Temperature detection circuit
By designing a temperature detection circuit including reference circuit, temperature sensor, comparator and logic circuit, the problem of multi-threshold detection in the prior art requires adding multiple comparators, and efficient multi-threshold detection and quantification of temperature information is achieved, saving chip area and power consumption.
Patent Information
- Application Number
- CN202421408029.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-19
- Publication Date
- 2025-04-22
- Estimated Expiration
- 2034-06-19
AI Technical Summary
The existing temperature detection circuit needs to add multiple comparators when setting multiple thresholds, resulting in increased circuit area and power consumption, and is not suitable for temperature intervals where there are more thresholds to be detected.
A temperature detection circuit including a reference circuit, a temperature sensor, a comparator and a logic circuit is designed. The reference voltage is divided into multiple intervals through the reference circuit. The logic circuit dynamically retrieves the temperature interval based on the results of the comparator to realize multi-threshold detection and quantization.
This solution requires only one comparator and logic circuit to realize multi-threshold detection and quantization, greatly saving chip area and power consumption, and is suitable for temperature intervals with more thresholds.
Smart Images
Figure CN222784216U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of integrated circuits, in particular to a temperature detection circuit. Background Art
[0002] As chip integration and operating frequency increase, the heat generated by the chip is also increasing. Long-term operation in a high-temperature environment will seriously affect the reliability of the chip. At the same time, the performance of integrated circuits is very sensitive to temperature changes. In order to compensate for the stability of the circuit or the drift of performance caused by different temperatures, a temperature detection circuit is required to monitor the temperature information of the circuit in real time and perform corresponding processing.
[0003] There are many traditional temperature detection schemes. One is to use a thermistor set outside the chip as a temperature detection sensor to provide temperature data for the circuit. The resistance of the thermistor will change according to the ambient temperature. At the same time, the internal detection circuit makes a judgment on the temperature based on the voltage across the resistor. However, the device cost and area of the thermistor are high, which is not conducive to system integration and low-cost production. The second is to use the positive temperature coefficient voltage generated by the subthreshold MOS tube as the detection unit. This method only requires a small area and power consumption, but its linearity is poor and the detection accuracy is low.
[0004] Another solution is to use the negative temperature characteristic of the base-collector PN junction voltage VBE of the bipolar transistor as a temperature detection sensor. The circuit is simple to implement and can be used as a temperature sensing unit. Figure 1 As shown in the figure, the temperature sensor compares the detected temperature signal with the reference voltage to determine whether the temperature meets the chip working requirements. The solution has a simple structure, but in practical applications, the circuit often needs to make corresponding compensation and adjustments for different temperature ranges, which requires the temperature detection circuit to complete multi-threshold detection to determine the temperature range. As the detection range increases, the circuit area and power consumption will also increase exponentially, so this structure is only suitable for over-temperature protection circuits that require fewer detection thresholds.
[0005] Another solution is to use the positive temperature characteristic of the base-collector voltage difference ΔVBE value of the bipolar transistor working at different current densities as a detection unit, and send the temperature information generated by ΔVBE to the ADC for processing, converting the temperature into a digital signal. This solution solves the problem of low detection accuracy of conventional temperature detection circuits. Figure 2 The figure shows a specific implementation circuit of the scheme, which uses chopping technology and sigma-delta ADC to improve detection accuracy, but its area is large and is not suitable for use as an on-chip auxiliary function circuit.
[0006] Based on this, a new solution is needed. Utility Model Content
[0007] The main purpose of the utility model is to provide a temperature detection circuit to solve the problem that multiple comparators need to be added when setting multiple thresholds in the existing temperature detection circuit.
[0008] To achieve the above-mentioned purpose, the utility model provides a temperature detection circuit, including a reference circuit, a temperature sensor, a comparator and a logic circuit, wherein the input end of the reference circuit is connected to the output end of the logic circuit, the output end of the reference circuit is connected to the positive input end of the comparator, the temperature sensor is connected to the negative input end of the comparator, and the output end of the comparator is connected to the input end of the logic circuit.
[0009] In the temperature detection circuit provided by the utility model, the reference circuit includes a first current source, N resistors, a variable resistor and a data selector, the selection end of the data selector is connected to the output end of the logic circuit, the output end of the data selector is connected to the positive input end of the comparator, the first current source is connected to the first end of the first resistor, the second end of the i-th resistor is connected to the first end of the i+1-th resistor and the i-th input end of the data selector, wherein i is a positive integer greater than or equal to 1 and less than N, the second end of the N-th resistor is connected to the first end of the variable resistor and the N-th input end of the data selector, and the second end of the variable resistor is grounded.
