Temperature detection circuit and circuit arrangement

Abstract

Temperature detection circuit and circuit device. The temperature detection circuit includes a bias current generation circuit that generates a bias current, a first resistance circuit through which the bias current flows, a second resistance circuit through which a second bias current flows, and a comparison circuit. The comparison circuit compares a first voltage generated by the bias current flowing through the first resistance circuit and a second voltage generated by the bias current flowing through the second resistance circuit, and outputs a comparison result as a detection signal of temperature, the second voltage having a temperature characteristic different from that of the first voltage.

Description

Technical Field

[0001] This invention relates to temperature detection circuits and circuit devices. Background Technology

[0002] Conventionally, in order to achieve a thermal shutdown operation that stops a specified circuit from operating when the internal temperature reaches or exceeds a specified temperature, a temperature detection circuit that compares the specified temperature with the internal temperature is known. Patent Document 1 discloses a method that includes multiple voltage generation circuits and compares the voltages output from each voltage generation circuit.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-009328 Summary of the Invention

[0006] In the method disclosed in Patent Document 1, since the voltage generation circuit includes complex circuit structures such as amplifiers, it is desirable to propose a temperature detection circuit that can detect the desired temperature with a simpler structure.

[0007] One aspect of this disclosure relates to a temperature detection circuit comprising: a bias current generating circuit that generates a first bias current and a second bias current; a first resistor circuit through which the first bias current flows; a second resistor circuit through which the second bias current flows; and a comparison circuit that compares a first voltage and a second voltage and outputs the comparison result as a temperature detection signal, wherein the first voltage is generated by the first bias current flowing through the first resistor circuit, the second voltage is generated by the second bias current flowing through the second resistor circuit, and the voltage-temperature characteristic of the second voltage is different from the first voltage-temperature characteristic of the first voltage.

[0008] Furthermore, other aspects of this disclosure relate to a circuit arrangement comprising the temperature detection circuit and bandgap reference circuit described above, wherein the bias current generation circuit generates the first bias current and the second bias current by mirroring the bias current inside the bandgap reference circuit.

[0009] Furthermore, other aspects of this disclosure relate to a circuit device comprising: the temperature detection circuit described above; and a shutdown circuit that shuts off the circuit device when a detection signal indicating that the temperature has become the temperature of the object being detected is output. Attached Figure Description

[0010] Figure 1This is a diagram illustrating an example of the structure of the temperature detection circuit in this embodiment.

[0011] Figure 2 This is a diagram illustrating an example of the structure of the circuit device in this embodiment.

[0012] Figure 3 This is a diagram illustrating the structure of the first resistor circuit.

[0013] Figure 4 This is a diagram illustrating another structural example of the first resistor circuit.

[0014] Figure 5 This is a diagram illustrating another structural example of the second resistor circuit.

[0015] Figure 6 This is a diagram illustrating an example of the relationship between the temperature characteristics of the first resistor and the temperature characteristics of the second resistor.

[0016] Figure 7 This is another example illustrating the relationship between the temperature characteristics of the first resistor and the temperature characteristics of the second resistor.

[0017] Figure 8 This is a diagram illustrating the relationship between the bandgap reference circuit and the bias current generation circuit.

[0018] Figure 9 This is a diagram illustrating a more detailed structural example of the circuit device according to this embodiment.

[0019] Figure 10 This is a diagram illustrating an example of the layout design of diffusion resistors and polysilicon resistors.

[0020] Label Explanation

[0021] 10…Circuit device; 11…Power receiving circuit; 12…Charging circuit; 13…Charging system control circuit; 15…Shut-off circuit; 20…Power transmission device; 21…Power transmission circuit; 30…Battery; 100…Temperature detection circuit; 101…Bandgap reference circuit; 102…Bias current generation circuit; 110…First resistor circuit; 120…Second resistor circuit; 130…Comparison circuit; BC1…First bias current; BC2…Second bias current; N1, N2, N3, N4, N5, N6, N7, N8, N9, N10, N11, N12, N13, N14, N15, N16, N17, N A, NB, NC, ND, NE, NF, NG, NH, NK… nodes; OP… operational amplifier; R1, R2, R3, R4, R5, R6, R11, R12, R13, R14, R15, R16, R21, R22, R23, R24, R25, R26, R27, R28, R51, R52, R53… resistors; TD… temperature of the object being detected; TE… temperature for testing; TR1, TR2, TR3, TR4, TR5, TR6, TR11, TR12, TR13, TR14, TR15… transistors; V1… first voltage; V2… second voltage. Detailed Implementation

[0022] The preferred embodiments of this disclosure will now be described in detail. Furthermore, the embodiments described below do not unduly limit the content described in the claims, and the structures described in these embodiments are not necessarily all necessary structural elements.

[0023] Figure 1 This is a diagram illustrating an example of the structure of the temperature detection circuit 100 of this embodiment. The temperature detection circuit 100 includes a bias current generation circuit 102, a first resistor circuit 110, a second resistor circuit 120, and a comparison circuit 130.

[0024] The bias current generation circuit 102 generates a first bias current BC1 and a second bias current BC2 based on a specified current source, as detailed later. The specified current source is not particularly limited; for example, it can be a current source with positive or negative temperature characteristics, or a current source without temperature characteristics. The generated first bias current BC1 and second bias current BC2 can have positive or negative temperature characteristics, or they can have no temperature characteristics. Figure 8 As described later, the bias current generation circuit 102 can also generate a first bias current BC1 and a second bias current BC2 by mirroring the internal current of the bandgap reference circuit 101. In this case, the transistors flowing through the internal current of the bandgap reference circuit 101 are components equivalent to a defined current source.

[0025] One input node of the comparator circuit 130 is connected to one end of the first resistor circuit 110 and the output node of the first bias current BC1. Thus, a first voltage V1 generated by the first bias current BC1 flowing through the first resistor circuit 110 is input to one input node of the comparator circuit 130. Furthermore, the temperature characteristic of the first voltage V1 will be referred to below as the first voltage temperature characteristic. The first voltage temperature characteristic is related to the structure of the first resistor circuit 110, as described later.

[0026] Furthermore, another input node of the comparator circuit 130 is connected to one end of the second resistor circuit 120 and the output node of the second bias current BC2. Thus, the second voltage V2 generated by the second bias current BC2 flowing through the second resistor circuit 120 is input to the other input node of the comparator circuit 130. Furthermore, the temperature characteristic of the second voltage V2 will be referred to below as the second voltage temperature characteristic. The second voltage temperature characteristic is related to the structure of the second resistor circuit 120 as described later.

[0027] In addition, although Figure 1 Although not shown in the figure, there may be a predefined line connecting the bias current generation circuit 102 and the bias input node of the comparator circuit 130. The bias current generation circuit 102 may also supply bias current to the comparator circuit 130 through the bias current node.

[0028] The detailed structure of the comparator circuit 130 is a well-known structure and is omitted from the illustration. It compares a first voltage V1 with a first voltage-temperature characteristic and a second voltage V2 with a second voltage-temperature characteristic, and outputs the comparison result as a temperature detection signal. Details will be described later, but in this embodiment, the first and second voltage-temperature characteristics are set to be different. More specifically, the first and second voltage-temperature characteristics are different in that, when the temperature dependence of the voltage is represented by curves for the first voltage V1 and the second voltage V2 respectively, the slopes of the curves are different. Therefore, the curves intersect at a specified temperature.

