A fully CMOS temperature and voltage sensor based on leakage current

Abstract

The application discloses a full CMOS temperature and voltage sensor based on leakage current. The sensor comprises two parts of an analog part and a digital part; the analog part is placed in a measured environment and comprises a temperature sensing oscillator, a reference oscillator and a voltage sensing oscillator; the digital part comprises three counters, two D flip-flops and a processor; the three counters count clock frequencies output by the oscillators of the analog part to obtain count values and send the count values to the two D flip-flops and the processor; the two D flip-flops receive two count values and then control output count values to the processor; and the processor receives the count values to correct the count values and obtain temperature and voltage. The application senses a power supply voltage through leakage current of CMOS for the first time, measures two environmental variables of temperature and voltage by using only three oscillators, corrects by using a reference oscillator, reduces mutual influences, has small area, is highly compatible and is applicable to most CMOS processes above 22 nm.

Description

Technical Field

[0001] This invention relates to a digital processing circuit for temperature and voltage sensing, and more particularly to a full CMOS temperature and voltage sensing method based on leakage current. Background Technology

[0002] Due to the thermal management requirements of today's high-performance microprocessors and System-on-Chip (SoC), research on on-chip temperature sensors compatible with CMOS processes remains crucial. As integrated circuit process nodes shrink and circuit integration density increases, the resulting chip self-heating phenomenon becomes increasingly severe. Therefore, processor or SoC designs require numerous on-chip temperature sensors to perform real-time temperature monitoring at different locations and provide feedback to adjust frequency and voltage, thereby achieving dynamic chip performance regulation and overheat protection. This also places higher demands on the area and power consumption of temperature sensors.

[0003] Integrated intelligent CMOS temperature sensors refer to fully integrated systems that combine silicon-based temperature sensing devices, sensor bias circuits, analog-to-digital converters, and even subsequent digital signal processing and digital calibration modules into a single unit. In standard CMOS processes, many devices exhibit temperature-dependent physical characteristics, and theoretically, all of these devices can serve as temperature sensing components in CMOS temperature sensors. Currently, commonly used temperature sensing devices in CMOS temperature sensors include BJTs, MOSFETs, and resistors. Furthermore, temperature measurement can also be achieved by utilizing the thermal diffusivity of silicon substrates. Bipolar transistor (BJT)-based sensors are widely used due to their high accuracy over a wide temperature range of -55 to 125°C. However, they are incompatible with advanced processes requiring power supplies below 1V. Resistor-based sensors offer high energy efficiency and resolution, but passive components like resistors and capacitors require a large area. Thermally diffusive sensors can operate at power supply voltages below 1V and occupy a small area, but they often consume milliwatts of power, and the heat generated introduces additional inaccuracies.

[0004] In recent years, time-domain based all-MOS temperature sensors have gradually emerged, employing temperature-dependent delay circuits. Among them, digital temperature sensors based on ring oscillators (RO) can operate at supply voltages below 1V and have a latency below 0.01mm. 2 With its small area and microwatt-level power consumption, this ring oscillator is a novel temperature sensor worthy of further research and is well-suited for applications requiring low-power solutions, such as IoT. However, the ring oscillator is quite sensitive to changes in power supply voltage. Summary of the Invention

[0005] To address the problems existing in the background technology, this invention proposes a full CMOS temperature and voltage sensor based on leakage current. This invention utilizes the low power consumption advantage of the CMOS leakage current principle and the small area advantage of full MOSFETs to realize a temperature sensor insensitive to power supply voltage and a voltage sensor insensitive to temperature, achieving simultaneous and accurate detection of both voltage and temperature.

[0006] The technical solution adopted in this invention is:

[0007] This invention comprises two parts: an analog part and a digital part.

[0008] The simulation component is placed in the environment under test, including:

[0009] Temperature-sensing oscillator (TRO) is sensitive to temperature.

[0010] The reference oscillator RO-ref is not sensitive to temperature or voltage.

[0011] A voltage-sensing oscillator (VRO) is sensitive to voltage.

[0012] The digital portion is not placed in the environment under test, including:

[0013] Three counters, Accumulator, are connected to the outputs of the temperature-sensing oscillator (TRO), the reference oscillator (RO-ref), and the voltage-sensing oscillator (VRO), respectively. They count the clock frequencies output by each oscillator in the analog section to obtain count values, which are then sent to two D flip-flops and the processor.

