CN103135647B - Method for adjusting negative temperature coefficients of constant current source and constant current source - Google Patents

Abstract

The invention discloses a method for adjusting negative temperature coefficients of constant current source. The method for adjusting the negative temperature coefficients of the constant current source includes that input voltage V = alpha VBE - Vref is set; the input voltage is added to a resistor to convert to output current I out of the constant current source to obtain a temperature coefficient of the constant current source, wherein VBE is PN junction forward conduction voltage drop of a triode, a negative temperature coefficient of the PN junction voltage drop VBE is shown in the description, alpha is a constant, Vref is a reference voltage, and T is a temperature; and values of the constant alpha and or values of the reference voltage Vref are selected and set to enable the constant current source to obtain k times negative temperature coefficient of PN junction of the triode to achieve adjustment of the negative temperature coefficients of the constant current source. The invention discloses the constant current source utilizing the method for adjusting the negative temperature coefficients of the constant current source as well. The method for adjusting the negative temperature coefficients of the constant current source and the constant current source utilizing the same have the advantage of being capable of conveniently and greatly adjusting to obtain the negative temperature coefficients of the constant current source.

Description

A kind of method and constant current source regulating constant current source negative temperature coefficient

Technical field

The present invention relates to constant current source, be specifically related to a kind of method regulating constant current source negative temperature coefficient, the invention still further relates to the constant current source utilizing the method.

Background technology

Desirable constant current source has nothing to do with voltage and temperature, and namely the internal resistance of constant current source is infinitely great, and current value does not vary with temperature.Generally traditional self-excited push-pull type transducer circuit as shown in Figure 1, this self-excited push-pull type transducer circuit also exists the difficult and shortcoming of high temperature short circuit easy burn-out of cold-starting, because the enlargement factor of self-excited push-pull type transducer circuit is less when low temperature, need larger starting current, and the enlargement factor of circuit is comparatively large when high temperature, only need less starting current just can start.If starting current is still comparatively large under high temperature, when output short-circuit, the power consumption of circuit causes circuit to burn out very greatly and easily.As shown in Figure 2, application number self-excited push-pull type transducer employing constant current source disclosed in the Chinese invention patent application of 201110200894.5 replaces the resistance R1 in Fig. 1, after operating voltage raises, unloaded input current, open circuit loss, conversion efficiency all have a significant improvement.Fig. 2-1 is exactly a kind of constant current source mentioned in this patented claim, this constant current source is a kind of constant current source of negative temperature coefficient, the electric current that constant current source provides when low temperature is larger, self-excited push-pull type transducer is easily started, the electric current that constant current source provides when high temperature is less, when making self-excited push-pull type transducer output short-circuit, power consumption is little, is not easy to burn out.Because this constant current source is an imperfect constant current source, there is certain negative temperature coefficient, the existence of this negative temperature coefficient serves certain temperature compensation function to self-excited push-pull type transducer, can improve the problem of cold-starting difficulty and high temperature short circuit easy burn-out to a certain extent simultaneously.

But, the negative temperature coefficient absolute value of the constant current source of the traditional structure as shown in Fig. 2-1 is still large not, if do not consider the temperature coefficient of resistance, the temperature coefficient of this kind of constant current source is the temperature coefficient of a PN junction, be approximately-3000ppm/k, can not meet the temperature compensation requirement of some circuit, if need the negative temperature coefficient of-7000ppm/k just can meet the demands, the temperature coefficient of a PN junction is not accomplished at all.Certainly, also the resistance R80 of self-excited push-pull type transducer in such as Fig. 2 can be changed into a thermistor, thus increase constant current source negative temperature coefficient, the method is if application number is for described in the Chinese invention patent application of 201110272261.5, if connecing positive temperature coefficient (PTC) is the constant current source that the thermistor of 4000ppm/k also can form-7000ppm/k negative temperature coefficient.Because the constant current value of the constant current source as shown in Fig. 2-1 is about:

