Temperature sensor

1. A temperature sensor comprising:

a NAND gate; and

K delay units;

wherein:

the NAND gate comprises a first and a second input terminals and an output terminal;

the first input terminal is coupled to an external starting control signal;

the K delay units are connected in series;

an input end of the first delay unit is connected to the output terminal of the NAND gate;

an output end of a last delay unit among the K delay units is connected to the second input terminal of the NAND gate;

K is an even number greater than 0;

each delay unit comprises n stage inverters in series, wherein n is an odd number greater than 1;

for each delay unit, an output end of a former stage inverter is connected with an input end of a latter stage inverter, each stage inverter is connected with a PMOS transistor and an NMOS transistor to control the each stage inverter in an on-state or an off-state, wherein the PMOS transistor and the NMOS transistor connected with an i-th stage inverter are referred to as M Pi and M Ni , respectively; and

a source end of the M Ni is connected to GND, a drain end of the M Ni is connected to the i-th stage inverter, a gate electrode of the M Ni is connected to a signal line V Ni , a drain end of the M Pi is connected to the i-th stage inverter, a source end of the M Pi is connected to a power supply, a gate electrode of the M Pi is connected to a signal line V Pi , and a substrate end of the M Pi is connected to a signal line V PB .

2. The temperature sensor of claim 1 , wherein every delay unit of the temperature sensor has a same number of inverters.

3. The temperature sensor of claim 2 , wherein gate electrodes of same stage NMOS transistors in the delay units are connected to one signal line, and the signal line V Ni with same value of i in all delay units are controlled with a same signal line.

4. The temperature sensor of claim 2 , wherein gate electrodes of same stage PMOS transistors in the delay units are connected to one signal line, and the signal lines V Pi with the same value of i in all delay units are controlled with a same signal line.

5. A method for supply voltage measurement with the temperature sensor of claim 1 , comprising controlling the temperature sensor in a voltage-mode and obtaining a supply voltage through measuring an output frequency of the temperature sensor;

wherein:

the voltage-mode refers to: controlling all the PMOS transistors and NMOS transistors in each delay unit of the temperature sensor to be in on-state.

6. A method for temperature measurement calibration with the temperature sensor of claim 1 , wherein in a voltage-mode, the method comprises measuring an output frequency of the temperature sensor to obtain the supply voltage, and the supply voltage is configured for calibration of temperature measurement in P-mode or N-mode.

7. A method for supplying voltage calibration with the temperature sensor of claim 1 , comprising:

obtaining temperature values in P-mode and N-mode respectively; and

calibrating voltage measurement in a voltage mode with the temperature values measured in the P-mode and/or the N-mode.

8. A method for process corner evaluation with the temperature sensor of claim 1 , comprising:

applying a known voltage to the temperature sensor;

control the temperature sensor in a voltage-mode; and

evaluating process corners through an output distribution of different chips.

9. A test system comprising the temperature sensor of claim 1 , wherein the temperature sensor is configured to monitor a temperature of the test system.

10. The test system of claim 9 , further comprising a device or chip undergoing heat management.

11. The test system of claim 9 , further comprising a device or chip undergoing supply voltage measurement.

12. The test system of claim 9 , further comprising a device or chip for evaluating process corners.

13. A method for temperature measurement with a temperature sensor,

the temperature sensor comprising:

a NAND gate; and

K delay units;

wherein:

the NAND gate comprises a first and a second input terminals and an output terminal;

the first input terminal is coupled to an external starting control signal;

the K delay units are connected in series;

an input end of the first delay unit is connected to the output terminal of the NAND gate;

an output end of a last delay unit among the K delay units is connected to the second input terminal of the NAND gate;

K is an even number greater than 0;

each delay unit comprises n stage inverters in series, wherein n is an odd number greater than 1;

each stage inverter is connected with a PMOS transistor and an NMOS transistor to control the each stage inverter in an on-state or an off-state; and

the method comprising:

an output frequency of the temperature sensor in P-mode or N-mode is measured to obtain a temperature value; wherein:

the P-mode refers to: for the temperature sensor, the NMOS transistors in each delay unit are in on-state, one of the PMOS transistors in each delay unit is in off-state, and the other PMOS transistors in each delay unit are in on-state; and

the N-mode refers to: for the temperature sensor, the PMOS transistors in each delay unit are in on-state, and one of the NMOS transistors in each delay unit is in off-state, and the other NMOS transistors in each delay unit are in on-state.

14. The method for temperature measurement of claim 4 , wherein inverters of the K delay units functioning in leakage states are same stage inverters.

15. The method for temperature measurement of claim 13 , wherein a measuring procedure of the P-mode further comprises:

P1, for each delay unit of the temperature sensor, control all the NMOS transistors in on-state, one of the PMOS transistors M Pi in off-state, and the other PMOS transistors in on-state, then measure the temperature value T Pi through the temperature sensor;

P2, repeat the P1 step with traversing the value of variable i, and a corresponding temperature value T Pi is obtained respectively, i is an integer and i∈[1, n];

P3, take an average value of the temperature value T Pi as a final value of temperature.

16. The method for temperature measurement of claim 13 , wherein a measuring procedure of N-mode further comprises:

N1, for each delay unit of the temperature sensor, control all the PMOS transistors in on-state, one of the NMOS transistors M Ni in off-state, and the other NMOS transistors in on-state, then measure the temperature value T Ni through the temperature sensor;

N2, repeat the N1 step with traversing the value of variable i, and the corresponding temperature value T Ni can be obtained respectively, i is an integer and i∈[1, n];

N3, take an average value of the temperature value T Ni as a final value of temperature.

17. An apparatus comprising a temperature sensor, wherein

the temperature sensor comprises:

a NAND gate; and

K delay units;

wherein:

the NAND gate comprises a first and a second input terminals and an output terminal;

the first input terminal is coupled to an external starting control signal;

the K delay units are connected in series;

an input end of the first delay unit is connected to the output terminal of the NAND gate;

an output end of a last delay unit among the K delay units is connected to the second input terminal of the NAND gate;

K is an even number greater than 0;

each delay unit comprises n stage inverters in series, wherein n is an odd number greater than 1;

each stage inverter is connected with a PMOS transistor and an NMOS transistor to control the each stage inverter in an on-state or an off-state; and

the temperature sensor is configured to realize conversion from temperature to current based on a relationship between leakage current of MOS transistors and temperature, and further realize conversion from current to frequency based on a ring oscillator structure, so as to realize digital output of temperature measurement.

18. The apparatus of claim 17 , wherein the temperature sensor is configured to function in a temperature range of −40˜125° C. and under a digital power supply of less than 1V, having an accuracy of better than 2° C.

19. The apparatus of claim 17 , wherein the temperature sensor is an all-digital, reconfigurable temperature sensor.