[0014] Two D flip-flops receive count values ​​from two of the three Accumulator outputs, and then process and control the output of one count value from each of them to the processor;

[0015] The processor receives two sets of count values ​​from two D flip-flops, and simultaneously receives the count value from the reference oscillator RO-ref after passing through the counter Accumulator, performs relevant corrections, and obtains the temperature and voltage.

[0016] The two D flip-flops mentioned are a temperature D flip-flop and a voltage D flip-flop, respectively;

[0017] The temperature sensing oscillator (TRO) outputs a temperature count value through its own counter (Accumulator), and inputs the temperature count value to the data input terminal of the temperature D flip-flop.

[0018] The voltage sensing oscillator VRO outputs a voltage count value through its own Accumulator, and then inputs the voltage count value to the data input terminal of the voltage D flip-flop;

[0019] The reference oscillator RO-ref outputs a reference count value through its own counter Accumulator, and the reference count value is input to the clock input of the temperature D flip-flop and the voltage D flip-flop, as well as the processor, respectively;

[0020] Both the temperature D flip-flop and the voltage D flip-flop receive a reference count value at their clock inputs. Once the reference count value reaches the same preset count threshold, they output their respective temperature / voltage count values ​​to the processor.

[0021] The reference oscillator RO-ref outputs a reference count value through its respective counter Accumulator. The reference count value is then input to the temperature D flip-flop, voltage D flip-flop, and processor after passing through the state machine.

[0022] The temperature-sensing oscillator (TRO) and voltage-sensing oscillator (VRO) output temperature and voltage count values ​​via their respective counters (Accumulators). These count values ​​are then input to the temperature and voltage D flip-flops via binary-to-Gray code converters.

[0023] The temperature-sensing oscillator (TRO), reference oscillator (RO-ref), and voltage-sensing oscillator (VRO) all include a sensing unit, a differential ring oscillator (Core), a differential operational amplifier (Comparator), and a buffer. The two output terminals of the differential ring oscillator (Core) are respectively connected to the non-inverting input terminal and the inverting input terminal of the differential operational amplifier (Comparator). The output terminal of the differential operational amplifier (Comparator) is connected to the input terminal of the counter (Accumulator) via the buffer. The voltage input terminal of the differential ring oscillator (Core) is connected to the power supply voltage, and the ground terminal of the differential ring oscillator (Core) is connected to ground. At least one sensing unit is connected in series between the voltage input terminal and the ground terminal of the differential ring oscillator (Core).

[0024] In the aforementioned differential ring oscillator (Core), the four differential delay units (DelayCells) are connected end-to-end to form a loop, with the output of one DelayCell connected to the input of the next. Specifically, between the third and fourth differential delay units, the positive and negative differential output ports of the previous DelayCell are cross-connected with the negative and positive differential output ports of the next DelayCell. Each pair of differential delay units (DelayCells) is connected by corresponding positive and negative differential output ports of the previous and subsequent differential delay units (DelayCells). The positive and negative differential output ports of the fourth differential delay unit (DelayCell) are used as the two output terminals of the differential ring oscillator (Core), which are then connected to the non-inverting and inverting input terminals of the differential operational amplifier (Comparator), respectively. The voltage input terminals and ground terminals of the four differential delay units (DelayCells) are connected to the power supply voltage and ground, respectively.

[0025] The sensing units are all mainly composed of a MOS transistor. The source and gate of the MOS transistor are shorted, the drain of the MOS transistor is connected to the differential ring oscillator Core, and the source of the MOS transistor is connected to the power supply voltage or ground.

[0026] In the processor, the voltage count value is corrected based on the division result between the temperature count value and the reference count value to obtain an accurate voltage;

[0027] At the same time, the temperature count value is corrected based on the division result between the voltage count value and the reference count value to obtain an accurate temperature.

[0028] The voltage count value is corrected based on the division between the temperature count value and the reference count value to obtain an accurate voltage. Specifically, the correction process is performed according to the following formula:

[0029]

[0030] Where, N VRO F represents the voltage-sensing oscillator count value. VRO N represents the frequency value of the voltage-sensing oscillator. set F represents the set reference oscillator count value. set This indicates the set frequency value of the reference oscillator, and U represents the final voltage data.

