CN203178843U - Temperature compensation system - Google Patents

Abstract

The utility model discloses a temperature compensation system used for temperature compensation for a temperature sensitive circuit in a chip. The temperature compensation system comprises a first resistor, an amplifier circuit and a field effect tube, wherein one end of the first resistor is connected with one end of a large-power-consumption circuit in the chip, the other end of the large-power-consumption circuit in the chip is connected with the ground, the other end of the first resistor is connected with an external power supply, two input ends of the amplifier circuit are correspondingly connected with two ends of the first resistor respectively, the output end of the amplifier circuit is connected with the grid electrode of the field effect tube, the source electrode of the field effect tube is connected with the external power supply, and the drain electrode of the field effect tube is connected with the chip. When a work state of the chip changes, the temperature compensation system can effectively carry out the temperature compensation on the temperature sensitive circuit in the chip, so that stable transition of the chip in work states can be achieved and work performance and precision of the chip are improved.

Description

Temperature-compensated system

Technical field

The utility model relates to integrated circuit fields, relates more specifically to a kind of temperature-compensated system of the chip internal circuit being carried out temperature compensation.

Background technology

As everyone knows, chip can be divided into big power digital circuit and temperature-sensitive circuit usually by its function its internal circuit module, and this two circuit cooperatively interacts to realize and finish the function of chip itself.Wherein, chip its duty in the course of the work can change, and big power digital circuit power consumption when chip operation is bigger, and its power consumption can change along with the variation of chip operation state simultaneously, and the chip internal variation of temperature is mainly produced by big power digital circuit; Temperature-sensitive circuit then can be because its duty of chip internal variation of temperature changes, i.e. the variation of the power consumption that produces because of big power digital circuit may make the temperature-sensitive circuit job insecurity, need carry out temperature compensation to temperature-sensitive circuit.

Usually, chip operation is at least two kinds of different states, and after the duty of chip changed, the power consumption of big power digital circuit also can change, thereby causes chip temperature also along with variation; This temperature variation will inevitably exert an influence to temperature-sensitive circuit, thereby causes its performance to change, and the oscillation frequency such as meeting change pierce circuit changes the output current of reference current etc.

Now in the technology, usually in the design process of chip, can carry out the temperature compensation design to temperature-sensitive circuit, but this Compensation Design is not considered the temperature variation brought after the chip operation state switches, influence to temperature-sensitive circuit, and this influence is in the design higher to the precision of chip and performance requirement, and this influences serviceability and the precision of entire chip significantly.

Therefore, be necessary to provide a kind of improved temperature-compensated system that the chip internal circuit is carried out temperature compensation to overcome above-mentioned defective.

The utility model content

The purpose of this utility model provides a kind of temperature-compensated system, when described temperature-compensated system changes when the chip operation state, can be effectively the temperature-sensitive circuit of chip internal be carried out temperature compensation, make transition reposefully between chip in working order, improved serviceability and the degree of accuracy of chip.

For achieving the above object, the utility model provides a kind of temperature-compensated system, be used for the temperature-sensitive circuit of chip internal is carried out temperature compensation, described temperature-compensated system comprises first resistance, amplifying circuit, and field effect transistor, one end of described first resistance links to each other with an input end and the external power source of described amplifying circuit respectively, the other end of described first resistance respectively with another input end of described amplifying circuit, one end of the big power digital circuit of chip internal links to each other, the other end ground connection of described big power digital circuit, the output terminal of described amplifying circuit links to each other with the grid of described field effect transistor, the source electrode of described field effect transistor is connected with external power source, and the drain electrode of described field effect transistor links to each other with an end of described temperature-sensitive circuit, the other end ground connection of described temperature-sensitive circuit.

Preferably, described amplifying circuit comprises second resistance, the 3rd resistance and operational amplifier, described second resistance, one end is connected with the other end of described first resistance, the other end of described second resistance is connected with the reverse input end of described operational amplifier, the positive input of described operational amplifier is connected with the other end of described first resistance, the output terminal of described operational amplifier is connected with the grid of described field effect transistor, and the two ends of described the 3rd resistance are connected with reverse input end and the output terminal thereof of described operational amplifier respectively.

Preferably, described the 3rd resistance is rheostat.

Compared with prior art, temperature-compensated system of the present utility model changes by the electric current of the big power digital circuit of described first resistance detection, and the change of power consumption of described big power digital circuit is synchronized with the variation of its electric current, make how described first resistance detects the change of power consumption of described big power digital circuit exactly, also namely detect the variation of the duty of described chip, described amplifying circuit amplifies the voltage at the described first resistance two ends is corresponding, and the voltage transitions after will amplifying by described field effect transistor is electric current, and the electric current after described field effect transistor will be changed inputs to the temperature-sensitive circuit of chip internal, thereby temperature-sensitive circuit is carried out temperature compensation, make transition reposefully between chip in working order, improved serviceability and the degree of accuracy of chip.

By following description also by reference to the accompanying drawings, it is more clear that the utility model will become, and these accompanying drawings are used for explaining the utility model.

Description of drawings

Fig. 1 is the structural representation that the utility model temperature-compensated system is connected with the chip internal circuit.

