, a Schmidt circuit for generating rising threshold and falling threshold, and an over-temperature protection circuit, wherein the over-temperature protection circuit includes a trigger MOS tube M37 connected to the ADC circuit and a cascade driver connected to the Schmidt circuit and the trigger MOS tube M37 at the same time; when the circuit temperature exceeds the rising threshold or is lower than the falling threshold, the cascade driver controls the trigger MOS tube M37 to change its own conduction state to realize the over-temperature protection operation of the ADC circuit; when the circuit temperature returns to the normal range, the cascade driver controls the trigger MOS tube M37 to return to the initial conduction state or the predetermined conduction working state, so that the ADC circuit returns to normal operation. The above-mentioned structure can not only detect and process the over-temperature situation in time, effectively prevent the electronic components in the ADC circuit from being damaged due to overheating, but also prevent fire or other safety accidents caused by overheating, thereby improving the reliability, service life and safety of the ADC circuit, and can automatically adjust the protection threshold according to the actual working situation to adapt to different temperature environments and working conditions.

[0040] The above-described embodiments should be understood as illustrative rather than limiting the scope of protection of the present invention, which is subject to the claims. For those skilled in the art, some non-essential improvements and adjustments made to the present invention still fall within the scope of protection of the present invention without departing from the essence and scope of the present invention.

Claims

1. An ADC circuit with rising and falling threshold over-temperature protection, characterized in that: The ADC circuit with rising and falling threshold over-temperature protection includes A bias module, used to generate a stable bias current and bias voltage; A sampling voltage generating module, connected to the bias module, and used for converting the bias current generated by the bias module into a sampling voltage signal; A reference voltage generating module, which is used to generate a reference voltage signal; a comparator, connected to the sampling voltage generating module and the reference voltage generating module at the same time, for comparing the sampling voltage signal with the reference voltage signal and outputting a comparison result signal; A Schmitt circuit connected to the comparator, configured to receive the comparison result signal and perform signal processing on the comparison result signal to generate a rising threshold and a falling threshold for preventing thermal oscillation; An over-temperature protection circuit, comprising a trigger MOS tube M37 connected to an ADC circuit and a cascade driver connected to both the Schmidt circuit and the trigger MOS tube M37; when the circuit temperature exceeds the rising threshold or is lower than the falling threshold, the cascade driver controls the trigger MOS tube M37 to change its conduction state, so as to implement an over-temperature protection operation for the ADC circuit; When the circuit temperature returns to a normal range, the cascade driver controls the trigger MOS tube M37 to return to an initial conduction state or a predetermined conduction working state, so that the ADC circuit returns to normal operation.

2. The ADC circuit with rising and falling threshold over-temperature protection according to claim 1, characterized in that: The bias module adopts a current mirror structure, and the current mirror structure includes a first current mirror structure and a second current mirror structure; the first current mirror structure is composed of transistors M1-M8 connected, and the second current mirror structure is composed of transistors M20-M23 connected.

3. The ADC circuit with rising and falling threshold over-temperature protection according to claim 2, characterized in that: The reference voltage generation module includes a transistor Q1 and a first RC filter; the sampling voltage generation module includes a resistor R3 and a second RC filter; the comparator is composed of transistors M9-M17 connected; the transistor Q1 is used to generate the reference voltage signal, and the first RC filter is connected to the collector of the transistor Q1, the emitter of the transistor Q1 and the gate of the transistor M10 at the same time, and is used to filter the reference voltage signal and transmit the reference voltage signal after filtering to the transistor M10; The resistor R3 is connected to the second current mirror structure for converting the bias current into the sampling voltage signal. The second RC filter is simultaneously connected to the resistor R3 and the gate of the transistor M11 for filtering the sampling voltage signal and transmitting the filtered sampling voltage signal to the transistor M11.

4. The ADC circuit with rising and falling threshold over-temperature protection according to claim 3, characterized in that: The Schmitt circuit is composed of transistors M25-M30 connected together, the gate of the transistor M26 is connected to the gate of the transistor M27 to form a first connection terminal, the drain of the transistor M11 is connected to the drain of the transistor M15 to form a second connection terminal, and the first connection terminal is connected to the second connection terminal to establish a specific electrical connection relationship between the Schmitt circuit and the comparator.

5. The ADC circuit with rising and falling threshold over-temperature protection according to claim 4, characterized in that: The gate of the transistor M29 is connected to the gate of the transistor M30 to form a third connection terminal; the cascade driver is composed of transistors M31-M36, and the gate of the transistor M31 is connected to the gate of the transistor M32 to form a fourth connection terminal, and the third connection terminal is connected to the fourth connection terminal, so that a specific electrical connection relationship is established between the Schmidt circuit and the cascade driver; the drain of the transistor M35 is connected to the drain of the transistor M36 and then connected to the gate of the trigger MOS tube M37.

6. The ADC circuit with rising and falling threshold over-temperature protection according to claim 5, characterized in that: The first RC filter is formed by connecting a resistor R1 and a transistor M18; the second RC filter is formed by connecting a resistor R2 and a transistor M19.

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