[0029] For example, a first voltage V1 is input to the negative input node of the comparator circuit 130, and a second voltage V2 is input to the positive input node. In this case, if the temperature around the temperature detection circuit 100 is lower than a predetermined temperature, the first voltage V1 input to the comparator circuit 130 is higher than the second voltage V2, and the comparator circuit 130 outputs, for example, a low-level detection signal. On the other hand, if the temperature around the temperature detection circuit 100 is higher than the predetermined temperature, the second voltage V2 input to the comparator circuit 130 is higher than the first voltage V1, and therefore the comparator circuit 130 outputs, for example, a high-level detection signal. In this case, the change from a low-level detection signal to a high-level detection signal output from the comparator circuit 130 indicates that the temperature has reached the predetermined temperature. Alternatively, the first voltage V1 can be input to the positive input node of the comparator circuit 130, and the second voltage V2 can be input to the negative input node. In this case, when the first voltage V1 input to the comparator circuit 130 is higher than the second voltage V2, a high-level detection signal is output from the comparator circuit 130; when the second voltage V2 input to the comparator circuit 130 is higher than the first voltage V1, a low-level detection signal is output from the comparator circuit 130. Therefore, by setting the desired temperature as the target temperature TD, and by setting the first and second voltage temperature characteristics such that the temperature at the intersection of the first and second voltage temperature characteristics becomes the target temperature TD, the user can construct a temperature detection circuit 100 that indicates when the ambient temperature reaches the target temperature TD.

[0030] Additionally, later on Figure 6 , Figure 7More specific examples of the first voltage temperature characteristic and the second voltage temperature characteristic will be described below, but the examples are not limited thereto, as long as the first voltage temperature characteristic and the second voltage temperature characteristic are different. For example, when the current temperature characteristic of the first bias current BC1 is the same as the current temperature characteristic of the second bias current BC2, the first resistance temperature characteristic, which is the temperature characteristic of the first resistance circuit 110, and the second resistance temperature characteristic, which is the temperature characteristic of the second resistance circuit 120, can be made different using the method described later, thereby making the first voltage temperature characteristic different from the second voltage temperature characteristic. Furthermore, when the current temperature characteristic of the first bias current BC1 is the same as the current temperature characteristic of the second bias current BC2, the temperature at the intersection of the first resistance temperature characteristic and the second resistance temperature characteristic becomes the detected temperature TD. For example, as described later, the bias current generation circuit 102 includes multiple current mirror circuits, and the first bias current BC1 and the second bias current BC2 are generated by mirroring the same current using multiple current mirror circuits, thereby making the current temperature characteristic of the first bias current BC1 the same as the current temperature characteristic of the second bias current BC2. Furthermore, if the temperature characteristics of the first voltage are different from those of the second voltage, the temperature characteristics of the first bias current BC1 and the temperature characteristics of the second bias current BC2 can also be different.

[0031] The temperature detection circuit 100 configured in this way can be applied to, for example... Figure 2 The circuit device 10 shown includes a temperature detection circuit 100 and a shutdown circuit 15. When a detection signal indicating that the temperature has reached the target temperature TD is output, the shutdown circuit 15 shuts down the circuit device 10. For example, although not shown in the figure, the shutdown circuit 15 includes a switch made of a transistor or the like, and controls the on / off state according to the change in the detection signal output from the comparator circuit 130. For example, when the ambient temperature of the temperature detection circuit 100 reaches the target temperature TD, the detection signal output from the comparator circuit 130 changes, and the switch changes from off to on, outputting a predetermined signal indicating that it is set to the shutdown mode to a predetermined circuit (not shown) that is the target of shutdown. Thus, the predetermined circuit is in the shutdown mode during the period of receiving the predetermined signal, for example, it can be in a state where it does not accept desired input.

[0032] Thus, the temperature detection circuit 100 of this embodiment includes: a bias current generation circuit 102 that generates a first bias current BC1 and a second bias current BC2; a first resistor circuit 110 that supplies the flow of the first bias current BC1; a second resistor circuit 120 that supplies the flow of the second bias current BC2; and a comparison circuit 130. The comparison circuit 130 compares the first voltage V1 and the second voltage V2, and outputs the comparison result as a temperature detection signal. The first voltage V1 is generated by the first bias current BC1 flowing through the first resistor circuit 110, and the second voltage V2 is generated by the second bias current BC2 flowing through the second resistor circuit 120. The second voltage temperature characteristic of the second voltage V2 is different from the first voltage temperature characteristic of the first voltage V1.

[0033] Thus, the temperature detection circuit 100 of this embodiment includes a bias current generation circuit 102, a first resistor circuit 110, a second resistor circuit 120, and a comparison circuit 130. Therefore, it is possible to construct a temperature detection circuit 100 that compares a first voltage V1 and a second voltage V2 and outputs the comparison result as a temperature detection signal. Furthermore, the first voltage temperature characteristic, which is the temperature characteristic of the first voltage V1 generated by the first bias current BC1 flowing through the first resistor circuit 110, is different from the second voltage temperature characteristic, which is the temperature characteristic of the second voltage V2 generated by the second bias current BC2 flowing through the second resistor circuit 120. Therefore, it is possible to make the comparison result different at the desired temperature with a simpler circuit structure.

[0034] Furthermore, the method of this embodiment can also be implemented as a circuit device 10. That is, the circuit device 10 of this embodiment includes: the temperature detection circuit 100 described above; and a shutdown circuit 15, which shuts down the circuit device 10 when a detection signal indicating that the temperature is the target temperature TD is output. Thus, a circuit device 10 that shuts down based on the detection signal output from the temperature detection circuit 100 can be constructed to achieve the above-described effects.

[0035] Furthermore, the first voltage-temperature characteristic and the second voltage-temperature characteristic can also intersect at the detected object temperature TD. Therefore, the detection signal output from the comparator circuit 130 can be made different at the detected object temperature TD, thus enabling the construction of a temperature detection circuit 100 that detects the detected object temperature TD.

[0036] Alternatively, the resistance value of the first resistor circuit 110 may have a first resistance temperature characteristic, and the resistance value of the second resistor circuit 120 may have a second resistance temperature characteristic that is different from the first resistance temperature characteristic. This allows the first voltage temperature characteristic and the second voltage temperature characteristic to be different.

[0037] use Figure 3, Figure 4 , Figure 5 The first resistor circuit 110 and the second resistor circuit 120 will be described in more detail below. In the temperature detection circuit 100 of this embodiment, the first resistor circuit 110 is composed of resistors with positive temperature characteristics and resistors with negative temperature characteristics, and the second resistor circuit 120 is composed of resistors with either positive or negative temperature characteristics. Therefore, the temperature characteristics of the first resistor and the second resistor can be different.

