Temperature detection circuit

Abstract

The application provides a temperature detection circuit, belonging to the field of integrated circuits, which comprises a first field effect transistor, a second field effect transistor, a third field effect transistor, an operational amplifier, a second triode and a first triode; the sources of the first field effect transistor, the second field effect transistor and the third field effect transistor are respectively connected with a direct current power supply; the gates of the first field effect transistor, the second field effect transistor and the third field effect transistor are respectively connected with a first end of the operational amplifier; the drain of the first field effect transistor, the emitter of the second triode and a second end of the operational amplifier are respectively connected to a first connecting point; the drain of the second field effect transistor, the emitter of the first triode and a third end of the operational amplifier are respectively connected to a second connecting point; the drains of the third field effect transistor are respectively connected with the collectors of the second triode and the first triode and connected to a grounding end. The application realizes the performance improvement of temperature detection sensitivity and precision, and simultaneously realizes the simplification of circuit structure, the reduction of area and the reduction of power consumption.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit design technology, and in particular to a temperature detection circuit. Background Technology

[0002] As the size of integrated circuit manufacturing processes decreases, power consumption and heat generation are gradually becoming limiting factors in deep submicron circuits.

[0003] Traditional CMOS temperature detectors consist of a bandgap reference, a temperature sensing circuit, and a comparator. The bandgap reference (BGR) is transmitted through a positive temperature coefficient voltage ΔV. BE and negative temperature coefficient voltage V BE Different combinations of weighting coefficients are used to achieve a zero-temperature-drift output voltage, while the temperature sensing circuit generally uses a transistor with a ΔV that is proportional to the absolute temperature (PTAT). BE Or V, which is inversely proportional to absolute temperature (CTAT) BE .

[0004] Existing temperature sensing circuits suffer from low temperature sensitivity, poor accuracy, and large area. Summary of the Invention

[0005] This invention provides a temperature detection circuit to address the shortcomings of existing temperature sensing circuits, such as low sensitivity, low accuracy, and large area.

[0006] The present invention provides a temperature detection circuit, comprising: a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, an operational amplifier, a second transistor, and a first transistor;

[0007] The source of the first field-effect transistor, the source of the second field-effect transistor, and the source of the third field-effect transistor are connected to a DC power supply, respectively.

[0008] The gates of the first field-effect transistor, the second field-effect transistor, and the third field-effect transistor are respectively connected to the first terminal of the operational amplifier.

[0009] The drain of the first field-effect transistor, the emitter of the second transistor, and the second terminal of the operational amplifier are respectively connected to the first connection point;

[0010] The drain of the second field-effect transistor, the emitter of the first transistor, and the third terminal of the operational amplifier are respectively connected to the second connection point;

[0011] The drain of the third field-effect transistor is connected to the collector of the second transistor and the collector of the first transistor, respectively, and then connected to the ground terminal.

[0012] The base of the second transistor is connected to the base of the first transistor, and then connected to the ground terminal.

[0013] In some embodiments, a first resistor is provided between the second connection point and the emitter of the first transistor.

[0014] In some embodiments, a second resistor and a third resistor are provided between the drain of the third field-effect transistor and the ground terminal;

[0015] The drain of the third field-effect transistor and the first terminal of the third resistor are respectively connected to the third connection point;

[0016] The second end of the third resistor and the first end of the second resistor are respectively connected to the fourth connection point;

[0017] The second end of the second resistor is connected to the ground terminal.

[0018] In some embodiments, a first comparator is also included;

[0019] The first terminal of the first comparator is connected to the third connection point;

[0020] The second terminal of the first comparator is connected to the first connection point;

[0021] The third terminal of the first comparator outputs the first comparison signal.

[0022] In some embodiments, a second comparator is also included;

[0023] The first terminal of the second comparator is connected to the first connection point;

[0024] The second terminal of the second comparator is connected to the fourth connection point;

[0025] The third terminal of the second comparator outputs the second comparison signal.

