CN112013991A

CN112013991A - Temperature measuring circuit based on standard unit

Info

Publication number: CN112013991A
Application number: CN202010794616.6A
Authority: CN
Inventors: 樊凌雁; 毛楷仁; 刘海銮
Original assignee: Hangzhou Dianzi University
Current assignee: Hangzhou Dianzi University
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2020-12-01

Abstract

The invention discloses a temperature measuring circuit based on standard units, which comprises a time delay circuit, a counter, a reference clock and a temperature calculating unit, wherein the time delay circuit comprises a plurality of standard units which are connected in series; the frequency of the reference clock is determined according to the time delay time of the input signal and the output signal of the time delay circuit, and the reference clock has at least one square wave in the time delay time; the input of the counter is connected with the input signal of the time delay circuit, the output signal of the time delay circuit and the reference clock; the temperature calculating unit is connected with the output of the counter, and the real-time temperature is obtained according to a relation function or a relation table of the time delay time and the temperature of the standard unit in the time delay circuit. The circuit is designed based on the standard unit, the circuit can be conveniently integrated in a chip, other temperature sensing chips, driving circuits and the like do not need to be additionally built, the time for constructing the circuit is greatly reduced, and the complexity of the circuit is greatly reduced.

Description

Temperature measuring circuit based on standard unit

Technical Field

The invention belongs to the field of chips, and relates to a temperature measuring circuit based on a standard unit.

Background

The chip has extremely high temperature requirements in operation, which requires that the chip must be designed with consideration of detecting the operating temperature of the chip and feeding the chip back to adjust the operating frequency of the chip.

The specific methods in the prior art are as follows: calculating by using a classical junction temperature equation; a method of applying a thermocouple is used; the case temperature outside the package was measured using an infrared camera. In addition to the above methods, the current mainstream method is to use the relationship among the resistor, the voltage signal and the temperature, and add a designed temperature measuring circuit including a phase-voltage converter, a voltage controlled oscillator, a frequency-generator, etc. to complete the measurement of the chip temperature.

The prior art has the following defects: the error is extremely large; may be used for larger packages, but not for smaller packaged devices; infrared cameras are extremely costly, on the order of tens of thousands of dollars.

The prior art has extremely high requirements on signals, and for different signals, if the requirements are different, the purposes are different, the structure of the circuit must be changed, and the plate must be made again, which raises the cost to a certain extent, and the circuit design is complicated. Because of this characteristic, it is not easy to apply to other systems and has poor portability.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a temperature measuring circuit based on standard cells.

Comprising a delay circuit, a counter, a reference clock and a temperature calculation unit, wherein,

the time delay circuit comprises a plurality of standard units which are connected in series; the frequency of the reference clock is determined according to the time delay time of the input signal and the output signal of the time delay circuit, and the reference clock has at least one square wave in the time delay time; the input of the counter is connected with the input signal of the time delay circuit, the output signal of the time delay circuit and the reference clock; the temperature calculating unit is connected with the output of the counter, and the real-time temperature is obtained according to a relation function or a relation table of the time delay time and the temperature of the standard unit in the time delay circuit.

Preferably, the standard unit is an and gate.

Preferably, the standard cell is a not gate.

Preferably, the standard cell is an inverter.

Preferably, the delay time of the delay circuit is calculated by transmitting the number of the sampled clocks to the temperature calculating unit after the counter finishes counting, obtaining the delay time t according to the number of the sampled clocks and the frequency of the reference clock,

f＝1/T；

t＝T/N；

wherein f is the frequency of the reference clock, T is the period of the reference clock, and N is the number of clocks sampled by the counter.

Compared with the prior art, the invention has the beneficial effects that: the circuit designed for using the standard unit can be conveniently integrated in a chip, other temperature sensing chips, driving circuits and the like do not need to be additionally built, the time for constructing the circuit is greatly reduced, and the complexity of the circuit is greatly reduced.

The invention is easy to standardize, has simple and convenient design, can be directly transplanted and used aiming at different chips, and reduces the cost to a certain extent. A temperature measuring circuit which can be integrated in a chip is designed according to the principle of the relation between the time delay and the temperature of a standard unit, the temperature of the chip is monitored in real time, and the chip can adjust the proper working frequency of the chip in the temperature environment according to the returned temperature value.

