Thermometer chip capable of rapidly detecting fault

Abstract

The utility model discloses a thermometer chip capable of rapidly detecting faults, which relates to the field of electronic thermometers, and comprises an oscillator circuit, a frequency output control circuit and a counting display circuit, the oscillator circuit is connected with the counting display circuit through the frequency output control circuit, the oscillator circuit comprises a thermometer peripheral circuit, and the frequency output control circuit is connected with the counting display circuit through the frequency output control circuit. The frequency output control circuit is used for generating a control signal V4 according to an output signal of the oscillator, and the control signal V4 is used for controlling the counting display circuit to display a fault mark when a peripheral circuit of the thermometer breaks down. The thermometer chip can improve the fault test efficiency during the mass production stage test of thermometers.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic clinical thermometer field, especially a clinical thermometer chip of quick detection failure. BACKGROUND

[0002] Because traditional mercury clinical thermometer has the disadvantage such as measurement time -consuming, cannot automatic reading, material has harmfulness, in recent years, digital electronic clinical thermometer has gradually become the mainstream of today's medical clinical thermometer. Digital electronic clinical thermometer detects temperature through the relationship between thermistor and reference resistance value, converts resistance value into frequency using RC oscillation principle, uses ROM and combines circuit design finally to map frequency signal into actual temperature, realizes the measurement of temperature. From 2026, our country will completely prohibit the production of clinical thermometer containing mercury, then digital electronic clinical thermometer demand will continue to improve, this to digital electronic clinical thermometer's quick whole machine manufacturing and yield guarantee has put forward higher requirement.

[0003] Digital electronic clinical thermometer chip peripheral circuit has thermistor, reference resistance, capacitor element etc. that cooperate to produce frequency, in the welding assembly process, the abnormal problem such as device damage, short circuit cannot be avoided. Therefore, how to test in the mass production stage, quickly troubleshoot whether clinical thermometer assembly finished product exists peripheral device damage, short circuit etc. abnormality is the problem that urgently needs to be solved. UTILITY MODEL CONTENTS

[0004] The applicant proposes a clinical thermometer chip capable of quickly detecting faults in view of the above problems and technical needs.

[0005] The technical solution of the utility model is as follows:

[0006] A clinical thermometer chip capable of quickly detecting faults, comprising an oscillator circuit, a frequency output control circuit and a counting display circuit, the oscillator circuit is connected with the counting display circuit through the frequency output control circuit, wherein,

[0007] The oscillator circuit comprises a clinical thermometer peripheral circuit, the frequency output control circuit is used to generate a control signal V4 according to the output signal of the oscillator, and the control signal V4 is used to control the counting display circuit to display a fault mark when the clinical thermometer peripheral circuit fails.

[0008] A further technical solution is that the clinical thermometer peripheral circuit comprises a thermistor SENSOR_RES, a reference resistance REF_RES and a capacitor C1; the oscillator circuit comprises a switch tube M1 and a switch tube M2;

[0009] One end of the thermistor SENSOR_RES and one end of the reference resistor REF_RES are grounded through the capacitor C1, the other end of the reference resistor REF_RES is connected with the third electrode of the switch tube M1, the second electrode of the switch tube M1 is connected with the enable signal EN_REF, and the first electrode of the switch tube M1 is connected with the power supply voltage VDD.

[0010] The other end of the thermistor SENSOR_RES is connected with the third electrode of the switch tube M2, the second electrode of the switch tube M2 is connected with the enable signal EN_SENSOR, and the first electrode of the switch tube M2 is connected with the power supply voltage VDD.

[0011] Further, the output signal of the oscillator includes a first output signal V1 and a second output signal V2.

[0012] Further, the oscillator circuit further includes an inverting Schmitt trigger SMT1, a switch tube M3 and a NAND gate NAND1, wherein,

[0013] The input end of the inverting Schmitt trigger SMT1 is connected with the third electrode of the switch tube M3 and one end of the capacitor C1, and forms a first output end of the oscillator circuit, for outputting the first output signal V1.

[0014] Further, the second input end of the NAND gate NAND1 is connected with the enable signal EN, the first input end of the NAND gate NAND1 is connected with the output end of the inverting Schmitt trigger SMT1, and forms a second output end of the oscillator circuit, for outputting the second output signal V2.

[0015] The output end of the NAND gate NAND1 is connected with the second electrode of the switch tube M3, and the first electrode of the switch tube M3 is connected with the other end of the capacitor C1 and grounded.

[0016] Further, the switch tube M1 and the switch tube M2 are PMOS tubes, and the switch tube M3 is an NMOS tube.