[0026] In some embodiments, a fourth field-effect transistor is also included;

[0027] The source of the fourth field-effect transistor is connected to the DC power supply;

[0028] The gate of the fourth field-effect transistor is connected to the first terminal of the operational amplifier;

[0029] The drain of the fourth field-effect transistor is connected to the collector of the second transistor and the collector of the first transistor, and then connected to the ground terminal.

[0030] In some embodiments, a first resistor is provided between the second connection point and the emitter of the first transistor.

[0031] In some embodiments, a third resistor is provided between the drain of the third field-effect transistor and the ground terminal;

[0032] A second resistor is provided between the drain of the fourth field-effect transistor and the ground terminal;

[0033] The drain of the third field-effect transistor and the first terminal of the third resistor are respectively connected to the third connection point;

[0034] The drain of the fourth field-effect transistor and the first terminal of the second resistor are respectively connected to the fifth connection point;

[0035] The second end of the second resistor is connected to the ground terminal;

[0036] The second end of the third resistor is connected to the ground terminal.

[0037] In some embodiments, a first comparator is also included;

[0038] The first terminal of the first comparator is connected to the third connection point;

[0039] The second terminal of the first comparator is connected to the first connection point;

[0040] The third terminal of the first comparator outputs the first comparison signal.

[0041] In some embodiments, a second comparator is also included;

[0042] The first terminal of the second comparator is connected to the first connection point;

[0043] The second terminal of the second comparator is connected to the fifth connection point;

[0044] The third terminal of the second comparator outputs the second comparison signal.

[0045] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0047] Figure 1 This is a block diagram of a traditional CMOS temperature detector;

[0048] Figure 2 This is a typical PTAT temperature sensing circuit diagram;

[0049] Figure 3 This is a typical CTAT temperature sensing circuit diagram;

[0050] Figure 4This is one of the circuit diagrams of the temperature detection circuit provided by the present invention;

[0051] Figure 5 It is the temperature sensing voltage V BE2 V PTATL and V PTATH Curve showing temperature variation and schematic diagram of temperature detection threshold;

[0052] Figure 6 This is the second circuit diagram of the temperature detection circuit provided by the present invention;

[0053] Figure 7 This is the third circuit diagram of the temperature detection circuit provided by the present invention;

[0054] Figure 8 This is the fourth circuit diagram of the temperature detection circuit provided by the present invention. Detailed Implementation

[0055] Figure 1 This is a block diagram of a traditional CMOS temperature detector, which includes a bandgap reference, a temperature sensing circuit, and a comparator. The bandgap reference (BGR) is connected to a positive temperature coefficient voltage ΔV. BE and negative temperature coefficient voltage V BE The output voltage with zero temperature drift can be achieved by combining different weighting coefficients.

[0056] Figure 2 This is a typical PTAT temperature sensing circuit diagram. If this PTAT temperature sensing circuit is used, ΔV BE A small positive temperature coefficient requires increasing the R3 / R1 ratio to achieve greater temperature sensitivity. This increases the area and amplifies errors caused by operational amplifier offset and current mirror mismatch, resulting in a large VPTAT variation range and decreased temperature sensing accuracy. Introducing chopper technology to reduce offset and noise effects would increase circuit complexity and sacrifice area and power consumption.

[0057] Figure 3 This is a typical CTAT temperature sensing circuit diagram. If this CTAT temperature sensing circuit is used, V BE Due to the influence of the process, there are differences between different process corners, resulting in V BE Fluctuations lead to inaccurate temperature detection thresholds. Furthermore, the negative temperature coefficient is fixed at approximately -1.5mV / ℃ and cannot be adjusted or increased.

[0058] Based on the above-mentioned technical problems, this application provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy while reducing the circuit area and power consumption.

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0060] Figure 4 This is one of the circuit diagrams of the temperature detection circuit provided by the present invention, such as... Figure 4 As shown, the temperature detection circuit includes a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, an operational amplifier, a second transistor, and a first transistor;

[0061] The source of the first field-effect transistor, the source of the second field-effect transistor, and the source of the third field-effect transistor are connected to a DC power supply, respectively.