[0038] With the first resistor circuit 110 configured in this way, the temperature characteristic of the first resistor is set to be flat. A flat temperature characteristic means that the resistance value of the first resistor circuit 110 remains the same regardless of temperature changes. However, even if the resistance value of the first resistor circuit 110 varies slightly within a desired temperature range, it can still be considered substantially unchanged, and the temperature characteristic can still be considered flat. More specifically, for example, the ratio of resistors with positive temperature characteristics to resistors with negative temperature characteristics is determined in a way that makes the temperature characteristic of the combined resistance of the resistors with positive and negative temperature characteristics in the first resistor circuit 110 flat. Furthermore, since the temperature characteristic of the second resistor only needs to be different from the temperature characteristic of the first resistor, it can be either positive or negative, depending on the appropriate setting. Based on the above, in the temperature detection circuit 100 of this embodiment, the first resistor temperature characteristic is a flat temperature characteristic, and the second resistor temperature characteristic is either positive or negative. Therefore, the intersection point of the first and second resistor temperature characteristics can be easily set. This is because if the resistance value of the first resistor's temperature characteristic can be kept constant, then the desired detection temperature TD can be set simply by adjusting the second resistor's temperature characteristic. Therefore, the detection temperature TD and the test temperature TE (described later) can be easily set.

[0039] Resistors with positive temperature characteristics include, for example, diffusion resistors, which are formed by implanting a high concentration of impurities into a silicon substrate to create a diffusion region, but are not limited to this; other resistors, such as well-well resistors, can also be used. Conversely, resistors with negative temperature characteristics include, for example, polysilicon resistors formed from polysilicon layers, but can also be other types of resistors. Furthermore, polysilicon resistors here are not limited to those formed from pure polysilicon layers, but also include polysilicon resistors doped with P-type impurities and polysilicon resistors doped with N-type impurities; these will be collectively referred to as polysilicon resistors below.

[0040] Furthermore, a diffused resistor is illustrated below as a resistor with a positive temperature resistance characteristic, and a polysilicon resistor is illustrated below as a resistor with a negative temperature resistance characteristic. That is, in the temperature detection circuit 100 of this embodiment, the first resistor circuit 110 is composed of a polysilicon resistor and a diffused resistor, and the second resistor circuit 120 is composed of a polysilicon resistor or a diffused resistor. Thus, a temperature detection circuit 100 comprising a first resistor circuit 110 using a polysilicon resistor and a diffused resistor and a second resistor circuit 120 can be constructed.

[0041] Furthermore, with the first resistor circuit 110 configured in this way, the temperature characteristic of the first resistor is also flat. That is, in the temperature detection circuit 100 of this embodiment, the resistance ratio of the polysilicon resistor to the diffusion resistor in the first resistor circuit 110 is the resistance ratio that makes the temperature characteristic of the first resistor flat. Thus, a first resistor circuit 110 with a flat temperature characteristic can be constructed using a polysilicon resistor with a negative temperature characteristic and a diffusion resistor with a positive temperature characteristic.

[0042] Furthermore, the resistor with a positive temperature characteristic included in the first resistor circuit 110 can be a single diffused resistor or composed of multiple unit resistors. Similarly, the resistor with a negative temperature characteristic included in the first resistor circuit 110 can be a single polysilicon resistor or composed of multiple unit resistors. Figure 3 The specific structure of the first resistor circuit 110 will be explained.

[0043] exist Figure 3 In the circuit, the first resistor circuit 110 includes resistors R1, R2, R3, R4, R5, and R6, which are connected in series. More specifically, one end of resistor R1 is connected to the output node of the first bias current BC1, and the other end is connected to one end of resistor R2. Furthermore, the other end of resistor R2 is connected to one end of resistor R3, the other end of resistor R3 is connected to one end of resistor R4, the other end of resistor R4 is connected to one end of resistor R5, the other end of resistor R5 is connected to one end of resistor R6, and the other end of resistor R6 is connected to a grounded node. The grounded node will be referred to as the ground node below. Additionally, in... Figure 3 The diagram shows the other end of resistor R6 connected to a grounding node, but any node with a constant voltage can be used, and it can also be connected to other nodes. (The following will discuss...) Figure 4 The same applies to the other end of resistor R16.

[0044] exist Figure 3 In the diagram, resistors R1 to R3 are diffusion resistors serving as the first unit resistor, and they are connected in series. Additionally, in... Figure 3In the diagram, resistors R4 to R6 are polysilicon resistors used as the second unit resistors, connected in series. Furthermore, Figure 3 As an example, the number of the first unit is not limited to 3, but can be generalized to n. Similarly, the number of the second unit resistors is not limited to 3, but can be generalized to n. Furthermore, n is an integer greater than or equal to 2. However, regardless of the value of n, the first temperature characteristic is flat.

[0045] In addition, Figure 3 The diagram shows the second resistor unit connected to the grounding node side, but the first resistor unit can also be connected to the grounding node side.

[0046] Furthermore, when the first resistor circuit 110 is configured by using a resistor with positive temperature characteristics as the first unit resistor and a resistor with negative temperature characteristics as the second unit, the combined resistance value of the first resistor circuit 110 can be changed, for example, by switching control. Specifically, the first resistor circuit 110 may also include, for example, […]. Figure 3 The switch shown is A1. In Figure 3 In the circuit shown in A1, a circuit consisting of two resistors R2 and R3 as first unit resistors and two resistors R4 and R5 as second unit resistors is connected in parallel with the switch shown in A1. Furthermore, the number of first and second unit resistors connected in parallel with the switch shown in A1 is not limited to two, and can be generalized to k. k is an integer greater than or equal to 1 and less than n. When the switch shown in A1 is open, the combined resistance of the first resistor circuit 110 is the sum of the resistance values ​​of each of resistors R1 to R6. On the other hand, when the switch shown in A1 is closed, the first bias current BC1 substantially does not flow in the circuit including resistors R2 to R5; therefore, the combined resistance of the first resistor circuit 110 is the sum of the resistance values ​​of resistors R1 and R6. Thus, the combined resistance of the first resistor circuit 110 can be changed by incorporating the switch shown in A1. Furthermore, even when the combined resistance of the first resistor circuit 110 is changed, the temperature characteristic of the first resistor remains flat.

[0047] Figure 3The switch shown in A1 can be used, for example, as a switch for testing the temperature detection circuit 100 in a test mode. Here, "test" refers, for example, to the factory test of the product involving the circuit device 10 containing the temperature detection circuit 100, but it could also be other tests. Furthermore, modes that are not test modes are referred to as normal modes. By changing the resistance value of the combined resistor in the first resistor circuit 110, the position of the intersection point of the first resistance temperature characteristic and the second resistance temperature characteristic changes, thus enabling the first and second resistance temperature characteristics to intersect at two different temperatures. Therefore, a detailed structure will be described later. Figure 6 The explanation is as follows: the higher temperature at the intersection point is set as the target temperature TD, and the lower temperature at the intersection point is set as the test temperature TE, thus the switch shown in A1 is turned on and off. Based on the above, in the temperature detection circuit 100 of this embodiment, the first resistor circuit 110 includes a switch for the test mode, and the switch is connected in parallel with k first unit resistors (k is an integer greater than or equal to 1 and less than n) and k second unit resistors. Therefore, the resistance value of the first resistor circuit 110 can be changed, and thus, in the test mode, the intersection of the first and second resistor temperature characteristics can be achieved at a lower temperature. That is, in the test mode, the intersection of the first and second voltage temperature characteristics can be tested at a lower temperature.