[0017] Further, the frequency output control circuit includes a NAND gate NAND2, an inverter INV1 and a capacitor C2, wherein,

[0018] The input end of the inverter INV1 is connected with the first output end of the oscillator circuit, the output end of the inverter INV1 and one end of the capacitor C2 and the first input end of the NAND gate NAND2 are connected;

[0019] The other end of the capacitor C2 is connected to a power supply voltage VDD, the second input end of the NAND gate NAND2 is connected to the second output end of the oscillator circuit, and the output end of the NAND gate NAND2 is connected to the input end of the counting display circuit.

[0020] Further, the control signal V4 is used to control the counting display circuit to display the temperature measured by the thermometer when the thermometer peripheral circuit is fault-free.

[0021] Further, the counting display circuit comprises a temperature counting unit and a display control circuit, wherein the display control circuit is used to control an LCD, and the LCD is used to display a fault mark or the temperature measured by the thermometer.

[0022] The thermometer chip provided by the present application has the following beneficial technical effects:

[0023] The thermometer chip provided by the present application can make the LCD display a fault mark through the counting display circuit when the thermometer peripheral circuit is faulty. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a circuit schematic diagram of an embodiment of the thermometer chip provided by the present application. DETAILED DESCRIPTION

[0025] The specific embodiments described herein are intended to be illustrative only and are not limiting of the present disclosure.

[0026] The present application provides a thermometer chip capable of quickly detecting faults. Figure 1 As shown in the figure, the thermometer chip comprises an oscillator circuit, a frequency output control circuit and a counting display circuit.

[0027] The oscillator circuit comprises a thermometer peripheral circuit, the frequency output control circuit is used to generate a control signal V4 according to the output signal of the oscillator, and the control signal V4 is used to control the counting display circuit to display a fault mark when the thermometer peripheral circuit is faulty.

[0028] Specifically, the thermometer is a digital electronic thermometer, and the detected fault specifically refers to whether there is an abnormal problem such as component damage and short circuit after the peripheral circuit of the thermometer is assembled by welding. In an embodiment of the utility model, the control signal V4 is kept in a high level state when the peripheral circuit of the thermometer fails, the control signal V4 is loaded to the counting display circuit to control the counting display circuit to display a fault mark, and the form of the fault mark can be an "ERR" character. Therefore, when the thermometer chip provided by the utility model is tested in the mass production stage of the thermometer, whether there is an abnormal problem such as component damage and short circuit in the assembled product (the thermometer) can be intuitively and quickly investigated according to the fault mark, and the efficiency of fault testing is improved.

[0029] The control signal V4 can also be used to control the counting display circuit to count and perform digital logic processing to display the measured temperature when the peripheral circuit of the thermometer does not fail. The counting display circuit can include a thermometer counting unit and a display control circuit, wherein the display control circuit is used to control an LCD (Liquid Crystal Display), and the measured temperature or the fault mark can be displayed on the LCD. The specific form and working principle of the oscillator circuit, the frequency output control circuit and the counting display circuit can be referred to the following description. The specific form of the thermometer counting unit and the display control circuit can be consistent with the prior art.

[0030] Further, the elements in the peripheral circuit of the thermometer include a thermistor SENSOR_RES, a reference resistor REF_RES and a capacitor C1; the oscillator circuit includes a switch tube M1, a switch tube M2, a switch tube M3, an inverting Schmitt trigger SMT1 and a NAND gate NAND1;

[0031] One end of the thermistor SENSOR_RES and one end of the reference resistor REF_RES are grounded through the capacitor C1, the other end of the reference resistor REF_RES is connected with the third electrode of the switch tube M1, the second electrode of the switch tube M1 is connected with an enable signal EN_REF, and the first electrode of the switch tube M1 is connected with a power supply voltage VDD;

[0032] The other end of the thermistor SENSOR_RES is connected with the third electrode of the switch tube M2, the second electrode of the switch tube M2 is connected with an enable signal EN_SENSOR, and the first electrode of the switch tube M2 is connected with the power supply voltage VDD.

[0033] The output signal of the oscillator includes a first output signal V1 and a second output signal V2. The input end of the inverting Schmitt trigger SMT1 is connected with the third electrode of the switch tube M3 and one end of the capacitor C1, and forms a first output end of the oscillator circuit, for outputting the first output signal V1. The second input end of the NAND gate NAND1 is connected with the enable signal EN, the first input end of the NAND gate NAND1 is connected with the output end of the inverting Schmitt trigger SMT1, and forms a second output end of the oscillator circuit, for outputting the second output signal V2; the output end of the NAND gate NAND1 is connected with the second electrode of the switch tube M3, and the first electrode of the switch tube M3 is connected with the other end of the capacitor C1 and grounded.