[0062] The gates of the first field-effect transistor, the second field-effect transistor, and the third field-effect transistor are respectively connected to the first terminal of the operational amplifier.

[0063] The drain of the first field-effect transistor, the emitter of the second transistor, and the second terminal of the operational amplifier are respectively connected to the first connection point;

[0064] The drain of the second field-effect transistor, the emitter of the first transistor, and the third terminal of the operational amplifier are respectively connected to the second connection point;

[0065] The drain of the third field-effect transistor is connected to the collector of the second transistor and the collector of the first transistor, respectively, and then connected to the ground terminal.

[0066] The base of the second transistor is connected to the base of the first transistor, and then connected to the ground terminal.

[0067] Specifically, an embodiment of the present invention provides a temperature detection circuit, including a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, an operational amplifier, a second transistor, and a first transistor.

[0068] A field-effect transistor (FET) is a semiconductor device that uses the electric field effect of the input circuit to control the current in the output circuit.

[0069] The operational amplifier forms a negative feedback loop, forcing the positive and negative input terminals to have equal potentials.

[0070] Among them, the PMOS transistor can be a common-source, common-gate structure to improve the power supply rejection ratio of the temperature detection circuit.

[0071] Specifically, through technological means, the area of ​​transistor Q1 is made to be n times that of Q2, for example, 8 times or 16 times the area of ​​transistor Q2, in order to generate ΔV. BE .

[0072] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0073] In some embodiments, a first resistor is provided between the second connection point and the emitter of the first transistor.

[0074] Specifically, such as Figure 4 The resistor R1 shown is the first resistor, used to generate a negative temperature coefficient voltage V through transistors Q1 / Q2 of different areas, R1, an operational amplifier, and a current mirror. BE2 The positive temperature coefficient current I1 is given by the fact that since the PMOS transistors have the same size, the current flowing through them is the same, i.e., I0 = I1 = I2.

[0075] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0076] In some embodiments, a second resistor and a third resistor are provided between the drain of the third field-effect transistor and the ground terminal;

[0077] The drain of the third field-effect transistor and the first terminal of the third resistor are respectively connected to the third connection point;

[0078] The second end of the third resistor and the first end of the second resistor are respectively connected to the fourth connection point;

[0079] The second end of the second resistor is connected to the ground terminal.

[0080] Specifically, R2 and R3 can be designed as adjustable resistors, and the accuracy of the temperature measurement point of the chip circuit can be further improved by fine-tuning the resistors.

[0081] Specifically, the formula for calculating the voltage at the positive temperature coefficient terminal of the high-temperature detection comparator in the temperature detection circuit of the present invention is as follows:

[0082]

[0083] Among them, V PTATH This is the voltage at the positive temperature coefficient terminal of the high-temperature detection comparator. R1 is the first resistor, and R2 is the second resistor. V BE2 V is the emitter voltage of Q2. BE2 V is used to characterize negative temperature coefficient properties.BE1 V is the emitter voltage of Q1. BE1 V is used to characterize the positive temperature coefficient. T The voltage equivalent of temperature is kT / q, where k is the Boltzmann constant, T is the thermodynamic temperature, and q is the electron charge. At room temperature, V... T It equals 0.026V, ln is the natural logarithm function, and n is the ratio of the areas of Q1 and Q2.

[0084] V is achieved at the threshold temperature by adjusting R2. BE2 equals V PTATH .

[0085] Specifically, the formula for calculating the voltage at the positive temperature coefficient end of the low-temperature detection comparator in the temperature detection circuit of the present invention is as follows:

[0086]

[0087] Among them, V PTATL This is the voltage at the positive temperature coefficient terminal of the low-temperature detection comparator. R1 is the first resistor, R2 is the second resistor, and R3 is the third resistor. V BE2 V is the emitter voltage of Q2. BE2 V is used to characterize negative temperature coefficient properties. BE1 V is the emitter voltage of Q1. BE1 V is used to characterize the positive temperature coefficient. T The voltage equivalent of temperature is kT / q, where k is the Boltzmann constant, T is the thermodynamic temperature, and q is the electron charge. At room temperature, V... T It equals 0.026V, ln is the natural logarithm function, and n is the ratio of the areas of Q1 and Q2.