$I=\frac{V_{\mathrm{BE}80}}{R_{80}}$

So the negative temperature coefficient of this constant current source is:

$\frac{1}{I_{\mathrm{out}}}\×\frac{{\∂I}_{\mathrm{out}}}{\∂T}=\frac{1}{V_{\mathrm{BE}80}}\×\frac{{\∂V}_{\mathrm{BE}80}}{\∂T}-\frac{1}{R_{80}}\×\frac{{\∂R}_{80}}{\∂T}$

Therefore the temperature coefficient of this constant current source is the temperature coefficient that the temperature coefficient of PN junction deducts resistance, if resistance R is the thermistor of positive temperature coefficient (PTC), the absolute value of the negative temperature coefficient of constant current source is by corresponding increase.But thermistor price is more expensive, and can not be integrated, also will increase circuit volume.

Summary of the invention

First object of the present invention is to provide a kind of method regulating constant current source negative temperature coefficient, can facilitate the negative temperature coefficient significantly regulating and obtain constant current source.

Second object of the present invention is to provide a kind of constant current source utilizing said method.

The technical scheme that the present invention realizes above-mentioned first object is:

Regulate a method for constant current source negative temperature coefficient, setting input voltage V=α V _bE-V _ref, this input voltage is added in output current I resistance being converted to constant current source _out, the temperature coefficient obtaining constant current source is: $\frac{1}{I_{\mathrm{out}}}\×\frac{{\∂I}_{\mathrm{out}}}{\∂T}=\frac{1}{V_{\mathrm{BE}}}\×\frac{{\∂V}_{\mathrm{BE}}}{\∂T}\×\frac{1}{1-\frac{V_{\mathrm{ref}}}{\mathrm{\α}{V}_{\mathrm{BE}}}}=k\×\frac{1}{V_{\mathrm{BE}}}\×\frac{\∂V_{\mathrm{BE}}}{\∂T},$ Wherein, $k=\frac{1}{1-\frac{V_{\mathrm{ref}}}{\mathrm{\α}{V}_{\mathrm{BE}}}},$ V _bEfor triode PN junction forward conduction voltage drop, for PN junction pressure drop V _bEnegative temperature coefficient, α is constant, V _reffor reference voltage, T is temperature, by selecting value and/or the reference voltage V of setting constant α _refvalue, thus make constant current source obtain triode PN junction k negative temperature coefficient doubly, realize the negative temperature coefficient regulating constant current source.

On the basis of the above, the present invention can do following improvement:

The trsanscondutance amplifier of operational amplifier and NMOS tube composition is utilized the input voltage of constant current source to be added in output current resistance being converted to constant current source.

The technical scheme that the present invention realizes above-mentioned second object is: a kind of constant current source, comprise power end, the first resistance, the second resistance, the first triode, the second triode, the 3rd triode and the 4th triode, the resistance of described first resistance is much larger than the resistance of the second resistance, described first resistance one end is connected with power end, the first resistance other end respectively with the collector of the first triode, the collector of the second triode and the base stage of the 4th triode are connected, the emitter of described 4th triode respectively with the second transistor base, the base stage of the 3rd triode and the collector of the 3rd triode are connected, the collector of the 3rd triode is connected with power end, the base stage of described first triode is connected with the emitter of the second triode, the grounded emitter of the first triode, one end of described second resistance is connected with the emitter of the 3rd triode, the other end ground connection of the second resistance, the voltage V=V at described second resistance two ends _bE10+ V _bE11-V _bE12≈ 2V _bE-V _bE12=α V _bE-V _ref, utilize the method for described adjustment constant current source negative temperature coefficient, be equivalent to select setting α=2, V _ref=V _bE12, wherein, V _bE10, V _bE11, V _bE12respectively be the PN junction pressure drop of the first triode, the second triode, the 3rd triode, then select the 3rd triode that different emitter area is set as required, obtain different PN junction pressure drop V _bE12, thus regulate the constant current source obtaining tool negative temperature coefficient in need.

