CN101650997A - Resistor and circuit using same - Google Patents

Abstract

The invention discloses a resistor, which can be applied to a constant current source generator or a temperature compensating circuit used for performing temperature compensation on a constant voltagereference circuit, and comprises at least one first resistor and at least one second resistor. The second resistor is coupled to the first resistor; and one of the first resistor and the second resistor has the characteristic of a negative temperature coefficient, while the other has the characteristic of a positive temperature coefficient. The resistance value of the resistor can achieve the effect of being not affected by the temperature relatively by using the opposite temperature characteristics of first resistor and the second resistor.

Description

Resistor and use the circuit of this resistor

Technical field

The present invention relates to a kind of resistance, be meant a kind of resistor especially with temperature compensation characteristic.

Background technology

Produced circuit or decided in the reference circuits at constant current source in the past, in order to export a stable and curtage of temperature influence not, temperature-compensating is done at the metal-oxide half field effect transistor in the circuit (MOS) or two junction transistor active members such as (BJT) by big city.In other words, with the constant current source generation circuit 9 of Fig. 1, its output current is to be inversely proportional to the electron drift rate μ of active member and the product of resistance, but the electron drift rate μ of active member understands temperature influence and changes.So when electron drift rate μ descends along with the temperature rising, to make output current rise with temperature, therefore way in the past is to adopt the resistance with positive temperature coefficient, compensate the output current deviation that the electron drift rate μ of active member is caused, that is to say when temperature rises, though output current can descend with electron drift rate μ and rise, output current is descended, and like this one increases one subtracts and makes constant current source generator 9 can produce a more stable electric current.

But, in above-mentioned circuit in the past, though can utilize resistance to go to compensate active member because the output current deviation that the electron drift rate is caused with positive temperature coefficient, but owing to only use single resistance, possibly because resistance varies with temperature excessive, and to the output current deviation overcompensation of active member, and make output current (or voltage) still can't tend towards stability.

Summary of the invention

The objective of the invention is at the resistor that a kind of temperature characterisitic that can compensating resistance is provided and use the circuit of this resistor.

Resistor of the present invention is to comprise at least one first resistance and at least one second resistance.This second resistance is coupled to first resistance, and first resistance and second resistance one of them have the characteristic of negative temperature coefficient, wherein another has the characteristic of positive temperature coefficient.

Preferably, resistor of the present invention can be applied in certain current source generator.This constant current source generator is in order to providing certain electric current to a load that couples with it, and comprises a first transistor, a transistor seconds and a resistor.The drain of the first transistor is accepted a reference current and is coupled mutually with gate, and source electrode is ground connection then; The drain of transistor seconds couples the gate that load and gate are coupled to the first transistor, and drain output one and reference current have the electric current of certain proportion relation; Resistor be coupled to the drain of the first transistor and transistor seconds source electrode one of them.

In addition, resistor of the present invention also can be applied to a pair of certain reference circuits and carries out in the temperature-compensation circuit of temperature-compensating.This temperature-compensation circuit comprises a first transistor, a transistor seconds and a resistor.The base stage of the first transistor and collection utmost point ground connection, and emitter-base bandgap grading is coupled to and decides reference circuits and accept a reference current; The base stage of transistor seconds and collection utmost point ground connection, and its emitter-base bandgap grading is coupled to decides reference circuits, and accept one with the proportional electric current of reference current, resistor then be serially connected with the emitter-base bandgap grading of deciding reference circuits and the first transistor and transistor seconds emitter-base bandgap grading one of them.

Beneficial effect of the present invention is: utilize first resistance opposite with the characteristic of second resistance, make the resistance of resistor can have the more not characteristic of temperature influence.

Description of drawings

Fig. 1 is a circuit diagram, and the element relation of the circuit of constant current source generation in the past is described;

Fig. 2 is a circuit diagram, and first preferred embodiment of resistor of the present invention is described;

Fig. 3 is a circuit diagram, and first kind of kenel of resistor of the present invention is described;

Fig. 4 is a simulation drawing, and the analog result of tandem type resistor for variations in temperature is described;

Fig. 5 is a circuit diagram, and second kind of kenel of resistor of the present invention is described;

Fig. 6 is a simulation drawing, and parallel connection type and the mixed type resistor analog result for variations in temperature is described;

Fig. 7 is a circuit diagram, and the third kenel of resistor of the present invention is described;

Fig. 8 is a circuit diagram, and second preferred embodiment of resistor of the present invention is described.