[0088] V is achieved at the threshold temperature by adjusting R3. BE2 equals V PTATL .

[0089] Specifically, the positive temperature coefficient V PTATH Temperature sensitivity is achieved by adjusting the multiple n of Q2 and V. PTATH The resistance value of the branch is achieved.

[0090] Specifically, the positive temperature coefficient current I2 is obtained through a current mirror, and the values ​​of resistances R2 and R3 are calculated based on the high-temperature threshold and low-temperature threshold detected by temperature detection, thus obtaining V. PTATH and V PTATL .

[0091] Specifically, without introducing additional circuitry, the difference between the positive temperature coefficient voltage and the negative temperature coefficient voltage is used simultaneously, and the BGR circuit and the temperature sensing circuit are combined into the same circuit to generate the positive temperature coefficient voltage V corresponding to the high temperature threshold point. PTATH The positive temperature coefficient voltage V corresponding to the low temperature threshold point PTATL Then the positive temperature coefficient voltage V PTATH and positive temperature coefficient voltage V PTATL respectively with negative temperature coefficient V BE The difference is calculated using a comparator to obtain the digital output signals for high and low temperature warnings from the temperature detector.

[0092] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0093] In some embodiments, a first comparator is included;

[0094] The first terminal of the first comparator is connected to the third connection point;

[0095] The second terminal of the first comparator is connected to the first connection point;

[0096] The third terminal of the first comparator outputs the first comparison signal.

[0097] Specifically, the comparator has two analog inputs and a binary output. Its output remains constant as the difference in input voltage increases or decreases. From this perspective, the comparator can also be considered a 1-bit analog-to-digital converter (ADC).

[0098] Specifically, the positive temperature coefficient voltage V corresponding to the low temperature threshold point. PTATL and V BE2 The low temperature warning output signal is obtained by comparing the signals using the first comparator.

[0099] Figure 5 The sensing voltage V BE2 V PTATL and V PTATH The diagram shows the temperature change curve and temperature detection threshold. The solid line represents the center process corner (TT corner), and the dashed line represents the upper right process corner (FF corner). Figure 4 and Figure 5 As shown, in V BE2 When used as the negative terminal of the high-temperature detection hysteresis comparator and the positive terminal of the low-temperature detection hysteresis comparator, V... BE2 Greater than V PTATLThe low-temperature alarm output signal TDLO outputs a high level, generating an alarm. When the ambient temperature exceeds the low-temperature detection threshold temperature, V... BE2 Less than V PTATL When the low temperature alarm output signal TDLO is low, no alarm will be triggered.

[0100] on the contrary, Figure 6 This is a second circuit diagram of the temperature detection circuit provided by the present invention, as shown below. Figure 5 and Figure 6 As shown, in V BE2 When used as the positive terminal of the high-temperature detection hysteresis comparator and the negative terminal of the low-temperature detection hysteresis comparator, V... BE2 Greater than V PTATL The low-temperature alarm output signal TDLO outputs a low level, generating an alarm. When the ambient temperature is higher than the low-temperature detection threshold temperature, V... BE2 Less than V PTATL When the low temperature alarm output signal TDLO is high, no alarm will be triggered.

[0101] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0102] On another aspect, such as Figure 5 As shown, the high temperature threshold voltage point V PTATH and low temperature threshold voltage point V PTATL With ΔV BE Proportional to, negative temperature coefficient V BE With ΔV BE The trend of V changes in accordance with the process angle is consistent, which makes V change with the process angle. BE and V PTATL / V PTATH Although the voltage value changes when the voltage changes in the same direction, the high-temperature threshold temperature and the low-temperature threshold temperature remain almost unchanged. This greatly reduces the temperature detection threshold changes caused by process variations and further improves detection accuracy.

[0103] In some embodiments, a second comparator is also included;

[0104] The first terminal of the second comparator is connected to the first connection point;

[0105] The second terminal of the second comparator is connected to the fourth connection point;

[0106] The third terminal of the second comparator outputs the second comparison signal.