Further, constant current source of the present invention also comprises the 5th triode, the other end of described first resistance is connected with the base stage of the 5th triode, the collector of the 5th triode is connected with power end, the emitter of the 5th triode is connected with the base stage of the 4th triode, to form complex pipe, to improve the driving force of the base stage to the 4th triode by the 5th triode and the 4th triode, the resistance of the first resistance can be increased further, reduce bias current.

The present invention utilizes the another kind of embodiment of said method: a kind of constant current source, comprise power end, the first resistance, the second resistance, the first triode, the second triode, the 3rd triode and the 4th triode, the resistance of described first resistance is much larger than the resistance of the second resistance, described first resistance one end is connected with power end, the first resistance other end is connected with the collector of the first triode and the base stage of the 4th triode respectively, the emitter of described 4th triode respectively with the second transistor base, the base stage of the 3rd triode and the collector of the 3rd triode are connected, described power end is connected with the collector of the 3rd triode and the collector of the second triode respectively, the base stage of described first triode is connected with the emitter of the second triode, the grounded emitter of the first triode, one end of described second resistance is connected with the emitter of the 3rd triode, the other end ground connection of the second resistance, the voltage V=V at described second resistance two ends _bE10+ V _bE11-V _bE12≈ 2V _bE-V _bE12=α V _bE-V _ref, utilize the method for described adjustment constant current source negative temperature coefficient, be equivalent to select setting α=2, V _ref=V _bE12, wherein, V _bE10, V _bE11, V _bE12respectively be the PN junction pressure drop of the first triode, the second triode, the 3rd triode, then select the 3rd triode that different emitter area is set as required, obtain different PN junction pressure drop V _bE12, thus regulating the constant current source obtaining tool negative temperature coefficient in need, the base stage of the 4th triode has enough drive currents, good temp characteristic simultaneously.

Further, constant current source of the present invention also comprises the 5th triode, the other end of described first resistance is connected with the base stage of the 5th triode, the collector of the 5th triode is connected with power end, the emitter of the 5th triode is connected with the base stage of the 4th triode, to form complex pipe, to improve the driving force of the base stage to the 4th triode by the 5th triode and the 4th triode, the resistance of the first resistance can be increased further, reduce bias current.

Compared with prior art, the present invention has following beneficial effect:

(1) the present invention regulates setting α or V as required _refthen can realize the convenient adjustment of constant current source negative temperature coefficient, the significantly adjustment of negative temperature coefficient can be realized;

(2) the present invention is by after the area of reduction the 3rd transistor emitter, greatly can improve the absolute value of the negative temperature coefficient of constant current source, thus the temperature compensation requirement met as push-pull converter circuit, after constant current source of the present invention is applied to push-pull converter circuit, effectively can improve the problem of push-pull converter cold-starting difficulty and high temperature short circuit easy burn-out;

(3) constant current source of the present invention changes negative temperature coefficient is that area by arranging the 3rd transistor emitter realizes, exercise price is cheap, and this constant-current source circuit is easy to integrated, volume is little, avoid classic method adopt the price brought of thermistor more expensive, can not integrated, the problem that increases circuit volume.

Accompanying drawing explanation

The existing traditional self-excited push-pull type transducer circuit theory diagrams of Fig. 1;

Fig. 2 provides biased self-excited push-pull type transducer circuit diagram for existing use constant current source;

Fig. 2-1 is traditional negative temperature coefficient constant-current source circuit figure;

Fig. 3 is the circuit theory diagrams that the present invention regulates the method for constant current source negative temperature coefficient;

Fig. 4 is the circuit theory diagrams of the embodiment of the present invention one;

Fig. 5 is the simulation results of the embodiment of the present invention one;

Fig. 6 is the simulation results of the triode of the embodiment of the present invention one constant current source and the process corner of resistance and negative temperature coefficient relation;

Fig. 7 is the circuit theory diagrams of the embodiment of the present invention two;

Fig. 8 is the circuit theory diagrams of the embodiment of the present invention three;

Fig. 9 is the circuit theory diagrams of the embodiment of the present invention four.