[0048] in addition, Figure 3 The switch shown in A1 is a diagram for ease of explanation. The switching on and off of the switch shown in A1 can also be achieved by using an electrical switching mechanism implemented using a transistor. Figure 4 The switch shown in A2 described later, Figure 5 The switches shown in A11, A12, A13, A14, A15, A16, A17, and A18, described later, are similar. Furthermore, although figures are omitted, the semiconductor package containing the circuit device 10 with the temperature detection circuit 100 includes external terminals for enabling testing devices to switch between normal and test modes. Alternatively, the circuit device 10 containing the temperature detection circuit 100 may also include register circuitry for access by testing devices to switch between normal and test modes.

[0049] Alternatively, the first resistor circuit 110 in this embodiment may also be, for example, as shown in the example... Figure 4 As shown in the example structure. In Figure 4In the circuit, the first resistor circuit 110 includes resistors R11, R12, R13, R14, R15, and R16, which are connected in series. More specifically, for example, one end of resistor R11 is connected to the output node of the first bias current BC1, and the other end is connected to one end of resistor R12. The other end of resistor R12 is connected to one end of resistor R13, the other end of resistor R13 is connected to one end of resistor R14, the other end of resistor R14 is connected to one end of resistor R15, the other end of resistor R15 is connected to one end of resistor R16, and the other end of resistor R16 is connected to a ground node. Here, resistors R11, R13, and R15 are first unit resistors, for example, diffused resistors with positive temperature characteristics. Furthermore, resistors R12, R14, and R16 are second unit resistors, for example, polysilicon resistors with negative temperature characteristics. That is, Figure 4 and Figure 3 The difference lies in the fact that resistors with positive temperature coefficients (TCCs) and resistors with negative TCCs are alternately connected in series. However, in Figure 4 In the first resistor circuit 110, the combined resistor value is the sum of the individual resistance values ​​of resistors R11 to R16. This is to ensure that the temperature characteristic of the combined resistor in the first resistor circuit 110 is flat, which is consistent with... Figure 3 Same. Furthermore, in Figure 4 In this example, the value of the combined resistance of the first resistor circuit 110 can also be changed by switch control. Specifically, the first resistor circuit 110 may also include... Figure 4 The switch shown in A2. Therefore, when the switch shown in A2 is open, the combined resistance of the first resistor circuit 110 becomes the sum of the resistances of resistors R11 to R16. When the switch shown in A2 is closed, the combined resistance of the first resistor circuit 110 becomes the sum of the resistances of resistors R15 and R16, thus changing the combined resistance of the first resistor circuit 110. Furthermore, in Figure 4 In the example, even if the resistance value of the combined resistor of the first resistor circuit 110 is changed, the temperature characteristic of the first resistor remains flat. Thus, in the temperature detection circuit 100 of this embodiment, the diffusion resistor of the first resistor circuit 110 comprises n first unit resistors (n is an integer greater than or equal to 2), and the polysilicon resistor of the first resistor circuit 110 comprises n second unit resistors. The n first unit resistors and the n second unit resistors are connected in series, and the resistance ratio of the first unit resistors to the second unit resistors is the same as the resistance ratio of the polysilicon resistor to the diffusion resistor. Therefore, the first resistor circuit 110, which flattens the first temperature characteristic, can be constructed using the first unit resistors and the second unit resistors.

[0050] Figure 5 This is a diagram illustrating an example of the structure of the second resistor circuit 120. In Figure 5 In the circuit, the second resistor circuit 120 includes resistors R21, R22, R23, R24, R25, R26, R27, and R28, which are connected in series. More specifically, for example, one end of resistor R21 is connected to the output node of the second bias current BC2, and the other end is connected to one end of resistor R22. Additionally, the other end of resistor R22 is connected to one end of resistor R23, the other end of resistor R23 is connected to one end of resistor R24, the other end of resistor R24 ​​is connected to one end of resistor R25, the other end of resistor R25 is connected to one end of resistor R26, the other end of resistor R26 is connected to one end of resistor R27, the other end of resistor R27 is connected to one end of resistor R28, and the other end of resistor R28 is connected to the ground node.

[0051] in addition, Figure 5 Resistors R21 through R28 shown are all polycrystalline silicon resistors with negative temperature resistance characteristics, as described later. Figure 6 , Figure 7 The explanation is based on this premise. However, as mentioned above, since it is sufficient for the first resistance temperature characteristic and the second resistance temperature characteristic to be different from each other, resistors R21 to R28 can all be diffusion resistors with positive resistance temperature characteristics.

[0052] Alternatively, the second resistor circuit 120 can also be a variable resistor circuit. Specifically, the second resistor circuit 120 can operate as a variable resistor circuit by also including the switches shown in A11 to A18. When all switches shown in A11 to A18 are open, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21 to R28. When only switch shown in A11 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R22 to R28. When only switch shown in A12 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21 and R23 to R28. When only switch shown in A13 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21, R22, and R24 to R28. When only the switch shown in A14 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21-R23 and R25-R28. When only the switch shown in A15 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21-R24 and R26-R28. When only the switch shown in A16 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21-R25, R27, and R28. When only the switch shown in A17 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21-R26 and R28. When only the switch shown in A18 is on, the combined resistance of the second resistor circuit 120 is the sum of the resistance values ​​of resistors R21-R27.

[0053] Furthermore, although detailed explanations are omitted, it is permissible for two or more switches shown in A11-A18 to be turned on, provided that the combination of switches that are turned on is appropriately determined. For example, the temperature detection circuit 100 includes... Figure 5 The fine-tuning circuit is not shown in the figure. The fine-tuning circuit includes, for example, a non-volatile memory, and outputs a signal to control the on / off state of the switches shown in A11-A18 in a manner corresponding to the desired trim value, referring to a trim value stored in the non-volatile memory. Thus, the resistance value of the second resistor circuit 120 can be variably controlled according to the trim value. In other words, in a resistance-temperature characteristic curve with resistance value on the vertical axis and temperature on the horizontal axis, the intercept value of the second resistance-temperature characteristic can be variably controlled by the trim value. Since the second voltage-temperature characteristic is determined based on the second resistance-temperature characteristic, the second voltage-temperature characteristic can be variably controlled by the trim value. Therefore, the temperature at which the first voltage-temperature characteristic and the second voltage-temperature characteristic intersect can be adjusted by the trim value.

[0054] Thus, in the temperature detection circuit 100 of this embodiment, the second resistor circuit 120 is a variable resistor circuit whose resistance value is set by a trim value, such that the first voltage-temperature characteristic and the second voltage-temperature characteristic intersect at the target temperature TD. This makes it easy to adjust the target temperature TD while taking into account manufacturing deviations. Specifically, for example, due to manufacturing deviations in the wafer involved in the temperature detection circuit 100, the data of the first resistance temperature characteristic, the second resistance temperature characteristic, and the target temperature TD at their intersection may not be consistent with the design data, and adjustments need to be made after manufacturing. In this case, adjusting the target temperature TD by fixing the first temperature characteristic and changing the second temperature characteristic is more convenient than adjusting the target temperature TD by fixing the second temperature characteristic and changing the first temperature characteristic. This is because, as described above, the first resistor circuit 110 is composed of a polysilicon resistor and a diffusion resistor, while the second resistor circuit 120 is composed of only a polysilicon resistor or only a diffusion resistor.