[0034] Specifically, in the embodiment, the switch tube M1 and the switch tube M2 are PMOS tubes, and the switch tube M3 is an NMOS tube. For the PMOS tube and the NMOS tube, the first electrode is the source, the second electrode is the gate, and the third electrode is the drain.

[0035] The specific working principle of the oscillator circuit is as follows: when the oscillator circuit starts to work, the enable signals EN_REF and EN_SENSOR correspondingly control the switch tube M1 and the switch tube M2 to be turned on alternately, so as to correspondingly control the reference resistor REF_RES and the thermistor SENSOR_RES to be connected to the power supply voltage VDD through the switch tube M1 and the switch tube M2 alternately, so as to charge the capacitor C1 through the reference resistor REF_RES / thermistor SENSOR_RES. At this time, the first output signal V1 is a high-level signal, and the second output signal V2 is a low-level signal.

[0036] The low-level second output signal V2 is input to the first input terminal of the NAND gate NAND1, and the enable signal EN controls the oscillator circuit to be enabled, the high-level enable signal EN is input to the second input terminal of the NAND gate NAND1, the NAND gate NAND1 outputs a high-level voltage signal V0, the voltage signal V0 turns on the switch tube M3, the first output signal V1 voltage value is rapidly reduced at the drain of the switch tube M3, and when the first output signal V1 voltage is lower than the low-voltage flip threshold voltage of the inverting Schmitt trigger SMT1, the second output signal V2 voltage changes from low to high, that is, the second output signal V2 becomes a high-level signal. At this time, the second output signal V2 and the enable signal EN are both high-level signals, and the voltage signal V0 is flipped to a low-level signal, so that the switch tube M3 is turned off. At the same time, the power supply voltage VDD is connected to the reference resistor REF_RES / thermistor SENSOR_RES through the turned-on switch tube M1 / switch tube M2, and the capacitor C1 is charged. With the accumulation of charges, the first output signal V1 voltage value gradually rises, and when the first output signal V1 voltage is higher than the high-voltage flip threshold voltage of the inverting Schmitt trigger SMT1, the second output signal V2 voltage changes from high to low, that is, the second output signal V2 becomes a low-level signal again, and the voltage signal V0 changes to a high-level signal again. Thus, a oscillation cycle is completed, and the cycle is repeated.

[0037] Further, the frequency output control circuit comprises a NAND gate NAND2, an inverter INV1 and a capacitor C2, wherein,

[0038] The input terminal of the inverter INV1 is connected with the first output terminal of the oscillator circuit, the output terminal of the inverter INV1 and one end of the capacitor C2 and the first input terminal of the NAND gate NAND2 are connected;

[0039] The other end of the capacitor C2 is connected with the power supply voltage VDD, the second input terminal of the NAND gate NAND2 is connected with the second output terminal of the oscillator circuit, and the output terminal of the NAND gate NAND2 is connected with the input terminal of the counting display circuit.

[0040] Specifically, the output terminal of the NAND gate NAND2 is used to form the output terminal of the frequency output control circuit, and is used to output the control signal V4. The specific working principle of the control signal V4 generated by the frequency output control circuit in operation is as follows: the first output signal V1 is input to the inverter INV1, and is output from the inverter INV1 to one end of the capacitor C2. The voltage signal V3 is generated by charging and discharging the capacitor C2, the voltage signal V3 is input to the first input terminal of the NAND gate NAND2, the second output signal V2 is input to the second input terminal of the NAND gate NAND2, and the voltage signal V3 and the second output signal V2 are output from the NAND gate NAND2 as the control signal V4 after being input to the NAND gate NAND2.

[0041] When the peripheral circuit of the thermometer is in good condition, the control signal V4 is an oscillation signal, the counting and display circuit counts according to the oscillation frequency of the control signal V4, and displays the measured temperature after logical processing. When the peripheral circuit of the thermometer is in fault, that is, any one / more of the reference resistor REF_RES, the thermistor SENSOR_RES and the capacitor C1 is short-circuited or abnormally welded or damaged, the frequency of the output signal of the oscillator circuit is abnormally increased compared with when the peripheral circuit of the thermometer is in good condition, and the first output signal V1 rapidly oscillates between the low voltage flip threshold voltage and the high voltage flip threshold voltage of the inverting Schmitt trigger SMT1.