Embodiment

Embodiment one

Be illustrated in figure 3 the embodiment one that the present invention regulates the method for constant current source negative temperature coefficient, the present embodiment is proposing a kind of method of application, increase negative temperature coefficient that applicability is stronger.

Logical superpotential computing, setting voltage relational expression is V=α V _bE-V _refinput voltage, then utilize operational amplifier and NMOS tube composition trsanscondutance amplifier, this input voltage, as the input voltage of trsanscondutance amplifier, is added on resistance R0 and is converted to electric current, as the output current of constant current source by this input voltage.Because the electric current producing the circuitry consumes of this voltage relationship in integrated circuits can do very little (microampere rank), relative to general application constant current source little like this electric current negligible.Then by selecting value and/or the reference voltage V of setting constant α _refvalue, the constant current source of various negative temperature coefficient can be obtained.The party's ratio juris is:

As in Fig. 3, the current value of constant current source is about: $I_{\mathrm{out}}=\frac{\mathrm{\α}{V}_{\mathrm{BE}}-V_{\mathrm{ref}}}{R_0},$ The temperature coefficient of negligible resistance, and order $k=\frac{1}{1-\frac{V_{\mathrm{ref}}}{\mathrm{\α}{V}_{\mathrm{BE}}}},$ Then temperature coefficient is: $\frac{1}{I_{\mathrm{out}}}\×\frac{{\∂I}_{\mathrm{out}}}{\∂T}=\frac{1}{V_{\mathrm{BE}}}\×\frac{{\∂V}_{\mathrm{BE}}}{\∂T}\×\frac{1}{1-\frac{V_{\mathrm{ref}}}{\mathrm{\α}{V}_{\mathrm{BE}}}}=k\×\frac{1}{V_{\mathrm{BE}}}\×\frac{\∂V_{\mathrm{BE}}}{\∂T},$

Wherein, V _bEfor triode PN junction forward conduction voltage drop, for PN junction pressure drop V _bEnegative temperature coefficient, α is constant, V _reffor reference voltage, T is temperature, obviously has k>1, so constant current source obtains PN junction k negative temperature coefficient doubly, as long as suitably set V _refand/or the value of α, just can obtain required negative temperature coefficient.

General PN junction pressure drop V _bEnegative temperature coefficient be approximately-3000ppm/k, so the output current I of constant current source will be made _outnegative temperature coefficient become large, just need make k ﹥ 1, from the expression formula of k, as long as make just k ﹥ 1 can be made, therefore α V can be got _bE=2V _bE=2 × 0.7V=1.4V, gets Vref=1V, can obtain k=3.5, so the output current I of constant current source _outnegative temperature coefficient be-3000 × 3.5=-10500ppm/k.Certainly, the value that also can arrange α is as required 3 or more, correspondingly increases triode, forms V _bEsuperposition can realize the value regulating α.

Embodiment two

A kind of constant current source as shown in Figure 4, comprise power end VCC, the first resistance R11, the second resistance R10, the first triode Q10, the second triode Q11, the 3rd triode Q12 and the 4th triode Q13, the resistance of the first resistance R11 is much larger than the resistance of the second resistance R10, the resistance of this first resistance R11 is the bigger the better, ideal value is infinitely great, to make the constant current value of this constant current source closer to the current value by the second resistance R10, first resistance R11 one end is connected with power end VCC, the first resistance R11 other end respectively with the collector of the first triode Q10, the collector of the second triode Q11 and the base stage of the 4th triode Q13 are connected, the emitter of the 4th triode Q13 respectively with the second triode Q11 base stage, the base stage of the 3rd triode Q12 and the collector of the 3rd triode Q12 are connected, the collector of the 3rd triode Q13 is connected with power end VCC, the base stage of the first triode Q10 is connected with the emitter of the second triode Q11, the grounded emitter of the first triode Q10, one end of second resistance R10 is connected with the emitter of the 3rd triode Q12, the other end ground connection of the second resistance R10.