Embodiment

The present invention is described in detail below in conjunction with drawings and Examples:

Consult Fig. 2, first preferred embodiment of resistor of the present invention is resistor 1 to be applied to a constant current source produce circuit 2.Produce in the circuit 2 the first transistor M at constant current source ₁Drain accept one by the 3rd transistor M ₃The reference current I that is exported _REFAnd couple mutually with its gate, source electrode is ground connection then; Transistor seconds M ₂Drain couple one the 4th transistor M ₄And gate is coupled to the first transistor M ₁Gate, source electrode then is connected in series with resistor 1 of the present invention.

It is to utilize the 3rd transistor M that constant current source produces circuit 2 ₃With the 4th transistor M ₄Identical breadth length ratio, produce one with reference current I _REFIdentical decide electric current I _R, i.e. I _REF=I _R, and utilize the 4th transistor M again ₄With the 5th transistor M ₅Identical breadth length ratio produces output current I _OUT(be I _REF=I _R=I _OUT) and offer and the 5th transistor M ₅The load 21 that couples of drain use.

Because the first transistor M ₁With transistor seconds M ₂Gate couple mutually, so

V _GS1＝V _GS2+I _R·R (1)

Wherein R is the resistance of resistor 1, and the electric current of transistor in the saturation region is

I＝1/2μ _nC _oxW/L(V _GS-V _TH) ² (2)

The first transistor M ₁With transistor seconds M ₂The ratio of breadth length ratio be 1: N, i.e. (W/L) _M2=N (W/L) _M1So, the first transistor M ₁Gate to source voltage be

${\mathrm{<figure-callout\; id="1"\; label="V\; GS"\; filenames="A2008101333610012H1.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{GS}}={\left(\frac{2\&CenterDot;I_{\mathrm{OUT}}}{{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}{(W/L)}_{M1}}\right)]}^{1/2}+V_{\mathrm{TH}1}---\left(3\right)$

Transistor seconds M ₂Gate to source voltage be

${\mathrm{<figure-callout\; id="2"\; label="V\; GS"\; filenames="A2008101333610009H2.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{GS}}={\left(\frac{2\&CenterDot;I_{\mathrm{OUT}}}{{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}N{(W/L)}_{M1}}\right)]}^{1/2}+V_{\mathrm{TH}2}---\left(4\right)$

(3) and (4) are brought into (1), can get

${\left[\left(\frac{2\&CenterDot;I_{\mathrm{OUT}}}{{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}{(W/L)}_{M1}}\right)\right]}^{1/2}+{\mathrm{<figure-callout\; id="1"\; label="V\; TH"\; filenames="A2008101333610012H1.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{TH}}={\left(\frac{2\&CenterDot;I_{\mathrm{OUT}}}{{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}N{(W/L)}_{M1}}\right)]}^{1/2}+{\mathrm{<figure-callout\; id="2"\; label="V\; TH"\; filenames="A2008101333610009H2.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{TH}}+I_{\mathrm{OUT}}\&CenterDot;R---\left(5\right)$

After again (5) being rearranged at last, can get

$I_{\mathrm{OUT}}\&ap;\frac{2}{{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}{(W/L)}_{\mathrm{<figure-callout\; id="1"\; label="M"\; filenames="A2008101333610012H1.png"\; state="\{\{state\}\}">M</figure-callout>}1}}\frac{1}{R^2}{(1-\frac{1}{{\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="A2008101333610012H1.png"\; state="\{\{state\}\}">N</figure-callout>}}^{1/2}})}^2---\left(6\right)$

Wherein suppose V _TH1With V _TH2Difference very little.By (6) as can be known, output current I _OUTBe electron drift rate μ with active member _nBe inversely proportional to the product of the resistance R of resistor 1, remaining parameter is all determined by processing procedure factory or designer.

Generally speaking, the temperature characterisitic of resistance just determines after dispatching from the factory from processing procedure factory, and the scientific ﹠ technical corporation in downstream can only be applied at these resistance, and can't change the temperature characterisitic of itself, again from the above, the resistance change of resistance can directly have influence on output current I _OUT, that is to say the resistance of resistance if change, then output current I with temperature _OUTCan't tend towards stability.Therefore, can produce the problem of deviation with temperature change for the resistance that solves general resistance, cooperate and consult Fig. 3, the resistor 1 of present embodiment is formed (to call tandem type resistor 1 in the following text) by second resistance, 12 series connection that first resistance 11 and one with ptc characteristics has negative temperature coefficient feature, utilize positive temperature coefficient of resistance resistance and negative temperature coefficient resistance to compensate mutually, make that the resistance of resistor 1 can be more insensitive for single resistance for variation of temperature, promptly the resistance of resistor 1 varies with temperature and the amplitude that changes is less.