[0031] The temperature count value is corrected based on the division between the voltage count value and the reference count value to obtain an accurate temperature. Specifically, the correction process is performed according to the following formula:

[0032]

[0033] Where, N TRO F represents the temperature-sensing oscillator count value. TRO N represents the frequency value of the temperature-sensing oscillator. set F represents the set reference oscillator count value. set This represents the set frequency value of the reference oscillator, and T represents the final temperature data.

[0034] The temperature insensitivity / voltage sensitivity described in this invention is achieved by comparing and eliminating the similarity detection results of the reference oscillator RO-ref and the temperature-sensing oscillator TRO, or the similarity detection results of the reference oscillator RO-ref and the voltage-sensing oscillator VRO. In other words, it doesn't mean that the reference oscillator RO-ref is completely insensitive to temperature; it simply means that the two oscillators have different sensitivities to temperature / voltage under different conditions. Figure 3 The first picture provides an explanation.

[0035] The sensor of this invention can accurately detect temperature and voltage simultaneously in the desired environment, solving the problems of temperature changes affecting accurate voltage detection and voltage changes affecting accurate temperature detection in the same environment.

[0036] The beneficial effects of this invention are:

[0037] This invention is the first to sense power supply voltage through CMOS leakage current, and uses only three oscillators to measure two environmental variables, temperature and voltage, and uses a reference oscillator for correction, reducing mutual interference.

[0038] Because this invention is entirely composed of CMOS, it has strong compatibility with various processes and is applicable to most CMOS processes above 22nm.

[0039] Because this invention uses leakage current drive, the power consumption of the analog part is only in the nanowatt range, and the total power consumption of the digital part does not exceed 10 microwatts, while mainstream sensors require more than 10 microwatts. Since it is entirely composed of CMOS, the area is also quite small, making it suitable for deployment in fields such as the Internet of Things where power consumption and area are critical. Attached Figure Description

[0040] Figure 1 It is a custom architecture diagram of temperature and voltage sensors based on leakage current;

[0041] Figure 2 This is a basic structural diagram of each oscillator in the sensor;

[0042] Figure 3 These are temperature and voltage sensitivity characteristics of three types of ring oscillators;

[0043] Figure 4 These are schematic diagrams of the specific temperature sensing structures of three types of ring oscillators;

[0044] Figure 5 It is a waveform diagram of the output of each stage of the analog circuit. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0046] like Figure 1 As shown, it includes two parts: an analog section and a digital section;

[0047] The simulation component is placed in the environment under test, including:

[0048] Temperature-sensing oscillator (TRO) is sensitive to temperature.

[0049] The reference oscillator RO-ref is not sensitive to temperature or voltage.

[0050] A voltage-sensing oscillator (VRO) is sensitive to voltage.

[0051] The digital portion is not placed in the environment under test, including:

[0052] Three counters, Accumulator, are connected to the outputs of the temperature-sensing oscillator (TRO), the reference oscillator (RO-ref), and the voltage-sensing oscillator (VRO), respectively. They count the clock frequencies output by each oscillator in the analog section to obtain count values, which are then sent to two D flip-flops and the processor.

[0053] Two D flip-flops receive count values ​​from two of the three Accumulator outputs, and then process and control the output of one count value from each of them to the processor;

[0054] The processor receives two sets of count values ​​from two D flip-flops, and simultaneously receives the count value from the reference oscillator RO-ref after passing through the counter Accumulator. It performs relevant corrections to eliminate interference errors in temperature and voltage, thereby obtaining temperature and voltage.

[0055] The two D flip-flops are a temperature D flip-flop and a voltage D flip-flop, respectively;

[0056] The temperature sensing oscillator (TRO) outputs a temperature count value through its own counter (Accumulator), and inputs the temperature count value to the data input terminal of the temperature D flip-flop.

[0057] The voltage sensing oscillator VRO outputs a voltage count value through its own Accumulator, and then inputs the voltage count value to the data input terminal of the voltage D flip-flop;

[0058] The reference oscillator RO-ref outputs a reference count value through its own counter Accumulator, and the reference count value is input to the clock input of the temperature D flip-flop and the voltage D flip-flop, as well as the processor, respectively;

[0059] Both the temperature D flip-flop and the voltage D flip-flop receive a reference count value at their clock inputs. Once the reference count value reaches the same preset count threshold, they output their respective temperature / voltage count values ​​to the processor.