Drawings

FIG. 1 is a block diagram of a standard cell based temperature measurement circuit according to an embodiment of the present invention;

FIG. 2 is a signal diagram of a delay circuit of a standard cell based temperature measurement circuit according to an embodiment of the present invention;

FIG. 3 is a waveform diagram of the delay time and the reference clock of the delay circuit of the standard cell based temperature measurement circuit according to the embodiment of the present invention;

FIG. 4 is a schematic diagram of a delay circuit of a standard cell based temperature measurement circuit according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a relationship between standard cell delay time and temperature of the delay circuit of the standard cell-based temperature measurement circuit according to the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

On the contrary, the invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.

An embodiment of the invention, see fig. 1, comprises a delay circuit 10, a counter 20, a reference clock 30 and a temperature calculation unit 40, wherein,

the delay circuit 10 comprises a plurality of standard cells 11 connected in series; the frequency of the reference clock 30 is determined according to the delay time of the input signal and the output signal of the delay circuit 10, and within the delay time, the reference clock 30 has at least one square wave; the input of the counter 20 is connected with the input signal of the delay circuit 10, the output signal of the delay circuit 10 and the reference clock 30; the temperature calculating unit 40 is connected to the output of the counter 20, and obtains the real-time temperature according to the relation function or relation table of the delay time and the temperature of the standard unit 11 in the delay circuit 10.

In the embodiment, the standard cell 11 is an and gate, a not gate or an inverter.

The temperature measuring circuit of the present invention is further integrated in a system-on-chip, wherein the delay circuit 10, see fig. 4, is formed by connecting N standard cells 11 in series, when measuring temperature, a signal is input into the delay circuit 10, and in the delay circuit 10, the delay time of each standard cell 11 has a functional relationship with temperature. Referring to fig. 2 schematically, the sig1 is a signal input by the control unit, and since the delay of the conductive wire is negligible, the signal of the sig3 can be regarded as a signal of the sig1, and the signal of the sig2 is a signal of the sig1 after a time delay after the signal enters the delay circuit 10.

The signal of sig3 is firstly input into the counter 20, the counter 20 starts counting, after a period of time (ns), the sig2 signal is also input into the counter 20 to stop counting by the counter 20, a reference clock 30 is needed in advance to sample the period of time, the reference clock 30 can be of any frequency, the faster the frequency is, the more accurate the subsequent temperature calculation is, and if the time is not fast enough, the counter 20 can acquire the time delay by increasing the number of standard cells 11 in fig. 4. Waveform diagram referring to fig. 3, the more square waves of the reference clock 30 in the time delay, the more accurate the calculation. We need to ensure that there is at least one square wave in the time delay, and if there is no square wave, the time delay can be collected by the reference clock 30 by increasing the standard cell 11 to increase the time delay. The standard cells 11 can be added freely, so that the more the standard cells are added, the longer the delay is, and the time delay can be collected by the counter 20.

The delay time of the delay circuit 10 is calculated by transmitting the number of the sampled clocks to the temperature calculating unit 40 after the counter 20 finishes counting, obtaining the delay time t according to the number of the sampled clocks and the frequency of the reference clock 30,

f＝1/T；

t＝T/N；

where f is the frequency of the reference clock 30, T is the period of the reference clock 30, and N is the number of clocks sampled by the counter 20. The current temperature of the chip can be obtained through the mapping relation between the time delay time and the temperature, and the temperature is transmitted back to the central processing unit, so that the chip adjusts the working frequency of the chip according to the specific temperature to adapt to the current condition.

The delay of each unit of standard cell 11 for transmitting data has a proportional relationship with temperature, because the standard cell 11 is not unique, and optionally has an and gate, a not gate, an inverter, etc., and their delays all satisfy a functional relationship of f (T) T, where T is temperature and T is the delay of the standard cell 11 for transmitting data. The relationship is schematically shown in FIG. 5.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A standard cell based temperature measurement circuit comprising a delay circuit, a counter, a reference clock and a temperature calculation unit, wherein,

2. The standard cell based temperature measurement circuit of claim 1, wherein the standard cell is an and gate.

3. The standard cell based temperature measurement circuit of claim 1, wherein the standard cell is a not gate.

4. The standard cell based temperature measurement circuit of claim 1, wherein the standard cell is an inverter.

5. The standard cell-based temperature measurement circuit of claim 1, wherein the delay time of the delay circuit is calculated by transmitting the number of sampled clocks to the temperature calculation unit after the counter finishes counting, obtaining the delay time t according to the number of sampled clocks and the frequency of the reference clock,

f＝1/T；

t＝T/N；