The principle of work of the present embodiment constant current source:

Because the general temperature characterisitic of PN junction pressure drop is: wherein for the band gap voltage of silicon.Work as V _bEwhen=600mV, T=300K, so draw, PN junction pressure drop V _bEtemperature coefficient negative temperature coefficient, and V _bEpressure drop less, the absolute value of its negative temperature coefficient is larger.

In Fig. 4, because the resistance of the first resistance R11 is very large, be equivalent to the internal resistance of constant current source, its bias current is very little and can ignore, so the constant current value of constant current source approximates the current value by the second resistance R10:

$I\≈I_{R10}=\frac{V_{\mathrm{BE}10}+(V_{\mathrm{BE}11}-V_{\mathrm{BE}12})}{R_{10}}...\left(1\right)$

Embodiment one is regulated to the input voltage V=α V in constant current source negative temperature coefficient method _bE-V _ref, when getting α=2, V _ref=V _bE12, R0=R10, then have: V=α V _bE-V _ref=2V _bE-V _bE12≈ V _bE10+ V _bE11-V _bE12, this voltage is added on the second resistance R10 and is converted to electric current, can obtain:

$I_{\mathrm{out}}=\frac{V_{\mathrm{BE}10}+V_{\mathrm{BE}11}-V_{\mathrm{BE}12}}{R_{10}},$ Identical with formula (1).

Therefore, namely the method for the present embodiment two also utilizes the method described in embodiment one, and can be applicable to following examples three, embodiment four and embodiment five equally.

First do not consider the temperature coefficient of each resistance, can be in the hope of the temperature coefficient of constant current source principal current:

$\frac{1}{I}\×\frac{\∂I}{\∂T}=\frac{\frac{{\∂V}_{\mathrm{BE}10}}{\∂T}+(\frac{{\∂V}_{\mathrm{BE}11}}{\∂T}-\frac{{\∂V}_{\mathrm{BE}12}}{\∂T})}{V_{\mathrm{BE}10}+(V_{\mathrm{BE}11}-V_{\mathrm{BE}12})}...\left(2\right)$

V _BE＝V _Tln I/I _s..............................................(3)

In formula (3), I _sfor the inverse current of PN junction, from formula (3), PN junction pressure drop increases along with the electric current flow through and increases, and the electric current flowing through the 3rd triode Q12 is the principal current of constant current source, much larger than the bias current flowing through the first triode Q10 and the second triode Q11, so V _bE11< V _bE12.Again because aforesaid PN junction pressure drop is less, the absolute value of negative temperature coefficient is larger, thus in formula (2) molecule negative temperature coefficient, and the V in formula (2) denominator _bE11-V _bE12also denominator is made to reduce, so the change of molecule and denominator all makes the negative temperature coefficient absolute value of constant current source principal current increase.Be applied to this constant current source in integrated circuit, as long as the emitter area size changing the 3rd triode Q12 just can change the current density of emitter junction, thus change emitter junction pressure drop, the negative temperature coefficient of constant current source can be regulated easily to required value, and its negative temperature coefficient can be adjusted to more than 8000ppm/k.Emitter PN junction area reduces, then current density increases, the pressure drop that 3rd triode Q12PN ties increases along with the reduction of area, equally also can increase current density by increasing current value, satisfying the demand to improve the absolute value of the negative temperature coefficient of constant current source.Certainly, the emitter area size changing the first triode Q10 and/or the second triode Q11 also can increase the absolute value of some negative temperature coefficients, but amplification is very limited, because flow through the first triode Q10, the second triode Q11 electric current very little, thus their current density is very little, change very little to PN junction pressure drop.