[0060] The reference oscillator RO-ref outputs a reference count value through its own counter Accumulator. The reference count value is then input to the temperature D flip-flop, voltage D flip-flop, and processor after passing through the state machine.

[0061] Temperature-sensing oscillator (TRO) and voltage-sensing oscillator (VRO) output temperature and voltage count values ​​via their respective Accumulators. These count values ​​are then converted from binary to Gray code and input to the temperature and voltage D flip-flops, respectively.

[0062] In the digital section, a counter counts the input electrical frequency, converting the analog information in the frequency into a digital signal; a binary-to-Gray code converter converts multi-bit transitions into single-bit transitions to avoid large errors; and a state machine controls the counter's counting, reading, and clearing states in the digital circuit.

[0063] Temperature-sensing oscillator (TRO), reference oscillator (RO-ref), and voltage-sensing oscillator (VRO), such as Figure 2 As shown, each includes a sensing unit, a differential ring oscillator (Core), a differential operational amplifier (Comparator), and a buffer. The two output terminals of the differential ring oscillator (Core) are respectively connected to the non-inverting input terminal and the inverting input terminal of the differential operational amplifier (Comparator). The output terminal of the differential operational amplifier (Comparator) is connected to the input terminal of the counter (Accumulator) via the buffer. The voltage input terminal of the differential ring oscillator (Core) is connected to the power supply voltage, and the ground terminal of the differential ring oscillator (Core) is connected to ground. At least one sensing unit is connected in series between the voltage input terminal and the ground terminal of the differential ring oscillator (Core).

[0064] In specific implementation, one or more sensing units can be connected in series between the voltage input terminal of the differential ring oscillator core and the power supply voltage, or one or more sensing units can be connected in series between the voltage input terminal of the differential ring oscillator core and the ground terminal, or one or more sensing units can be connected in series simultaneously between the voltage input terminal of the differential ring oscillator core and the power supply voltage, and between the voltage input terminal of the differential ring oscillator core and the ground terminal.

[0065] The differential ring oscillator (Core) generates a wave of a specific frequency. The sensing unit detects temperature / voltage information through leakage current, which then charges and discharges the parasitic capacitance inside the differential delay unit (DelayCell). The differential operational amplifier amplifies the two-stage differential signal, and the waveform is shaped into a standard square wave through a buffer. Figure 5 As shown.

[0066] The specific implementation also includes registers. By writing the output structure into the register through a buffer, metastability can be avoided.

[0067] In the differential ring oscillator (Core), the four differential delay cells (DelayCells) are connected end-to-end to form a loop, with the output of one DelayCell connected to the input of the next. Specifically, between the third and fourth differential delay cells, the positive and negative differential output ports of the previous DelayCell are cross-connected to the negative and positive differential output ports of the next DelayCell. The remaining cells are connected in a similar manner. The two differential delay units (DelayCells) are directly connected by their corresponding positive and negative differential output ports. The positive and negative differential output ports of the fourth differential delay unit (DelayCell) are used as the two output terminals of the differential ring oscillator (Core), which are then connected to the non-inverting and inverting input terminals of the differential operational amplifier (Comparator), respectively. The voltage input terminals and ground terminals of the four differential delay units (DelayCells) are connected to the power supply voltage and ground, respectively. In this way, the four differential delay units constitute a pseudo-differential ring oscillator.

[0068] Each sensing unit is mainly composed of a MOSFET. The source and gate of the MOSFET are shorted together. The drain of the MOSFET is connected to the voltage input terminal and ground terminal of the differential delay unit DelayCell in the differential ring oscillator Core. The source of the MOSFET is connected to the power supply voltage or ground.

[0069] In the processor, the voltage count is corrected based on the division between the temperature count and the reference count to obtain an accurate voltage; at the same time, the temperature count is corrected based on the division between the voltage count and the reference count to obtain an accurate temperature.

[0070] In specific implementation, the sensing units of the temperature sensing oscillator (TRO), the reference oscillator (RO-ref), and the voltage sensing oscillator (VRO) are configured differently. Specifically, the types of MOS transistors in the sensing units are different or the number of transistors stacked is different. The MOS transistors in the sensing units of the voltage sensing oscillator (VRO) and the reference oscillator (RO-ref) are low threshold voltage MOS transistors (LVTs), while the MOS transistors in the sensing units of the temperature sensing oscillator (TRO) are conventional threshold voltage MOS transistors (RVTs).