[0055] Figure 6 The upper section of the diagram illustrates an example of the relationship between the temperature characteristics of the first and second resistors. When the temperature detection circuit 100 operates in its normal mode, the temperature characteristics of the first resistor are shown in A20, and the temperature characteristics of the second resistor are shown in A30. The temperature at the intersection of the temperature characteristics of the first resistor shown in A20 and the temperature characteristics of the second resistor shown in A30 is called the detected temperature TD. For example, when the temperature characteristics of the first bias current BC1 and the second bias current BC2 output by the bias current generation circuit 102 are flat, in... Figure 6 The lower section of the diagram illustrates the relationship between the first voltage temperature characteristic and the second voltage temperature characteristic. When the temperature detection circuit 100 operates in its normal mode, the first voltage temperature characteristic is shown in B20, and the second voltage temperature characteristic is shown in B30. The temperature at the intersection of the first voltage temperature characteristic shown in B20 and the second voltage temperature characteristic shown in B30 is the target temperature TD. That is, when the temperature around the temperature detection circuit 100 is lower than the target temperature TD, the second voltage V2 is higher than the first voltage V1; when the temperature around the temperature detection circuit 100 is higher than the target temperature TD, the second voltage V2 is lower than the first voltage V1. Therefore, when the second voltage V2 becomes lower than the first voltage V1, the detection signal output from the comparator circuit 130 changes.

[0056] Furthermore, when the temperature detection circuit 100 is operated in test mode, the combined resistance of the first resistor circuit 110 increases, therefore, the temperature characteristic of the first resistor is as shown in A21. The temperature at the intersection of the first resistor temperature characteristic shown in A21 and the second resistor temperature characteristic shown in A30 is the test temperature TE. The test temperature TE is a temperature lower than the target temperature TD. Additionally, when the temperature detection circuit 100 is operated in test mode, the temperature characteristic of the first voltage is as shown in B21. The temperature at the intersection of the first voltage temperature characteristic shown in B21 and the second voltage temperature characteristic shown in B30 is the test temperature TE. Since the first resistor temperature characteristic is a negative temperature characteristic and the second resistor temperature characteristic is flat, by increasing the combined resistance of the first resistor circuit 110 in test mode, the test temperature TE can be made lower than the target temperature TD.

[0057] in addition, Figure 6 This is an example of a case where the temperature characteristic of the current output by the bias current generation circuit 102 is flat, but the current output by the bias current generation circuit 102 can also have temperature characteristics. For example, it is preferable to flatten the second voltage temperature characteristic based on the temperature characteristic of the current output by the bias current generation circuit 102 and the temperature characteristic of the second resistor. This is because it is easy to set the intersection point of the first voltage temperature characteristic and the second voltage temperature characteristic.

[0058] Figure 7 This is an example of a case where the method of this embodiment is applied when the first bias current BC1 and the second bias current BC2 output by the bias current generation circuit 102 have positive temperature characteristics. Figure 7 The upper part of the image and Figure 6 The above diagram is the same, therefore the explanation is omitted. Figure 7 In the lower figure, when the temperature detection circuit 100 operates in normal mode, the first voltage temperature characteristic is shown as C20, and the second voltage temperature characteristic is shown as C30. The temperature at the intersection of the first voltage temperature characteristic shown in C20 and the second voltage temperature characteristic shown in C30 is the temperature TD to be detected. Furthermore, when the temperature detection circuit 100 operates in test mode, the first voltage temperature characteristic is shown as C21, and the temperature at the intersection of the first voltage temperature characteristic shown in C21 and the second voltage temperature characteristic shown in C30 is the test temperature TE. Thus, even if the current output by the bias current generation circuit 102 has a temperature characteristic, the method of this embodiment can still be applied.

[0059] For example, during factory testing of the circuit device 10, the temperature detection circuit 100 is set to test mode. With the ambient temperature of the circuit device 10 set to the test temperature TE, the output signal of the comparison circuit 130 is monitored while the adjustment value of the second resistor circuit 120 is changed. Furthermore, the test device writes the adjustment value when the output signal of the comparison circuit 130 is reversed into the aforementioned fine-tuning circuit. This results in an adjustment value where the resistance value of the second resistor circuit 120 matches the resistance value of the first resistor circuit 110. Therefore, the temperature TD of the object to be detected can be set to the desired temperature.

[0060] Based on the above, in the temperature detection circuit 100 of this embodiment, the first resistor circuit 110 is a variable resistor circuit with different resistance values ​​set in normal mode and test mode. The resistance value of the first resistor circuit 110 is the resistance value corresponding to a test temperature TE that is lower than the target temperature TD in test mode. Furthermore, in test mode, the first voltage-temperature characteristic and the second voltage-temperature characteristic are set to cross at the test temperature TE. Therefore, in normal mode, a correction value is set so that the first voltage-temperature characteristic and the second voltage-temperature characteristic cross at the target temperature TD. Thus, the circuit device 10 including the temperature detection circuit 100 can be tested at a test temperature TE that is lower than the target temperature TD. This simplifies the testing process.

[0061] Additionally, the circuit device 10 of this embodiment may also include a bandgap reference circuit 101. Furthermore, in this case, for example... Figure 8 As shown, the bias current generation circuit 102 can generate a first bias current BC1 and a second bias current BC2 by mirroring the bias current inside the bandgap reference circuit 101. Figure 8 An example of the structure of the bandgap reference circuit 101 and the bias current generation circuit 102 in this case is shown.

[0062] exist Figure 8 In the circuit, the bandgap reference circuit 101 includes transistors TR1, TR2, TR3, TR4, TR5, and TR6, resistors R51, R52, and R53, and an operational amplifier OP. Although detailed illustrations are omitted, the operational amplifier OP can be configured, for example, by a differential circuit having differential pair transistors and an output circuit that outputs an output voltage based on a signal from the differential circuit.

[0063] Transistor TR1 is a P-type MOS transistor, located between node NA, which serves as the high-potential power supply node, and the node at the inverting input terminal of the operational amplifier OP. More specifically, node NA is, for example, the output node of a power supply circuit (not shown). More specifically, in... Figure 8 In this configuration, the source of transistor TR1 is connected to node N1, which has the same potential as node NA. Furthermore, the drain of transistor TR1 is connected to node N4, which is the inverting input terminal of operational amplifier OP. Additionally, the gate of transistor TR1 is connected to node N5, which has the same potential as node N15. Node N15 is connected to the other end of resistor R53, one end of which is connected to the output terminal of operational amplifier OP.

[0064] Transistors TR2 and TR3 are both P-type MOS transistors, forming a current mirror circuit together with transistor TR1. The source of transistor TR2 is connected to node N2, which is at the same potential as node NA. The gate of transistor TR2 is connected to node N5, and the drain of transistor TR2 is connected to node N6, which is the node of the non-inverting input terminal of operational amplifier OP. Furthermore, the source of transistor TR3 is connected to node N3, which is at the same potential as node NA. The drain of transistor TR3 is connected to node N8, and the gate of transistor TR3 is connected to node N7.

[0065] Transistor TR4 is a PNP bipolar transistor. By short-circuiting the base and collector, the PN junction between the emitter and base functions as a diode. More specifically, the emitter of transistor TR4 becomes the anode and is connected to node N4, which is at the same potential as the node at the inverting input terminal of operational amplifier OP. The collector of transistor TR4 is connected to node N10, which is at the same potential as node NB, the low-potential power supply node. The base of transistor TR4 is connected to node N9, which is at the same potential as node NB. Furthermore, node NB is more specifically, for example, a ground node, but any node with a constant potential is acceptable.