[0010] In the temperature detection circuit provided by the utility model, the temperature sensor includes a second current source and a transistor, the emitter of the transistor is connected to the second current source and the negative input terminal of the comparator, and the collector of the transistor and the base of the transistor are grounded.
[0011] The temperature detection circuit provided by the utility model has the following beneficial effects: the temperature detection circuit provided by the utility model includes a reference circuit, a temperature sensor, a comparator and a logic circuit. The reference circuit divides the reference voltage into multiple intervals, and each interval corresponds to a corresponding temperature range; the logic circuit retrieves the interval where the temperature is located according to the comparison result of the comparator, and converts the temperature into a digital signal, thereby realizing dynamic multi-threshold comparison; compared with the traditional structure, the utility model only needs one comparator and a logic circuit to realize multi-threshold detection and quantification of temperature information, the circuit structure is simple, and the chip area and power consumption are greatly saved. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work:
[0013] Figure 1 Shown is the schematic diagram of a conventional temperature detection circuit;
[0014] Figure 2 The figure shows an existing temperature detection circuit using a chopping technique and a sigma-delta ADC;
[0015] Figure 3 Shown is a circuit diagram of a temperature detection circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION
[0016] In order to facilitate the understanding of the utility model, the utility model will be described more comprehensively with reference to the relevant drawings below. Typical embodiments of the utility model are given in the drawings. However, the utility model can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive.
[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.
[0018] The general idea of the utility model is: in order to solve the problem that multiple comparators need to be added when setting multiple thresholds in the existing temperature detection circuit, the utility model provides a temperature detection circuit, including a reference circuit, a temperature sensor, a comparator and a logic circuit. The reference circuit divides the reference voltage into multiple intervals, and each interval corresponds to a corresponding temperature range; the logic circuit retrieves the interval where the temperature is located according to the comparison result of the comparator, and converts the temperature into a digital signal, thereby realizing dynamic multi-threshold comparison; compared with the traditional structure, the utility model only needs one comparator and a logic circuit to realize multi-threshold detection and quantification of temperature information, and the circuit structure is simple, which greatly saves chip area and power consumption.
[0019] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in combination with the accompanying drawings and specific implementation methods. It should be understood that the embodiments of the utility model and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the utility model and the technical features in the embodiments can be combined with each other.
[0020] Figure 3 FIG. 1 is a schematic diagram of a temperature detection circuit provided by an embodiment of the present utility model. Figure 2As shown, the temperature detection circuit provided by the utility model includes a reference circuit composed of a first current source I1, N resistors R, a variable resistor RTrim and a data selector 110, a temperature sensor composed of a second current source I2 and a triode Q1, a comparator 30 and a logic circuit 20. Among them, the input end of the reference circuit is connected to the output end of the logic circuit, the output end of the reference circuit is connected to the positive input end of the comparator, the temperature sensor is connected to the negative input end of the comparator, and the output end of the comparator is connected to the input end of the logic circuit. The reference circuit selects different reference values Vp as the positive input of the comparator according to the output of the logic circuit; the temperature sensor uses the negative temperature characteristic of the base-collector PN junction voltage Vbe of the bipolar transistor to convert the temperature signal into a voltage signal as the negative input of the comparator; the comparator determines the voltage size of Vp and Vbe at the temperature; the logic circuit controls the data selector of the reference circuit according to the output of the comparator, and uses the dichotomy method to make the value of Vp gradually approach Vbe to obtain temperature information, wherein the logic circuit is a digital circuit on the chip, and the Verilog hardware description language is used to describe its connection relationship and function, thereby generating a netlist.
[0021] Specifically, in an embodiment of the utility model, the reference circuit includes a first current source I1, N resistors R, a variable resistor RTrim and a data selector 110. The data selector includes N input terminals, a selection terminal and an output terminal, the selection terminal is connected to the output terminal of the logic circuit, the output information of the logic circuit is received, and the corresponding input terminal is selected according to the output information; the output terminal is connected to the positive input terminal of the comparator, and the resistor connected to the selected data input terminal is connected to the comparator to generate a reference voltage Vp at the non-inverting input terminal of the comparator. The current source is connected in series with the N resistors R and the variable resistor RTrim in sequence and then grounded, that is, the first current source I1 is connected to the first end of the first resistor, the second end of the i-th resistor is connected to the first end of the i+1-th resistor and the i-th input terminal of the data selector, wherein i is a positive integer greater than or equal to 1 and less than N, the second end of the N-th resistor is connected to the first end of the variable resistor and the N-th input terminal of the data selector, and the second end of the variable resistor is grounded. By connecting a plurality of resistors in series to corresponding ports of the data selector respectively, the reference voltage Vref can be divided into a plurality of intervals, each interval corresponding to a corresponding temperature range, and the variable resistor RTrim is used to adjust the lower limit of the detection threshold.