[0071] In specific implementation, such as Figure 4 As shown, the temperature-sensing oscillator (TRO) has two low-threshold voltage MOSFETs (RVTs) connected in series between the voltage input terminal of the differential ring oscillator (Core) and the power supply voltage. The reference oscillator (RO-ref) has two conventional threshold voltage MOSFETs (RVTs) connected in series between the voltage input terminal of the differential ring oscillator (Core) and the power supply voltage. The voltage-sensing oscillator (VRO) has only one low-threshold voltage MOSFET (LVT) connected in series between the voltage input terminal of the differential ring oscillator (Core) and the power supply voltage.

[0072] The temperature-sensing oscillator (TRO), reference oscillator (RO-ref), and voltage-sensing oscillator (VRO) all employ a differential ring oscillator (Core) structure. This invention generates an oscillation frequency by charging and discharging the parasitic capacitance of the three identical differential ring oscillator Cores using the leakage current controlled by the sensing unit. This invention utilizes the leakage current of the MOSFET in the sensing unit under subthreshold conditions; the logarithmic value of the leakage current has an exponential relationship with temperature and a linear relationship with the power supply voltage. The oscillation frequency generated by the three ring oscillators changes with temperature or voltage variations. The differential ring oscillator Cores are connected to the sensing unit to form a ring oscillator (RO) with a sensing unit.

[0073] The outputs of three ring oscillators (ROs) with sensing units are amplified by operational amplifiers and then passed through two stages of buffers to obtain a relatively ideal square wave signal. Two of the ROs have different temperature sensitivities but similar voltage sensitivities, allowing them to sense temperature regardless of voltage. The other two ROs have different voltage sensitivities but similar temperature sensitivities, allowing them to sense voltage regardless of temperature. The shared RO used for correction is designated as the reference ring oscillator, denoted as RO-ref. The RO used for temperature sensing is designated as the temperature-sensing oscillator, denoted as TRO, and the RO used for voltage sensing is designated as the voltage-sensing oscillator, denoted as VRO. This design adds one more RO than a typical dual-RO temperature sensor, but still achieves voltage sensing. The square waves generated by the three ROs are counted by a counter, converting the analog frequency signal into a digital signal for subsequent signal processing. When the count result of the reference ring oscillator RO-ref reaches a certain value N... set At that time, the counting results of the other two ROs are output. The temperature and voltage information can be measured by the pairwise ratio. The other two ROs need to be converted to Gray code after counting. The final output result needs to be registered twice to avoid metastability.

[0074] The main flow of the analog section is as follows. The most important component is the MOSFET used to sense temperature and voltage. It mainly operates in the subthreshold region, and the leakage current it generates follows an exponential relationship with the temperature, as shown in the following equation:

[0075]

[0076]

[0077] Where μ is the channel carrier mobility, C ox It is a gate oxide capacitor, W and L are the width and length of the MOSFET, respectively, and V T This is the thermal voltage of the MOSFET, k is the Boltzmann constant, and V GS It is the gate-source voltage of the MOSFET, V TH It is the threshold voltage of the MOSFET, V SB It is the source voltage of the MOSFET, V DS λ is the drain-source voltage of the MOSFET, and λ is the channel modulation coefficient of the MOSFET. I0 represents the thermal current of the MOSFET; T represents the temperature, e represents the electron charge constant, and I leak represents the leakage current of the MOSFET, exp represents the exponential function, and n represents the process constant.

[0078] Taking the logarithm of both sides of the formula, extracting the temperature-related terms, and omitting some irrelevant terms, the formula simplifies to:

[0079]

[0080] Where F is the output frequency of the oscillator, A is a temperature-independent term that can be adjusted by changing the aspect ratio, and B is mainly affected by the threshold voltage and the power supply voltage. Furthermore, simulations show that V... DS With V DD Previously, a linear relationship existed, which can be obtained from (1):

[0081] ln F=α·V DD +β (3)

[0082] Where α and β are the first and second fitting parameters, respectively, with α adjusted by stacking the number of transistors, and V DD The voltage represents the power supply voltage. As can be seen from (2) and (3), the logarithm of the oscillator output frequency has a basically linear relationship with the reciprocal of the temperature and the voltage. This is the core principle of the temperature and voltage sensor based on leakage current in this invention.