[0107] Specifically, the positive temperature coefficient voltage V corresponding to the high temperature threshold point PTATH and VBE2 The high-temperature warning output signal is obtained by comparing the signals using a second comparator.

[0108] like Figure 4 and Figure 5 As shown, in V BE2 When used as the negative terminal of the high-temperature detection hysteresis comparator and the positive terminal of the low-temperature detection hysteresis comparator, V... BE2 Less than V PTATH The high-temperature alarm output signal TDHO outputs a high level, generating an alarm. When the ambient temperature is below the high-temperature detection threshold temperature, V... BE2 Greater than V PTATH The high temperature alarm output signal TDHO outputs a low level, and no alarm is triggered.

[0109] Conversely, such as Figure 5 and Figure 6 As shown, in V BE2 When used as the positive terminal of the high-temperature detection hysteresis comparator and the negative terminal of the low-temperature detection hysteresis comparator, V... BE2 Less than V PTATH The high-temperature alarm output signal TDHO outputs a low level, generating an alarm. When the ambient temperature is below the high-temperature detection threshold temperature, V... BE2 Greater than V PTATH The high-temperature alarm output signal TDHO outputs a high level, and no alarm is triggered.

[0110] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0111] On another aspect, such as Figure 5 As shown, the high temperature threshold voltage point V PTATH and low temperature threshold voltage point V PTATL With ΔV BE Proportional to, negative temperature coefficient V BE With ΔV BE The trend of V changes in accordance with the process angle is consistent, which makes V change with the process angle. BE and V PTATL / V PTATH Although the voltage value changes when the voltage changes in the same direction, the high-temperature threshold temperature and the low-temperature threshold temperature remain almost unchanged. This greatly reduces the temperature detection threshold changes caused by process variations and further improves detection accuracy. Figure 7 This is the third circuit diagram of the temperature detection circuit provided by the present invention, as shown below. Figure 7 As shown, the temperature detection circuit also includes a fourth field-effect transistor;

[0112] The source of the fourth field-effect transistor is connected to the DC power supply;

[0113] The gate of the fourth field-effect transistor is connected to the first terminal of the operational amplifier;

[0114] The drain of the fourth field-effect transistor is connected to the collector of the second transistor and the collector of the first transistor, and then connected to the ground terminal.

[0115] Specifically, an embodiment of the present invention provides a temperature detection circuit, including a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, a fourth field-effect transistor, an operational amplifier, a second transistor, and a first transistor.

[0116] A field-effect transistor (FET) is a semiconductor device that uses the electric field effect of the input circuit to control the current in the output circuit.

[0117] The operational amplifier forms a negative feedback loop, forcing the positive and negative input terminals to have equal potentials.

[0118] Among them, the PMOS transistor can be a common-source, common-gate structure to improve the power supply rejection ratio of the temperature detection circuit.

[0119] Specifically, through technological means, the area of ​​transistor Q1 is made to be n times that of Q2, for example, 8 times or 16 times the area of ​​transistor Q2, in order to generate ΔV. BE .

[0120] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0121] In some embodiments, a first resistor is provided between the second connection point and the emitter of the first transistor.

[0122] Specifically, such as Figure 7 The resistor shown is the first resistor, used to generate a negative temperature coefficient voltage V through transistors Q1 / Q2 of different areas, R1, an operational amplifier, and a current mirror. BE2 The positive temperature coefficient current I1, where, since the PMOS transistors have the same size, the current flowing through them is the same, i.e., I0 = I1 = I2 = I3.

[0123] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0124] In some embodiments, a third resistor is provided between the drain of the third field-effect transistor and the ground terminal;

[0125] A second resistor is provided between the drain of the fourth field-effect transistor and the ground terminal;

[0126] The drain of the third field-effect transistor and the first terminal of the third resistor are respectively connected to the third connection point;

[0127] The drain of the fourth field-effect transistor and the first terminal of the second resistor are respectively connected to the fifth connection point;

[0128] The second end of the second resistor is connected to the ground terminal;

[0129] The second end of the third resistor is connected to the ground terminal.