Consult Fig. 4, simulation drawing for present embodiment tandem type resistor 1 temperature characterisitic, the X-axis of this simulation drawing is that the expression temperature changes to 80 degree from-40 degree, Y-axis then is the resistance change of expression tandem type resistor 1, and L1, L2 and L3 then are respectively the analog result of first resistance 11, second resistance 12 and tandem type resistor 1.When temperature rose, first resistance 11 made its resistance to rise with temperature because have the characteristic of positive temperature coefficient; Otherwise the resistance with second resistance 12 of negative temperature coefficient feature then can rise and descend by Yin Wendu, and thus, after the resistance that both change was repealed by implication, the resistance of resistor 1 can more not be acted upon by temperature changes.What deserves to be mentioned is that though the resistance of first resistance 11 and second resistance 12 can be cancelled out each other, its resistance but can mutual superposition on temperature characterisitic, so L3 is that the sum total of first resistance 11 and second resistance, 12 resistances is again divided by the analog result of 2 back gained.

Cooperate and consult Fig. 5 and Fig. 6, the resistor 1 of present embodiment also can be formed (to call parallel connection type resistor 1 in the following text) by first resistance 11 and second resistance, 12 institutes parallel with one another, its principle of cancelling out each other by the resistance of positive and negative temperature coefficient is identical with above-mentioned tandem type resistor, so repeat no more.Fig. 6 is the simulation drawing of parallel connection type resistor 1 temperature characterisitic, by showing as can be known among the figure, parallel connection type resistor 1 (with L3 ' expression) can be smaller than the expected results of first resistance 11 or second resistance 12 mutually for Temperature Influence, and wherein L1, L2 are respectively the analog result of first resistance 11, second resistance 12.

Moreover though the temperature characterisitic of parallel connection type resistor 1 can be better than single first resistance 11 or second resistance 12, its resistance (shown in L3 ') still can rise with temperature.Therefore, if will allow the resistance of resistor 1 can not tend towards stability along with variations in temperature, the resistor 1 of present embodiment can also be tandem type and parallel connection type couple mutually form (to call mixed type resistor 1 in the following text), as shown in Figure 7, wherein, after first resistance 11 and second resistance 12 are parallel with one another, connect with another second resistance 13, its principle is exactly to utilize second resistance 13 with negative temperature coefficient feature to compensate the resistance that parallel connection type resistor 1 is just changing with temperature more again.Cooperate and consult Fig. 6, curve L3 wherein " be the analog result of mixed type resistor 1 temperature characterisitic; and by finding among the figure; the resistance of mixed type resistor 1 is spent to 80 degree from temperature-40 and nearly all remained on 6K Ω, the characteristic of its temperature also can be improved many than single first resistance 11 or second resistance 12.

Consult Fig. 8, second preferred embodiment of resistor of the present invention is that resistor 1 is applied to deciding in the temperature-compensation circuit 4 that reference circuits 3 carries out temperature-compensating.This temperature-compensation circuit 4 comprises a first transistor Q ₁, a transistor seconds Q ₂And resistor 1 of the present invention.The first transistor Q ₁Base stage and collection utmost point ground connection, and emitter-base bandgap grading is coupled to and decides reference circuits 3 and accept a reference current I _REFTransistor seconds Q ₂Base stage and collection utmost point ground connection, and emitter-base bandgap grading is coupled to and decides reference circuits 3, and export one with reference current I _REFProportional electric current, and resistor 1 is serially connected with and decides reference circuits 3 and transistor seconds Q ₂Emitter-base bandgap grading between.The resistor 1 of present embodiment is identical with first preferred embodiment, has tandem type, parallel connection type and three kinds of kenels of mixed type, and its operation and principle are also all same as described above, so repeat no more.

Importantly, the temperature characterisitic of resistor 1 of the present invention can change according to user's demand, do not exceed with three kinds of mentioned kenels of the foregoing description, producing circuit 2 with constant current source is example, and the temperature characterisitic of resistor 1 need cooperate the electron drift rate μ of active member _n, because electron drift rate μ _nCan be with temperature just present and change, so the temperature characterisitic of resistor 1 just need be designed to be directly proportional (positive temperature coefficient) with variation of temperature, thus, constant current source generation circuit 2 could be exported the stable electric current of deciding.