[0083] In formula (2), B is mainly affected by the threshold voltage and the power supply voltage. B is the factor affecting the temperature sensitivity of RO. The difference between the temperature sensing oscillator TRO and the reference oscillator RO-ref is that they use different threshold voltage MOSFETs, resulting in different temperature sensitivities. However, the number of MOSFETs stacked is the same, so their voltage sensitivities are similar.

[0084] In formula (3), α can be adjusted by adjusting the number of MOSFETs stacked in the sensing unit. The difference between the reference oscillator RO-ref and the voltage sensing oscillator VRO lies in the number of stacked MOSFETs, resulting in different voltage sensitivities. However, the MOSFETs used are both LVT, so their temperature sensitivities are similar.

[0085] In practice, the current from the power supply voltage, through the leakage current generated by the sensing unit, charges the parasitic capacitance of each delay unit in the ring oscillator, forming a wave of a certain frequency. This signal is amplified by a differential operational amplifier, then passed through two buffer stages, and finally shaped into a regular square wave signal for digital circuit processing. Figure 5 As shown.

[0086] In the specific implementation, a total of temperature sensing oscillators (TRO), reference oscillators (RO-ref), and voltage sensing oscillators (VRO) were used. The main difference lies in the different sensing units. Different voltage and temperature sensitivities can be achieved by adjusting the number of sensing units stacked together and the threshold voltage.

[0087] By finding two sets of oscillators with similar voltage sensitivities but different temperature sensitivities, temperature information independent of voltage fluctuations can be obtained; similarly, by finding two sets of oscillators with similar temperature sensitivities but different voltage sensitivities, voltage information independent of temperature can be obtained. Figure 3As shown, this enables dual monitoring of temperature and voltage. The final three-channel oscillator structure obtained through simulation testing using Huahong's 40nm process is shown below. Figure 4 As shown.

[0088] The main process of the digital section is as follows: The digital module counts the levels of three square wave signals generated by the temperature-sensing oscillator (TRO), the reference oscillator (RO-ref), and the voltage-sensing oscillator (VRO) in the analog section. The three signal sources respectively clock three counters, with the signal source generated by RO-ref serving as the overall system clock. When the level counter of RO-ref reaches a specified value, the counting results N of TRO and VRO are output. TRO and N VRO Since this process involves multiple bit transitions, the count results of TRO and VRO need to be converted to Gray code, and then the Gray code results are stored. The state machine includes four states: reset, count, read, and clear. In the reset state, all registers are set to zero. In the count state, the three signal sources are counted. In the read state, when the count value of signal source RO-ref reaches the specified value N... set When the sensor is in the zero state, it outputs the count results in Gray code form for TRO and VRO. When the sensor is in the zero state, it has completed one measurement and clears all registers on the digital side.

[0089] The present invention also requires secondary correction of the circuit to make the output results more accurate. It also requires two-point correction to adapt to various process angles and reduce errors under different processes.

Claims

1. A full CMOS temperature and voltage sensor based on leakage current, characterized in that: It consists of two parts: an analog section and a digital section. The simulation component is placed in the environment under test, including: Temperature-sensing oscillator (TRO) is sensitive to temperature. The reference oscillator RO-ref is not sensitive to temperature or voltage. A voltage-sensing oscillator (VRO) is sensitive to voltage. The digital portion includes: Three counters, Accumulator, are connected to the outputs of the temperature-sensing oscillator (TRO), the reference oscillator (RO-ref), and the voltage-sensing oscillator (VRO), respectively. They count the clock frequencies output by each oscillator in the analog section to obtain count values, which are then sent to two D flip-flops and the processor. Two D flip-flops receive count values ​​from two of the three Accumulator outputs, and then process and control the output of one count value from each of them to the processor; The processor receives two sets of count values ​​from two D flip-flops, and simultaneously receives the count value from the reference oscillator RO-ref after passing through the counter Accumulator, performs relevant corrections, and obtains the temperature and voltage. The temperature-sensing oscillator (TRO) and voltage-sensing oscillator (VRO) output temperature and voltage count values ​​via their respective counters (Accumulators). These count values ​​are then input to the temperature and voltage D flip-flops via binary-to-Gray code converters.