[0130] Specifically, R2 and R3 can be designed as adjustable resistors, and the accuracy of the temperature measurement point of the chip circuit can be further improved by fine-tuning the resistors.

[0131] Specifically, optionally, the voltage calculation formula for the positive temperature coefficient terminal of the high-temperature detection comparator in the temperature detection circuit of the present invention is as follows:

[0132]

[0133] Among them, V PTATH This is the voltage at the positive temperature coefficient terminal of the high-temperature detection comparator. R1 is the first resistor, and R2 is the second resistor. V BE2 V is the emitter voltage of Q2. BE2 Used to characterize negative temperature coefficient properties; V BE1 V is the emitter voltage of Q1. BE1 V is used to characterize the positive temperature coefficient. T The voltage equivalent of temperature is kT / q, where k is the Boltzmann constant, T is the thermodynamic temperature, and q is the electron charge. At room temperature, V... T It equals 0.026V, ln is the natural logarithm function, and n is the ratio of the areas of Q1 and Q2.

[0134] V is achieved at the threshold temperature by adjusting R2. BE2 equals V PTATH .

[0135] Specifically, the formula for calculating the voltage at the positive temperature coefficient end of the low-temperature detection comparator in the temperature detection circuit of the present invention is as follows:

[0136]

[0137] Among them, V PTATH This is the voltage at the positive temperature coefficient terminal of the low-temperature detection comparator. R1 is the first resistor, R2 is the second resistor, and R3 is the third resistor. V BE2 V is the emitter voltage of Q2. BE2V is used to characterize negative temperature coefficient properties. BE1 V is the emitter voltage of Q1. BE1 V is used to characterize the positive temperature coefficient. T The voltage equivalent of temperature is kT / q, where k is the Boltzmann constant, T is the thermodynamic temperature, and q is the electron charge. At room temperature, V... T It equals 0.026V, ln is the natural logarithm function, and n is the ratio of the areas of Q1 and Q2.

[0138] V is achieved at the threshold temperature by adjusting R3. BE2 equals V PTATL .

[0139] Specifically, the positive temperature coefficient V PTATH Temperature sensitivity is achieved by adjusting the multiple n of Q2 and V. PTATH The resistance value of the branch is achieved.

[0140] Specifically, the temperature coefficient current can also be implemented by dividing it into two branches, respectively obtaining V. PTATH and V PTATL .

[0141] Specifically, without introducing additional circuitry, the difference between the positive temperature coefficient voltage and the negative temperature coefficient voltage is used simultaneously, and the BGR circuit and the temperature sensing circuit are combined into the same circuit to generate the positive temperature coefficient voltage V corresponding to the high temperature threshold point. PTATH The positive temperature coefficient voltage V corresponding to the low temperature threshold point PTATL Then the positive temperature coefficient voltage V PTATH and positive temperature coefficient voltage V PTATL respectively with negative temperature coefficient V BE The difference is calculated using a comparator to obtain the digital output signals for high and low temperature warnings from the temperature detector.

[0142] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0143] In some embodiments, a first comparator is also included;

[0144] The first terminal of the first comparator is connected to the third connection point;

[0145] The second terminal of the first comparator is connected to the first connection point;

[0146] The third terminal of the first comparator outputs the first comparison signal.

[0147] Specifically, the comparator has two analog inputs and a binary output. Its output remains constant as the difference in input voltage increases or decreases. From this perspective, the comparator can also be considered a 1-bit analog-to-digital converter (ADC).

[0148] Specifically, the positive temperature coefficient voltage V corresponding to the low temperature threshold point. PTATL and V BE2 The low temperature warning output signal is obtained by comparing the signals using the first comparator.