[0066] Transistor TR5 is a PNP bipolar transistor. By short-circuiting the base and collector, the PN junction between the emitter and base functions as a diode. More specifically, the emitter of transistor TR5 is connected to the other end of resistor R52, and one end of resistor R52 is connected to node N6. Node N6 is at the same potential as the node at the non-inverting input terminal of operational amplifier OP. The collector of transistor TR5 is connected to node N14, which is at the same potential as node NB. The base of transistor TR5 is connected to node N13, which is at the same potential as node NB.

[0067] Resistor R51 is positioned between the node of the inverting input terminal of operational amplifier OP and the low-potential power supply node. More specifically, one end of resistor R51 is connected to node N11, which is at the same potential as the node of the inverting input terminal of operational amplifier OP, and the other end of resistor R51 is connected to node N12, which is at the same potential as node NB.

[0068] Transistor TR6 is an N-type MOS transistor, which, together with transistor TR15 (described later), forms a current mirror circuit. The drain of transistor TR6 is connected to node N8, the source of transistor TR6 is connected to node N16, and the gate of transistor TR6 is connected to node N17. Node N16 is at the same potential as node NB, which serves as the low-potential power supply node.

[0069] so, Figure 8 The bandgap reference circuit 101 places transistors TR1 and TR2 between node NA and the inverting and non-inverting input terminals of operational amplifier OP. The gates of these transistors TR1 and TR2 are controlled by the output of operational amplifier OP. Thus, feedback control is achieved by virtually grounding the operational amplifier OP, making the inverting and non-inverting input terminals have the same voltage. Consequently, feedback-controlled current flows through transistor TR4, which is connected in series with transistor TR1, and transistor TR5, which is connected in series with transistor TR2, enabling the output of a reference voltage based on the bandgap voltage.

[0070] The current D1 flowing through transistor TR2 can be expressed using a first defined formula based on the base-emitter voltage of transistor TR4, the base-emitter voltage difference, the resistance values ​​of resistors R51, R52, and R53. Details of this first defined formula are omitted as they are known. Furthermore, the base-emitter voltage difference refers to the difference between the base-emitter voltage of transistor TR4 and the base-emitter voltage of transistor TR5. This base-emitter voltage difference can be expressed using a second defined formula based on the ratio of the emitter areas of transistors TR4 and TR5, the Boltzmann constant, the absolute temperature, and the electron charge. Details of this second defined formula are also omitted as they are known.

[0071] The bias current generation circuit 102 includes transistors TR11, TR12, TR13, TR14, and TR15.

[0072] Transistor TR11 is a P-type MOS transistor. The source of transistor TR11 is connected to node NC, and the gate of transistor TR11 is connected to node N7. Node NC is at the same potential as the high-potential power supply node. As described above, transistor TR11, together with transistors TR1~TR3, forms a current mirror circuit. Therefore, the current flowing through transistor TR11 is the current obtained by mirroring the currents flowing through transistors TR1~TR3.

[0073] Transistors TR12, TR13, and TR14 are all P-type MOS transistors, forming a current mirror circuit. The source of transistor TR12 is connected to node ND, the drain to node NF, and the gate to node NE. Node ND is at the same potential as the high-potential power supply node. The source of transistor TR13 is connected to node NG, which is at the same potential as the high-potential power supply node. The gate of transistor TR13 is connected to node NH, which is at the same potential as node NE. The source of transistor TR14 is connected to node NJ, which is at the same potential as the high-potential power supply node. The gate of transistor TR14 is connected to node NH, which is at the same potential as node NE.

[0074] Transistor TR15 is an N-type MOS transistor, which, together with transistor TR6 mentioned above, forms a current mirror circuit. The drain of transistor TR15 is connected to node NF, the source of transistor TR15 is connected to node NK, and the gate of transistor TR15 is connected to node N17, which is a node at the same potential as the low-potential side power supply node.

[0075] Transistors TR2 and TR3 form a current mirror circuit, transistor TR6 is connected in series with transistor TR3, transistor TR6 and TR15 form a current mirror circuit, and transistor TR12 is connected in series with transistor TR15. Therefore, the current flowing through transistor TR12 is a mirror image of the current flowing through transistor TR2. Furthermore, transistors TR13 and TR14, together with transistor TR12, form a current mirror circuit. Therefore, the current flowing through the drain of transistor TR13, as shown in D3, is a mirror image of the current shown in D1. Similarly, the current flowing through the drain of transistor TR14, as shown in D4, is a mirror image of the current shown in D1. When the gate size of transistor TR13 and transistor TR14 are the same, the magnitude of the current flowing through the drain of transistor TR13, as shown in D3, is the same as the magnitude of the current flowing through the drain of transistor TR14, as shown in D4.

[0076] Furthermore, by connecting the drain of transistor TR13 to the output node of the first bias current BC1, and connecting the drain of transistor TR14 to the output node of the second bias current BC2, the first bias current BC1 and the second bias current BC2 can be generated as the same current. That is, Figure 8 The current shown in D3 corresponds to the first bias current BC1. Figure 8 The current shown in D4 corresponds to the second bias current BC2, which is a relationship obtained by mirroring the bias current inside the bandgap reference circuit 101. Furthermore, the drain of transistor TR11 can be connected to the bias input node of comparator circuit 130.

[0077] Furthermore, although the illustrations are omitted, the transistor pairs constituting these current mirror circuits can be configured in a way that aligns their centroids in the layout, using a so-called common centroid layout. This allows for a further reduction in the magnitude difference of the mirrored currents.

[0078] Thus, the circuit device 10 of this embodiment includes the temperature detection circuit 100 and the bandgap reference circuit 101 described above. The bias current generation circuit 102 generates a first bias current BC1 and a second bias current BC2 by mirroring the bias current inside the bandgap reference circuit 101. Therefore, it is possible to construct a bias current generation circuit 102 that generates the first bias current BC1 and the second bias current BC2 based on the bandgap reference circuit 101.

[0079] The circuit device 10 of this embodiment can also be more specifically described as... Figure 9 The structure is as shown in the example. Figure 9 The circuit device 10, in addition to including Figure 2 In addition to the structure shown, it also includes a power receiving circuit 11, a charging circuit 12, and a charging system control circuit 13. Furthermore, Figure 9 The circuit device 10 can also be used together with the power supply device 20 to form a contactless power transmission system. In this case, the circuit device 10 operates as a power receiving device that receives power from the power supply device 20 in a contactless manner.

[0080] The power transmission device 20 is a device for transmitting power to the circuit device 10 in a contactless manner, and includes a power transmission circuit 21 and a primary coil shown in L1. The power transmission circuit 21 includes a power transmission driver that drives the primary coil, a power supply circuit that supplies power to the power transmission driver, and a capacitor that forms a resonant circuit with the primary coil. The power transmission circuit 21 configured in this way generates an alternating voltage of a predetermined frequency during power transmission and supplies this alternating voltage to the primary coil. The primary coil and the secondary coil (described later) are electromagnetically coupled to form a transformer for power transmission. For example, when power transmission is needed, the magnetic flux of the primary coil passes through the secondary coil. On the other hand, when power transmission is not needed, the magnetic flux of the primary coil does not pass through the secondary coil. In addition, although not shown in the figure, the power transmission device 20 also includes a power transmission side control circuit for performing various controls on the power transmission side. Specifically, the power transmission side control circuit includes, for example, a communication circuit, a power supply voltage control circuit, a clock generation circuit, and a driver control circuit. The communication circuit receives power transmission voltage setting information from the power receiving side. The power supply voltage control circuit generates a drive voltage to drive the power supply driver based on the power supply voltage setting information. The clock generation circuit generates a drive clock signal that specifies the power supply frequency. The driver control circuit controls the power supply driver based on the drive voltage and the drive clock signal.