2. The all-CMOS temperature and voltage sensor based on leakage current according to claim 1, characterized in that: The two D flip-flops mentioned are a temperature D flip-flop and a voltage D flip-flop, respectively; The temperature sensing oscillator (TRO) outputs a temperature count value through its own counter (Accumulator), and inputs the temperature count value to the data input terminal of the temperature D flip-flop. The voltage sensing oscillator VRO outputs a voltage count value through its own Accumulator, and then inputs the voltage count value to the data input terminal of the voltage D flip-flop; The reference oscillator RO-ref outputs a reference count value through its own counter Accumulator, and the reference count value is input to the clock input of the temperature D flip-flop and the voltage D flip-flop, as well as the processor, respectively; Both the temperature D flip-flop and the voltage D flip-flop receive a reference count value at their clock inputs. Once the reference count value reaches the same preset count threshold, they output their respective temperature / voltage count values ​​to the processor.

3. The all-CMOS temperature and voltage sensor based on leakage current according to claim 1, characterized in that: The reference oscillator RO-ref outputs a reference count value through its respective counter Accumulator. The reference count value is then input to the temperature D flip-flop, voltage D flip-flop, and processor after passing through the state machine.

4. A full CMOS temperature and voltage sensor based on leakage current according to claim 1, characterized in that: The temperature sensing oscillator (TRO), reference oscillator (RO-ref), and voltage sensing oscillator (VRO) all include a sensing unit, a differential ring oscillator (Core), a differential operational amplifier (Comparator), and a buffer. The two outputs of the differential ring oscillator Core are connected to the non-inverting input and the inverting input of the differential operational amplifier Comparator, respectively. The output of the differential operational amplifier Comparator is connected to the input of the counter Accumulator via a buffer. The voltage input terminal of the differential ring oscillator Core is connected to the power supply voltage, the ground terminal of the differential ring oscillator Core is connected to ground, and at least one sensing unit is connected in series between the voltage input terminal and the ground terminal of the differential ring oscillator Core.

5. A full CMOS temperature and voltage sensor based on leakage current according to claim 4, characterized in that: In the aforementioned differential ring oscillator (Core), the four differential delay units (DelayCells) are connected end-to-end to form a loop, with the output of one DelayCell connected to the input of the next. Specifically, between the third and fourth differential delay units, the positive and negative differential output ports of the previous DelayCell are cross-connected with the negative and positive differential output ports of the next DelayCell. Each pair of differential delay units (DelayCells) is connected by corresponding positive and negative differential output ports of the previous and subsequent differential delay units (DelayCells). The positive and negative differential output ports of the fourth differential delay unit (DelayCell) are used as the two output terminals of the differential ring oscillator (Core), which are then connected to the non-inverting and inverting input terminals of the differential operational amplifier (Comparator), respectively. The voltage input terminals and ground terminals of the four differential delay units (DelayCells) are connected to the power supply voltage and ground, respectively.

6. A full CMOS temperature and voltage sensor based on leakage current according to claim 5, characterized in that: The sensing units are all mainly composed of a MOS transistor. The source and gate of the MOS transistor are shorted, the drain of the MOS transistor is connected to the differential ring oscillator Core, and the source of the MOS transistor is connected to the power supply voltage or ground.

7. A full CMOS temperature and voltage sensor based on leakage current according to claim 1, characterized in that: In the processor, the voltage count value is corrected based on the division result between the temperature count value and the reference count value to obtain an accurate voltage; At the same time, the temperature count value is corrected based on the division result between the voltage count value and the reference count value to obtain an accurate temperature.

8. A full CMOS temperature and voltage sensor based on leakage current according to claim 1, characterized in that: The voltage count is corrected by dividing the temperature count value by the reference count value to obtain an accurate voltage. Specifically, the correction is performed according to the following formula: ， in, This represents the voltage-sensing oscillator count value. This indicates the set reference oscillator count value, and U represents the final voltage data.

9. A full CMOS temperature and voltage sensor based on leakage current according to claim 1, characterized in that: The temperature count is corrected by dividing the voltage count value by the reference count value to obtain an accurate temperature. Specifically, the correction is performed according to the following formula: ， in, This represents the count value of the temperature-sensing oscillator. This represents the set reference oscillator count value, and T represents the final temperature data.

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