[0149] Figure 5 The sensing voltage V BE2 V PTATL and V PTATH The diagram shows the temperature change curve and temperature detection threshold. The solid line represents the center process corner (TT corner), and the dashed line represents the upper right process corner (FF corner). Figure 7 and Figure 5 As shown, in V BE2 When used as the negative terminal of the high-temperature detection hysteresis comparator and the positive terminal of the low-temperature detection hysteresis comparator, V... BE2 Greater than V PTATL The low-temperature alarm output signal TDLO outputs a high level, generating an alarm. When the ambient temperature exceeds the low-temperature detection threshold temperature, V... BE2 Less than V PTATL When the low temperature alarm output signal TDLO is low, no alarm will be triggered.

[0150] on the contrary, Figure 8 This is the fourth circuit diagram of the temperature detection circuit provided by the present invention, as shown below. Figure 5 and Figure 8 As shown, in V BE2 When used as the positive terminal of the high-temperature detection hysteresis comparator and the negative terminal of the low-temperature detection hysteresis comparator, V... BE2 Greater than V PTATL The low-temperature alarm output signal TDLO outputs a low level, generating an alarm. When the ambient temperature is higher than the low-temperature detection threshold temperature, V... BE2 Less than V PTATL The low-temperature alarm output signal TDLO outputs a high level, and no alarm is triggered. This invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing detection sensitivity and accuracy while reducing circuit area and power consumption.

[0151] On another aspect, such as Figure 5 As shown, the high temperature threshold voltage point V PTATH and low temperature threshold voltage point VPTATL With ΔV BE Proportional to, negative temperature coefficient V BE With ΔV BE The trend of V changes in accordance with the process angle is consistent, which makes V change with the process angle. BE and V PTATL / V PTATH Although the voltage value changes when the voltage changes in the same direction, the high-temperature threshold temperature and the low-temperature threshold temperature remain almost unchanged. This greatly reduces the temperature detection threshold changes caused by process variations and further improves detection accuracy.

[0152] In some embodiments, a second comparator is also included;

[0153] The first terminal of the second comparator is connected to the first connection point;

[0154] The second terminal of the second comparator is connected to the fourth connection point;

[0155] The third terminal of the second comparator outputs the second comparison signal.

[0156] Specifically, the positive temperature coefficient voltage V corresponding to the high temperature threshold point PTATH and V BE2 The high-temperature warning output signal is obtained by comparing the signals using a second comparator.

[0157] like Figure 7 and Figure 5 As shown, in V BE2 When used as the negative terminal of the high-temperature detection hysteresis comparator and the positive terminal of the low-temperature detection hysteresis comparator, V... BE2 Less than V PTATH The high-temperature alarm output signal TDHO outputs a high level, generating an alarm. When the ambient temperature is below the high-temperature detection threshold temperature, V... BE2 Greater than V PTATH The high temperature alarm output signal TDHO outputs a low level, and no alarm is triggered.

[0158] Conversely, such as Figure 5 and Figure 8 As shown, in V BE2 When used as the positive terminal of the high-temperature detection hysteresis comparator and the negative terminal of the low-temperature detection hysteresis comparator, V... BE2 Less than V PTATH The high-temperature alarm output signal TDHO outputs a low level, generating an alarm. When the ambient temperature is below the high-temperature detection threshold temperature, V... BE2 Greater than V PTATH The high-temperature alarm output signal TDHO outputs a high level, and no alarm is triggered.

[0159] The present invention provides a temperature detection circuit that simplifies the temperature detection circuit structure by combining the BGR circuit and the temperature sensing circuit into the same circuit, thereby optimizing the detection sensitivity and accuracy performance, while reducing the circuit area and power consumption.