[0042] As can be known from the above description, in the frequency output control circuit, the control signal V4 is generated based on the voltage signal V3, the voltage signal V3 is generated by charging and discharging of the capacitor C2, and the charging and discharging rate of the capacitor C2 is affected by the capacitance value of the capacitor C2 and the delay time of the inverter INV1. Therefore, in order to reflect the fault condition of the peripheral circuit of the thermometer through the control signal V4, the utility model reduces the charging and discharging rate of the capacitor C2 by setting the capacitance value of the capacitor C2 and the size of the inverter INV1, so that the capacitor C2 cannot be charged in time when the oscillation frequency of the first output signal V1 is too high, so that the voltage of the voltage signal V3 cannot be raised, the voltage signal V3 is always a low level signal, and therefore the control signal V4 remains a high level signal, that is, the control signal V4 has no frequency output, and at this time the counting and display circuit displays the fault mark. In specific implementation, the capacitance value of the capacitor C2 and the size of the inverter INV1 can be selected according to actual application conditions, so as to make the control signal V4 remain a high level signal when the peripheral circuit of the thermometer is in fault.

[0043] In the description of the present specification, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. The features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0044] Those skilled in the art should understand that the above is only a preferred embodiment of the utility model, and the utility model is not limited to the above embodiments. It can be understood that other improvements and changes directly derived or thought of by those skilled in the art without departing from the spirit and concept of the utility model should be considered to be included in the protection scope of the utility model.

Claims

1. A thermometer chip capable of rapidly detecting faults, characterized in that, The oscillator circuit, the frequency output control circuit and the counting display circuit are connected, wherein The oscillator circuit comprises a thermometer peripheral circuit, the frequency output control circuit is used to generate a control signal V4 according to the output signal of the oscillator, and the control signal V4 is used to control the counting display circuit to display a fault mark when the thermometer peripheral circuit fails.

2. The thermometric chip capable of fast detection of failure according to claim 1, wherein, The thermometer peripheral circuit comprises a thermistor SENSOR_RES, a reference resistor REF_RES and a capacitor C1; and the oscillator circuit comprises a switch tube M1 and a switch tube M2. One end of the thermistor SENSOR_RES and one end of the reference resistor REF_RES are grounded through the capacitor C1, the other end of the reference resistor REF_RES is connected with the third electrode of the switch tube M1, the second electrode of the switch tube M1 is connected with an enable signal EN_REF, and the first electrode of the switch tube M1 is connected with a power supply voltage VDD. The other end of the thermistor SENSOR_RES is connected with the third electrode of the switch tube M2, the second electrode of the switch tube M2 is connected with an enable signal EN_SENSOR, and the first electrode of the switch tube M2 is connected with the power supply voltage VDD.

3. The thermometric chip capable of rapidly detecting a failure according to claim 2, characterized by, The output signal of the oscillator comprises a first output signal V1 and a second output signal V2.

4. The thermometric chip capable of rapidly detecting a failure according to claim 3, characterized by, The oscillator circuit further comprises an inverting Schmitt trigger SMT1, a switch tube M3 and a NAND gate NAND1, wherein The input end of the inverting Schmitt trigger SMT1 is connected with the third electrode of the switch tube M3 and one end of the capacitor C1, and forms a first output end of the oscillator circuit, and is used to output the first output signal V1.

5. The thermometric chip capable of fast detection of failure according to claim 4, wherein, The second input end of the NAND gate NAND1 is connected with an enable signal EN, the first input end of the NAND gate NAND1 is connected with the output end of the inverting Schmitt trigger SMT1, and forms a second output end of the oscillator circuit, and is used to output the second output signal V2; The output end of the NAND gate NAND1 is connected with the second electrode of the switch tube M3, and the first electrode of the switch tube M3 is connected with the other end of the capacitor C1 and grounded.

6. The thermometric chip capable of fast detection of failure according to claim 4, wherein, The switch tube M1 and the switch tube M2 are PMOS tubes, and the switch tube M3 is an NMOS tube.

7. The thermometric chip capable of fast detection of failure according to claim 5, wherein, The frequency output control circuit comprises a NAND gate NAND2, an inverter INV1 and a capacitor C2, wherein The input end of the inverter INV1 is connected with the first output end of the oscillator circuit, the output end of the inverter INV1 and one end of the capacitor C2 and the first input end of the NAND gate NAND2 are connected; The other end of the capacitor C2 is connected with the power supply voltage VDD, the second input end of the NAND gate NAND2 is connected with the second output end of the oscillator circuit, and the output end of the NAND gate NAND2 is connected with the input end of the counting display circuit.

8. The fast fault detectable thermometer chip according to claim 1, wherein The control signal V4 is also used to control the counting display circuit to display the temperature measured by the thermometer when the thermometer peripheral circuit is fault-free.

9. The thermometric chip capable of fast detection of failure according to claim 8, wherein, The counting display circuit comprises a thermometer counting unit and a display control circuit, wherein The display control circuit is used to control the LCD, which is used to display the fault mark or the temperature measured by the thermometer.

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