In sum, by first resistance with positive temperature coefficient and second resistance with positive temperature coefficient, compensate the temperature characterisitic of resistor of the present invention, not only improved the problem that in the past can't change the temperature characterisitic of resistance itself, and be applied to constant current source and produce circuit or decide reference circuits, can make it produce stable deciding electric current or decide voltage.

Claims (16)

1. resistor is characterized in that:

This resistor comprises:

At least one first resistance; And

At least one second resistance is coupled to this first resistance, and this first resistance and this second resistance one of them have the characteristic of negative temperature coefficient, wherein another has the characteristic of positive temperature coefficient.

2. resistor as claimed in claim 1 is characterized in that: this resistor is to be applied to a pair of certain reference circuits carry out in the temperature-compensation circuit of temperature-compensating.

3. resistor as claimed in claim 1 is characterized in that: this resistor is to be applied in certain current source generator.

4. resistor as claimed in claim 1 is characterized in that: the quantity of this first resistance and this second resistance respectively is one, and series connection each other.

5. resistor as claimed in claim 1 is characterized in that: the quantity of this first resistance and this second resistance respectively is one, and in parallel each other.

6. resistor as claimed in claim 1 is characterized in that: the quantity of this first resistance is one, and the quantity of this second resistance is two, this first resistance and these second resistance one of them in parallel after, wherein another is connected with these second resistance again.

7. a constant current source produces circuit, and in order to provide certain electric current to a load that couples with it, this constant current source produces circuit and comprises:

One the first transistor, its drain are accepted a reference current and are coupled mutually with gate, and its source ground;

One transistor seconds, its drain couple the gate that this load and gate are coupled to this first transistor, and this drain output one and this reference current have the electric current of certain proportion relation; And

One resistor, its be coupled to the drain of this first transistor and this transistor seconds source electrode one of them;

It is characterized in that:

This resistor comprises:

At least one first resistance; And

At least one second resistance is coupled to this first resistance, and this first resistance and this second resistance one of them have the characteristic of negative temperature coefficient, wherein another has the characteristic of positive temperature coefficient.

8. constant current source as claimed in claim 7 produces circuit, it is characterized in that: this a resistor wherein end is coupled to the drain of this first transistor, and wherein the other end is accepted this reference current, and the source ground of this transistor seconds.

9. constant current source as claimed in claim 7 produces circuit, it is characterized in that: this a resistor wherein end is coupled to the source electrode of this transistor seconds, and other end ground connection wherein.

10. constant current source as claimed in claim 7 produces circuit, and it is characterized in that: the quantity of this first resistance and this second resistance respectively is one, and series connection each other.

11. constant current source as claimed in claim 7 produces circuit, it is characterized in that: the quantity of this first resistance and this second resistance respectively is one, and in parallel each other.

12. constant current source as claimed in claim 7 produces circuit, it is characterized in that: the quantity of this first resistance is one, and the quantity of this second resistance is two, this first resistance and these second resistance one of them in parallel after, wherein another is connected with these second resistance again.

13. a temperature-compensation circuit, for the certain voltage reference circuit is done temperature-compensating, this temperature-compensation circuit comprises:

One the first transistor, its base stage and collection utmost point ground connection, and its emitter-base bandgap grading is coupled to this and decides reference circuits and accept a reference current;

One transistor seconds, its base stage and collection utmost point ground connection, and its emitter-base bandgap grading is coupled to this and decides reference circuits, with accept one with the proportional electric current of this reference current;

One resistor, be serially connected with this emitter-base bandgap grading of deciding reference circuits and this first transistor and this transistor seconds emitter-base bandgap grading one of them;

It is characterized in that:

This resistor comprises:

At least one first resistance; And

At least one second resistance is coupled to this first resistance, and this first resistance and this second resistance one of them have the characteristic of negative temperature coefficient, wherein another has the characteristic of positive temperature coefficient.

14. constant current source as claimed in claim 13 produces circuit, it is characterized in that: the quantity of this first resistance and this second resistance respectively is one, and series connection each other.

15. constant current source as claimed in claim 13 produces circuit, it is characterized in that: the quantity of this first resistance and this second resistance respectively is one, and in parallel each other.

16. constant current source as claimed in claim 13 produces circuit, it is characterized in that: the quantity of this first resistance is one, and the quantity of this second resistance is two, this first resistance and these second resistance one of them in parallel after, wherein another is connected with these second resistance again.

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