[0160] On another aspect, such as Figure 5 As shown, the high temperature threshold voltage point V PTATH and low temperature threshold voltage point V PTATL With ΔV BE Proportional to, negative temperature coefficient V BE With ΔV BE The trend of V changes in accordance with the process angle is consistent, which makes V change with the process angle. BE and V PTATL / V PTATH Although the voltage value changes when the voltage changes in the same direction, the high-temperature threshold temperature and the low-temperature threshold temperature remain almost unchanged. This greatly reduces the temperature detection threshold changes caused by process variations and further improves detection accuracy. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A temperature detection circuit, characterized in that, include: First field-effect transistor, second field-effect transistor, third field-effect transistor, operational amplifier, second transistor, and first transistor; The source of the first field-effect transistor, the source of the second field-effect transistor, and the source of the third field-effect transistor are connected to a DC power supply, respectively. The gates of the first field-effect transistor, the second field-effect transistor, and the third field-effect transistor are respectively connected to the first terminal of the operational amplifier. The drain of the first field-effect transistor, the emitter of the second transistor, and the second terminal of the operational amplifier are respectively connected to the first connection point; The drain of the second field-effect transistor, the emitter of the first transistor, and the third terminal of the operational amplifier are respectively connected to the second connection point; The drain of the third field-effect transistor is connected to the collector of the second transistor and the collector of the first transistor, respectively, and then connected to the ground terminal. The base of the second transistor is connected to the base of the first transistor and then connected to the ground terminal; A first resistor is provided between the second connection point and the emitter of the first transistor; A second resistor and a third resistor are provided between the drain of the third field-effect transistor and the ground terminal; The drain of the third field-effect transistor and the first end of the third resistor are respectively connected to the third connection point, thereby generating a voltage at the positive temperature coefficient end of the low-temperature detection comparator at the third connection point. The second end of the third resistor and the first end of the second resistor are respectively connected to the fourth connection point, thereby generating a voltage at the positive temperature coefficient end of the high temperature detection comparator at the fourth connection point. The second end of the second resistor is connected to the ground terminal; The voltage at the positive temperature coefficient end of the low-temperature detection comparator and the voltage at the positive temperature coefficient end of the high-temperature detection comparator have different voltage values, which are used to achieve different temperature detection thresholds respectively. The area of ​​the first transistor is many times larger than the area of ​​the second transistor; The second resistor and the third resistor are adjustable resistors. By adjusting the second resistor, the emitter voltage of the second transistor at the threshold temperature point is equal to the voltage at the positive temperature coefficient terminal of the high temperature detection comparator. By adjusting the third resistor, the emitter voltage of the second transistor at the threshold temperature point is equal to the voltage at the positive temperature coefficient terminal of the low temperature detection comparator. The emitter voltage of the second transistor, the voltage at the positive temperature coefficient end of the high-temperature detection comparator, and the voltage at the positive temperature coefficient end of the low-temperature detection comparator change in the same direction with the process angle.

2. The temperature detection circuit according to claim 1, characterized in that, It also includes a first comparator; The first terminal of the first comparator is connected to the third connection point; The second terminal of the first comparator is connected to the first connection point; The third terminal of the first comparator outputs the first comparison signal.

3. The temperature detection circuit according to claim 1, characterized in that, It also includes a second comparator; The first terminal of the second comparator is connected to the first connection point; The second terminal of the second comparator is connected to the fourth connection point; The third terminal of the second comparator outputs the second comparison signal.

4. The temperature detection circuit according to claim 1, characterized in that, It also includes the fourth field-effect transistor; The source of the fourth field-effect transistor is connected to the DC power supply; The gate of the fourth field-effect transistor is connected to the first terminal of the operational amplifier; The drain of the fourth field-effect transistor is connected to the collector of the second transistor and the collector of the first transistor, and then connected to the ground terminal.

5. The temperature detection circuit according to claim 4, characterized in that, A second resistor is provided between the drain of the fourth field-effect transistor and the ground terminal; The drain of the fourth field-effect transistor and the first terminal of the second resistor are respectively connected to the fifth connection point; The second end of the third resistor is connected to the ground terminal.

6. The temperature detection circuit according to claim 5, characterized in that, It also includes a first comparator; The first terminal of the first comparator is connected to the third connection point; The second terminal of the first comparator is connected to the first connection point; The third terminal of the first comparator outputs the first comparison signal.

7. The temperature detection circuit according to claim 5, characterized in that, It also includes a second comparator; The first terminal of the second comparator is connected to the first connection point; The second terminal of the second comparator is connected to the fifth connection point; The third terminal of the second comparator outputs the second comparison signal.

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