Embodiment

With reference now to accompanying drawing, describe embodiment of the present utility model, the similar elements label represents similar elements in the accompanying drawing.As mentioned above, the utility model provides a kind of temperature-compensated system, when described temperature-compensated system changes when the chip operation state, can be effectively the temperature-sensitive circuit of chip internal be carried out temperature compensation, make transition reposefully between chip in working order, improved serviceability and the degree of accuracy of chip.

Please refer to Fig. 1, Fig. 1 is the structural representation that the utility model temperature-compensated system is connected with the chip internal circuit.Temperature-compensated system of the present utility model is used for the temperature-sensitive circuit of chip internal is carried out temperature compensation, and described temperature-compensated system comprises first resistance R 1, amplifying circuit and field effect transistor M1; One end of described first resistance R 1 is connected with an end of the big power digital circuit of chip internal, and the other end ground connection of the big power digital circuit of chip internal, the other end of described first resistance R 1 is connected with external power source VCC, described first resistance R 1 changes for detection of the electric current of big power digital circuit, because the working temperature of chip internal is directly proportional with the power consumption of big power digital circuit, and being connected as can be known by described first resistance R 1 and big power digital circuit, the power consumption of big power digital circuit is directly proportional with the electric current that flows through on it, get final product the variation of detection chip internal temperature, also get final product the variation of detection chip duty; Two input ends of described amplifying circuit are corresponding respectively to be connected with the two ends of described first resistance R 1, in practical application of the present utility model, for guaranteeing that external power source VCC provides its operate as normal required voltage for big power digital circuit, the resistance of described first resistance R 1 is less, thereby make that the magnitude of voltage on described first resistance R 1 is also less, can not satisfy the requirement to the temperature compensation of temperature-sensitive circuit, thereby described amplifying circuit amplifies the voltage scale at described first resistance R 1 two ends; The output terminal of described amplifying circuit is connected with the grid of described field effect transistor M1, thereby the voltage after described amplifying circuit will amplify inputs to the grid of described field effect transistor M1; The source electrode of described field effect transistor M1 is connected with external power source VCC, its drain electrode is connected with an end of the temperature-sensitive circuit of chip internal, and the other end ground connection of the temperature-sensitive circuit of chip internal, thereby described field effect transistor M1 is electric current and temperature-sensitive circuit is carried out temperature compensation with the voltage transitions of described amplifying circuit output, avoided the variation because of the chip operation state, made the power consumption of big power digital circuit change and cause the instability of temperature-sensitive circuit work.

Particularly, the amplifying circuit of temperature-compensated system of the present utility model comprises second resistance R 2, the 3rd resistance R 3 and operational amplifier OP; One end of described second resistance R 2 is connected with the other end of described first resistance R 1, the other end of described second resistance R 2 is connected with the reverse input end of described operational amplifier OP, the positive input of described operational amplifier OP is connected with an end of described first resistance R 1, the output terminal of described operational amplifier OP is connected with the grid of described field effect transistor M1, and the two ends of described the 3rd resistance R 3 are connected with reverse input end and the output terminal thereof of described operational amplifier OP respectively; Described the 3rd resistance R 3 adds that with the ratio of described second resistance R 21 is the enlargement factor of described operational amplifier OP, thereby in the concrete application of the utility model temperature-compensated system, can carry out positive temperature compensation repayment according to the temperature-sensitive circuit needs of concrete chip is that the subzero temperature compensation selects to have the 3rd resistance R 3 and second resistance R 2 of corresponding ratio, carry out corresponding temperature compensation with the temperature-sensitive circuit to chip internal, when changing because duty changes with assurance chip internal temperature, the work that temperature-sensitive circuit still can be normal and stable; In preferred implementation of the present utility model, described the 3rd resistance R 3 is rheostat, thereby when temperature-compensated system of the present utility model is applied on the different chips, do not need corresponding selection to change second resistance R 2 or the 3rd resistance R 3, only need the resistance of described the 3rd resistance R 3 of corresponding adjusting to carry out corresponding temperature compensation to the temperature-sensitive circuit of different chips, improved use dirigibility and the usable range of described temperature-compensated system.

The principle of work of the utility model temperature-compensated system is described below in conjunction with Fig. 1:

Because it is the main cause that causes that chip temperature changes that the working current of chip changes, be specially when the chip operation state changes, when the working current of chip raise, chip temperature raise, and when its working current reduced, chip temperature reduced; So temperature variation for detection chip, but the variation of detection chip working current, because changing, the chip operation electric current mainly concentrates on power digital circuit greatly again, and described first resistance R 1 is connected between external power source VCC and the big power digital circuit, so can detecting the electric current of big power digital circuit, described first resistance R 1 changes, and the voltage at described first resistance R 1 two ends is proportional to the electric current that it flows through described first resistance R 1, i.e. the variation of the voltage at described first resistance R 1 two ends is the variation of the electric current that flows through on it.As shown in Figure 1, establishing the electric current that flows through described first resistance R 1 is It, and the voltage at big power digital circuit two ends is Vt, and the resistance of described first resistance R 1 is Rt,