[0022] Specifically, in an embodiment of the present invention, the temperature sensor includes a second current source and a transistor. The emitter of the transistor is connected to the second current source and the negative input terminal of the comparator. The collector and the base of the transistor are grounded. The second current source I2 and the transistor Q1 constitute a temperature sensor, which uses the negative temperature characteristic of the base-collector PN junction voltage VBE of the bipolar transistor to convert the temperature signal into a voltage signal.
[0023] Specifically, in an embodiment of the present invention, ignoring the voltage drop across the resistor RTrim, initially, N / 2 resistors are connected to the positive input terminal of the comparator through a data selector to set the voltage Vp at the positive input terminal of the comparator to 1 / 2Vref. Then, it is compared with the voltage Vbe at the negative input terminal of the comparator. If Vbe < Vp, it indicates that the temperature measured by the temperature sensor is higher than this threshold, and the comparator outputs 1 to the logic circuit; otherwise, it outputs 0. When the clock clk of the logic circuit arrives, the logic circuit latches this result and adjusts the input port of the data selector according to this result. If the output of the comparator is 1, the voltage Vp at the positive input terminal of the comparator is decreased (for example, adjusted to 1 / 2Vref - 1 / 4Vref), that is, the logic circuit controls the data selector to reduce the resistors connected to the positive input terminal of the comparator. If the output of the comparator is 0, the voltage Vp at the positive input terminal of the comparator is increased (for example, adjusted to 1 / 2Vref + 1 / 4Vref), that is, the data selector increases the resistors connected to the positive input terminal of the comparator. Then, it is compared with Vbe again until the comparison ends. If there are 2n thresholds, only n comparison cycles are required to complete the comparison.
[0024] In the temperature detection circuit provided by the present invention, the logic circuit retrieves the temperature range according to the comparison result of the comparator, then controls the data selector to select the corresponding connection port, connects the resistors that need to be connected in this temperature range to the positive input terminal of the comparator, and then compares with the voltage signal converted by the temperature sensor, thereby realizing dynamic multi-threshold comparison. Compared with the traditional structure, this solution only requires one comparator and a logic circuit to achieve multi-threshold detection and quantization of temperature information. The circuit structure is simple, greatly saving chip area and power consumption.
[0025] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.
[0026] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various utility model aspects, in the above description of the exemplary embodiments of the utility model, the various features of the utility model are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be interpreted as reflecting the following intention: the claimed utility model requires more features than the features explicitly stated in each claim. More specifically, as reflected in the following claims, the utility model aspects are less than all the features of the single embodiment disclosed above. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the utility model.
[0027] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.
[0028] It should be noted that the above embodiments illustrate the utility model rather than limit the utility model, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation to the claims. The word "comprising" does not exclude the existence of elements or steps not listed in the claims. The word "one" or "an" before an element does not exclude the existence of multiple such elements. The utility model can be implemented by means of hardware including several different elements and by means of appropriately programmed computers. In a unit claim that lists several devices, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names.
Claims
1. A temperature detection circuit, characterized in that: The invention comprises a reference circuit, a temperature sensor, a comparator and a logic circuit, wherein the input end of the reference circuit is connected to the output end of the logic circuit, the output end of the reference circuit is connected to the positive input end of the comparator, the temperature sensor is connected to the negative input end of the comparator, and the output end of the comparator is connected to the input end of the logic circuit.
2. The temperature detection circuit according to claim 1, characterized in that: The reference circuit includes a first current source, N resistors, a variable resistor and a data selector, the selection end of the data selector is connected to the output end of the logic circuit, the output end of the data selector is connected to the positive input end of the comparator, the first current source is connected to the first end of the first resistor, the second end of the i-th resistor is connected to the first end of the i+1-th resistor and the i-th input end of the data selector, wherein i is a positive integer greater than or equal to 1 and less than N, the second end of the N-th resistor is connected to the first end of the variable resistor and the N-th input end of the data selector, and the second end of the variable resistor is grounded.
3. The temperature detection circuit according to claim 2, characterized in that: The temperature sensor comprises a second current source and a transistor, the emitter of the transistor is connected to the second current source and the negative input terminal of the comparator, and the collector of the transistor and the base of the transistor are grounded.