[0081] The charging system control circuit 13 controls the charging circuit 12 and performs various control processes during the charging process of the battery 30. The charging system control circuit 13 can be implemented, for example, using logic circuits generated by an automatic configuration wiring method such as a gate array, or various processors such as a DSP (Digital Signal Processor). The receiving circuit 11 converts the AC induced voltage of the secondary coil shown in L2 into a DC rectified voltage. That is, the receiving circuit 11 includes a rectifier circuit (not shown). The rectifier circuit can be implemented, for example, using multiple transistors, diodes, etc. The charging circuit 12 supplies power to the battery 30 based on the power involved in the rectified voltage converted by the receiving circuit 11. The structure of the circuit device 10 is not limited to... Figure 9 For example, it may also include a communication circuit that sends communication data to the power supply device 20. In addition, the charging system control circuit 13 can further control the aforementioned communication circuit and power receiving circuit 11, enabling various modifications.

[0082] In the circuit device 10 configured in this way, for example, when the ambient temperature of the temperature detection circuit 100 reaches the temperature TD of the target object, the detection signal output from the comparison circuit 130 changes. As a result, the shutdown circuit 15 shuts down the charging system control circuit 13. For example, the shutdown circuit 15 outputs a signal indicating that the charging system control circuit 13 is set to shutdown mode, during which the charging system control circuit 13 does not perform charging control of the battery 30.

[0083] Based on the above, the circuit device 10 of this embodiment includes: a receiving circuit 11 that receives power based on contactless power transmission; a charging circuit 12 that charges the battery 30 based on the received power; and a charging system control circuit 13 that controls the charging circuit 12 and a shutdown circuit 15 that shuts off the charging system control circuit 13. Thus, a circuit device 10 can be constructed that shuts off the charging system control circuit 13 when the ambient temperature reaches the temperature TD of the target object.

[0084] Alternatively, for example, regarding the temperature detection circuit 100 of this embodiment, the layout design of the diffusion resistor and the polysilicon resistor can also be as follows. Figure 10 In the conceptual chip layout shown in E1, the part shown in E10 is the layout of the diffusion resistors, and the part shown in E20 is the layout of the polysilicon resistors.

[0085] In the layout shown in E10, multiple rectangular diffusion resistors are arranged in a grid pattern. Here, the length of the long side of the rectangle along the current flow direction is called the "length," and the length of the short side of the rectangle perpendicular to the current flow direction is called the "width." That is, in the layout shown in E10, multiple diffusion resistors are arranged with the width shown in E11 and the length shown in E12. Similarly, in the layout shown in E20, multiple rectangular polysilicon resistors are arranged with the width shown in E21 and the length shown in E22.

[0086] Here, the width shown in E11 is the same as the width shown in E21. "Same" includes what is essentially considered the same error range. That is, in the temperature detection circuit 100 of this embodiment, the polysilicon resistor and the diffusion resistor have the same width in the first resistor circuit 110. Therefore, the resistance ratio of the polysilicon resistor to the diffusion resistor is determined solely by the relationship between the length of the polysilicon resistor and the length of the diffusion resistor. Thus, the resistance ratio of the polysilicon resistor to the diffusion resistor can be easily set.

[0087] As described above, the temperature detection circuit of this embodiment includes: a bias current generation circuit that generates a first bias current and a second bias current; a first resistor circuit that supplies the first bias current; a second resistor circuit that supplies the second bias current; and a comparison circuit. The comparison circuit compares the first voltage and the second voltage and outputs the comparison result as a temperature detection signal. The first voltage is generated by the first bias current flowing through the first resistor circuit, and the second voltage is generated by the second bias current flowing through the second resistor circuit. Furthermore, the second voltage temperature characteristic of the second voltage is different from the first voltage temperature characteristic of the first voltage.

[0088] Thus, the temperature detection circuit of this embodiment uses a first resistor circuit and a second resistor circuit to make the temperature characteristics of the first voltage and the temperature characteristics of the second voltage different. Therefore, it is possible to achieve different comparison results at the desired temperature with a simpler circuit structure.

[0089] In addition, the first voltage-temperature characteristic and the second voltage-temperature characteristic can also overlap at the temperature of the object being detected.

[0090] Therefore, the detection signal output from the comparison circuit can be made different at the temperature of the object being detected, thus enabling the construction of a temperature detection circuit for detecting the temperature of the object being detected.

[0091] Alternatively, the second resistor circuit can also be a variable resistor circuit whose resistance value is set by a trim value. The trim value can be set in such a way that the first voltage-temperature characteristic and the second voltage-temperature characteristic cross at the temperature of the object being detected.

[0092] Therefore, it is easy to adjust the temperature of the object being tested while taking into account manufacturing deviations.

[0093] Alternatively, the first resistor circuit may be a variable resistor circuit with different resistance values ​​set in normal mode and test mode, wherein the resistance value of the first resistor circuit is the resistance value corresponding to a test temperature lower than the temperature of the object being tested in test mode. Alternatively, in test mode, the first voltage-temperature characteristic and the second voltage-temperature characteristic may be set to cross at the test temperature, thereby setting a trimming value in normal mode in a manner that causes the first voltage-temperature characteristic and the second voltage-temperature characteristic to cross at the temperature of the object being tested.

[0094] Therefore, circuit devices containing temperature detection circuits can be tested in an environment with a test temperature lower than that of the object being tested. This simplifies the testing process.

[0095] In addition, the resistance value of the first resistor circuit can have a first resistance temperature characteristic, and the resistance value of the second resistor circuit can have a second resistance temperature characteristic that is different from that of the first resistor.

[0096] Therefore, the temperature characteristics of the first voltage can be different from those of the second voltage.

[0097] In addition, the first resistance temperature characteristic can be a flat temperature characteristic, and the second resistance temperature characteristic can be a positive or negative temperature characteristic.

[0098] Therefore, it is easy to set the intersection point of the first resistance temperature characteristic and the second resistance temperature characteristic.

[0099] Alternatively, the first resistor circuit can be composed of resistors with positive temperature characteristics and resistors with negative temperature characteristics, and the second resistor circuit can be composed of resistors with either positive or negative temperature characteristics.

[0100] Therefore, the temperature characteristics of the first resistor can be different from those of the second resistor.

[0101] Furthermore, the first resistor circuit can be composed of a polysilicon resistor and a diffusion resistor, and the second resistor circuit can be composed of a polysilicon resistor or a diffusion resistor.

[0102] Therefore, it is possible to construct a temperature detection circuit that includes a first resistor circuit and a second resistor circuit using polysilicon resistors and diffusion resistors.

[0103] In addition, in the first resistor circuit, the widths of the polysilicon resistor and the diffusion resistor can be the same.