VCC-Vt＝It*Rt （1）

(1) It*Rt is that the voltage at described first resistance R 1 two ends is in the formula, and for fear of the operate as normal of the big power digital circuit of influence, the resistance of described first resistance R 1 is less, thereby the voltage at described first resistance R 1 two ends is generally less, need amplify it; Form a high-precision amplifying circuit by described second resistance R 2, described the 3rd resistance R 3 and described operational amplifier OP, the voltage at described first resistance R 1 two ends is amplified; If the resistance of described second resistance R 2 is Re, the resistance of establishing described the 3rd resistance R 3 is k*R, and wherein k is the adjustment factor of described the 3rd resistance R 3, because described the 3rd resistance R 3 is rheostat, the amplification coefficient Aop of this amplifying circuit is:

$\mathrm{Aop}=\frac{k*R}{\mathrm{Re}}+1---\left(2\right)$

By (2) formula as can be known, regulate the resistance of described the 3rd resistance R 3, just can regulate the amplification coefficient Aop of amplifying circuit.

The output voltage V g that can obtain described operational amplifier OP according to (1), (2) formula is:

$\mathrm{Vg}=(\frac{k*R}{\mathrm{Re}}+1)*(\mathrm{VCC}-\mathrm{Vt})$

Because the output voltage V g of operational amplifier OP is the grid voltage of described field effect transistor M1, if the breadth length ratio of described field effect transistor M1 is W/L, its threshold voltage is Vth, definition up is the electron mobility of described field effect transistor M1, Cox is the grid specific capacitance of described field effect transistor M1, and then the offset current Ic of described field effect transistor M1 generation is:

$\mathrm{Ic}=\frac{1}{2}\mathrm{up}*\mathrm{Cox}*\frac{W}{L}*{((\frac{k*R}{\mathrm{Re}}+1)*(\mathrm{VCC}-\mathrm{Vt})-\mathrm{Vth})}^2---\left(3\right)$

In (3) formula, because VCC-Vt is the magnitude of voltage at described first resistance R 1 two ends, this magnitude of voltage is directly proportional with chip operation electric current (being the working current of big power digital circuit), and the chip operation electric current is directly proportional with the chip operation temperature, so can obtain VCC-Vt is directly proportional with temperature, because the threshold voltage vt h of field effect transistor M1 also is directly proportional with temperature, then at polynomial expression

$(\frac{k*R}{\mathrm{Re}}+1)*(\mathrm{VCC}-\mathrm{Vt})-\mathrm{Vth}---\left(4\right)$

In temperature coefficient can be positive temperature or subzero temperature, be specially and work as

Positive temperature coefficient during greater than the temperature coefficient of VCC-Ct, then (4) formula is positive temperature, when

Positive temperature coefficient during less than the temperature coefficient of VCC-Ct, then (4) formula is subzero temperature.Because

Temperature coefficient can change by the resistance of regulating described the 3rd resistance R 3, so the temperature coefficient of the offset current Ic of the generation of described field effect transistor M1 can be regulated by described the 3rd resistance R 3, namely can be positive temperature compensation and repay electric current, also can be the subzero temperature offset current.Be specially, when the temperature characterisitic of temperature-sensitive circuit is positive temperature, then can provide the offset current of subzero temperature characteristic to it by the drain electrode of described field effect transistor M1, to offset owing to chip temperature changes the influence that brings, otherwise, when the temperature characterisitic of temperature-sensitive circuit is subzero temperature, then can provide the offset current of positive temperature characteristics to it by the drain electrode of described field effect transistor M1, to offset owing to chip temperature changes the influence that brings.

Abovely in conjunction with most preferred embodiment the utility model is described, but the utility model is not limited to the embodiment of above announcement, and should contains various modification, equivalent combinations of carrying out according to essence of the present utility model.

Claims (3)

1. temperature-compensated system, be used for the temperature-sensitive circuit of chip internal is carried out temperature compensation, it is characterized in that, comprise first resistance, amplifying circuit, and field effect transistor, one end of described first resistance links to each other with an input end and the external power source of described amplifying circuit respectively, the other end of described first resistance respectively with another input end of described amplifying circuit, one end of the big power digital circuit of chip internal links to each other, the other end ground connection of described big power digital circuit, the output terminal of described amplifying circuit links to each other with the grid of described field effect transistor, the source electrode of described field effect transistor is connected with external power source, and the drain electrode of described field effect transistor links to each other with an end of described temperature-sensitive circuit, the other end ground connection of described temperature-sensitive circuit.

2. temperature-compensated system as claimed in claim 1, it is characterized in that, described amplifying circuit comprises second resistance, the 3rd resistance and operational amplifier, described second resistance, one end is connected with an end of described first resistance, the other end of described second resistance is connected with the reverse input end of described operational amplifier, the positive input of described operational amplifier is connected with the other end of described first resistance, the output terminal of described operational amplifier is connected with the grid of described field effect transistor, and the two ends of described the 3rd resistance are connected with reverse input end and the output terminal thereof of described operational amplifier respectively.

3. temperature-compensated system as claimed in claim 2 is characterized in that, described the 3rd resistance is rheostat.

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