[0104] Therefore, the resistance ratio of the polysilicon resistor to the diffusion resistor can be easily set.

[0105] Alternatively, in the first resistor circuit, the resistance ratio of the polysilicon resistor to the diffusion resistor can be the resistance ratio that makes the temperature characteristic of the first resistor flat.

[0106] Therefore, a first resistor circuit with flat temperature characteristics can be constructed using a polycrystalline silicon resistor with negative temperature characteristics and a diffusion resistor with positive temperature characteristics.

[0107] Alternatively, the diffusion resistor of the first resistor circuit may contain n first unit resistors (n being an integer greater than 2), and the polysilicon resistor of the first resistor circuit may contain n second unit resistors. The n first unit resistors and the n second unit resistors are connected in series, and the resistance ratio of the first unit resistor to the second unit resistor is the same as the resistance ratio of the polysilicon resistor to the diffusion resistor.

[0108] Therefore, a first resistive circuit with a flat first temperature characteristic can be constructed using the first unit resistor and the second unit resistor.

[0109] Alternatively, the first resistor circuit may include a switch for test mode, which is connected in parallel with k first unit resistors (k being an integer greater than or equal to 1 and less than n) and k second unit resistors.

[0110] Therefore, the resistance value of the first resistor circuit can be changed, and thus, in test mode, the temperature characteristics of the first resistor and the temperature characteristics of the second resistor can intersect at a lower temperature.

[0111] Furthermore, this embodiment relates to a circuit device that includes the temperature detection circuit and the bandgap reference circuit described above. The bias current generation circuit generates a first bias current and a second bias current by mirroring the bias current inside the bandgap reference circuit.

[0112] Therefore, it is possible to construct a bias voltage generation circuit based on a bandgap reference circuit to generate a first bias current and a second bias current.

[0113] Furthermore, this embodiment relates to a circuit device that includes: the temperature detection circuit described above; and a shutdown circuit that shuts off the circuit device when a detection signal indicating that the temperature is the temperature of the object being detected is output.

[0114] Therefore, it is possible to construct a circuit device that performs a shutdown operation based on the detection signal output from the temperature detection circuit to achieve the effects of this embodiment.

[0115] Furthermore, the aforementioned circuit device may also include: a receiving circuit that receives power based on contactless power transmission; a charging circuit that charges the battery based on the received power; and a charging system control circuit that controls the charging circuit, wherein the shutdown circuit can execute the shutdown of the charging system control circuit.

[0116] Therefore, a circuit device can be constructed that shuts off the charging system control circuit 13 when the ambient temperature reaches the temperature of the object being detected.

[0117] Furthermore, while this embodiment has been described in detail above, those skilled in the art will readily understand that various modifications can be made without substantially departing from the new aspects and effects of this disclosure. Therefore, all such modifications are included within the scope of this disclosure. For example, a term described at least once in the specification or drawings along with a different, broader, or synonymous term can be replaced with that different term anywhere in the specification or drawings. Moreover, all combinations of this embodiment and its modifications are also included within the scope of this disclosure. Furthermore, the structure and operation of temperature detection circuits and circuit devices are not limited to those described in this embodiment, and various modifications can be implemented.

Claims

1. A temperature detection circuit, characterized in that, The temperature detection circuit includes: A bias current generating circuit generates a first bias current and a second bias current. The first resistor circuit, through which the first bias current flows; The second resistor circuit, through which the second bias current flows; as well as A comparator circuit compares a first voltage and a second voltage and outputs the comparison result as a temperature detection signal. The first voltage is generated by a first bias current flowing through the first resistor circuit, and the second voltage is generated by a second bias current flowing through the second resistor circuit. The second voltage temperature characteristic of the second voltage is different from the first voltage temperature characteristic of the first voltage.

2. The temperature detection circuit according to claim 1, characterized in that, The first voltage-temperature characteristic and the second voltage-temperature characteristic intersect at the temperature of the object being detected.

3. The temperature detection circuit according to claim 2, characterized in that, The second resistor circuit is a variable resistor circuit whose resistance value is set by a trimming value. The adjustment value is set in such a way that the first voltage-temperature characteristic and the second voltage-temperature characteristic intersect at the temperature of the object being detected.

4. The temperature detection circuit according to claim 3, characterized in that, The first resistor circuit is a variable resistor circuit with different resistance values ​​set in normal mode and test mode. In the test mode, the resistance value of the first resistor circuit is a resistance value corresponding to a test temperature that is lower than the temperature of the object being tested. The trim value is set by setting the first voltage-temperature characteristic and the second voltage-temperature characteristic to intersect at the test temperature in the test mode, and by setting the first voltage-temperature characteristic and the second voltage-temperature characteristic to intersect at the test object temperature in the normal mode.

5. The temperature detection circuit according to claim 1, characterized in that, The resistance value of the first resistor circuit has a first resistance temperature characteristic. The resistance value of the second resistor circuit has a second resistance temperature characteristic that is different from that of the first resistor.

6. The temperature detection circuit according to claim 5, characterized in that, The first resistance temperature characteristic is a flat temperature characteristic. The second resistance temperature characteristic is either positive or negative.

7. The temperature detection circuit according to claim 5, characterized in that, The first resistor circuit consists of resistors with positive temperature characteristics and resistors with negative temperature characteristics. The second resistor circuit is composed of resistors with positive or negative temperature characteristics.

8. The temperature detection circuit according to claim 7, characterized in that, The first resistor circuit consists of a polysilicon resistor and a diffusion resistor. The second resistor circuit is composed of the polysilicon resistor or the diffusion resistor.

9. The temperature detection circuit according to claim 8, characterized in that, In the first resistor circuit, the polysilicon resistor has the same width as the diffusion resistor.

10. The temperature detection circuit according to claim 8, wherein, In the first resistor circuit, the resistance ratio of the polysilicon resistor to the diffusion resistor is the resistance ratio that makes the temperature characteristic of the first resistor flat.

11. The temperature detection circuit according to claim 10, characterized in that, The diffusion resistor in the first resistor circuit comprises n first unit resistors, where n is an integer greater than or equal to 2. The polysilicon resistor in the first resistor circuit comprises n second unit resistors. n first unit resistors and n second unit resistors are connected in series. The resistance ratio of the first unit resistor to the second unit resistor is the same as the resistance ratio of the polycrystalline silicon resistor to the diffusion resistor.

12. The temperature detection circuit according to claim 11, characterized in that, The first resistor circuit includes a switch for test mode. The switch is connected in parallel with k first unit resistors and k second unit resistors, where k is an integer greater than or equal to 1 and less than n.

13. A circuit device, characterized in that, The circuit device includes: The temperature detection circuit according to any one of claims 1 to 12; and Bandgap reference circuit, The bias current generation circuit generates the first bias current and the second bias current by mirroring the bias current inside the bandgap reference circuit.

14. A circuit device, characterized in that, The circuit device includes: The temperature detection circuit according to any one of claims 1 to 12; and The circuit shuts off when the detection signal, representing the temperature of the object being detected, is output.

15. The circuit device according to claim 14, characterized in that, The circuit device includes: A receiving circuit that accepts power based on contactless power transmission; A charging circuit that charges the battery based on the received power; and The charging system control circuit controls the charging circuit. The shutdown circuit shuts down the charging system control circuit.

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