As shown in table 1, normal temperature 27 degree, without process deviation (tt process corner) and constant current value is all 3mA time, the situation that the absolute value of negative temperature coefficient changes with the 3rd triode Q12 emitter area.Along with the reduction of the 3rd triode Q12 emitter area size, the absolute value of the negative temperature coefficient of constant current source electric current will increase.Be the temperature coefficient analogous diagram of constant current source electric current shown in Fig. 5, horizontal ordinate is temperature temp (DEG C), and ordinate is electric current (A).During use, select the 3rd triode Q12 that different emitter area is set as required, obtain different PN junction pressure drops, thus obtain the constant current source of tool negative temperature coefficient in need.In integrated circuits, cause the current amplification factor of the triode performance that also can not affect circuit less than normal due to process deviation, make the consistance of product good.As shown in Figure 6, horizontal ordinate is temperature temp (DEG C) to simulation result, and ordinate is electric current (A), negative temperature coefficient has exceeded 7000ppm/k, the process corner that sf, tt, fs represent triode and resistance is marked, sf=bipslow, resfast in Fig. 6; Tt=biptypical, restypical; Fs=bipfast, resslow.

Table 1

Embodiment three

Be illustrated in figure 7 the embodiment two of constant current source of the present invention, the present embodiment two is with the difference of embodiment one: set up the 5th triode Q14.The other end of the first resistance R11 is connected with the base stage of the 5th triode Q14, the collector of the 5th triode Q14 is connected with power end VCC, the emitter of the 5th triode Q14 is connected with the base stage of the 4th triode Q13, to form complex pipe by the 5th triode Q14 and the 4th triode Q13, to improve the driving force to the base stage of the 4th triode Q13, the resistance of the first resistance R11 can be increased further.

Embodiment four

Be illustrated in figure 8 the embodiment three of constant current source of the present invention, the present embodiment three is with the difference of embodiment one: by the collector reconfiguration of the second triode Q11 to power end VCC, the collector of the second triode Q11 is made not draw the electric current of the first resistance R11, and directly can obtain the electric current of power end VCC, thus improve the problem because Q13 ideal base drive current causes temperature characterisitic to be deteriorated not.

Embodiment five

Be illustrated in figure 9 the embodiment four of constant current source of the present invention, the present embodiment four is with the difference of embodiment three: set up the 5th triode Q14.The other end of the first resistance R11 is connected with the base stage of the 5th triode Q14, the collector of the 5th triode Q14 is connected with power end VCC, the emitter of the 5th triode Q14 is connected with the base stage of the 4th triode Q13, to form complex pipe by the 5th triode Q14 and the 4th triode Q13, to improve the driving force to the base stage of the 4th triode, the resistance of the first resistance R11 can be increased further.

Embodiments of the present invention are not limited thereto; according to foregoing of the present invention; utilize ordinary technical knowledge and the customary means of this area; do not departing under the present invention's above-mentioned basic fundamental thought prerequisite; the present invention can also make the amendment of other various ways, replacement or change, all drops within rights protection scope of the present invention.

Claims (6)

1. regulate a method for constant current source negative temperature coefficient, it is characterized in that: setting input voltage V=α V _bE-V _ref, this input voltage is added in output current I resistance being converted to constant current source _out, the temperature coefficient obtaining constant current source is: $\frac{1}{I_{\mathrm{out}}}\&times;\frac{{\&PartialD;I}_{\mathrm{out}}}{\&PartialD;T}=\frac{1}{V_{\mathrm{BE}}}\&times;\frac{{\&PartialD;V}_{\mathrm{BE}}}{\&PartialD;T}\&times;\frac{1}{1-\frac{V_{\mathrm{ref}}}{{\mathrm{\&alpha;V}}_{\mathrm{BE}}}}=k\&times;\frac{1}{V_{\mathrm{BE}}}\&times;\frac{{\&PartialD;V}_{\mathrm{BE}}}{\&PartialD;T},$ Wherein, v _bEfor triode PN junction forward conduction voltage drop, for PN junction pressure drop V _bEnegative temperature coefficient, α is constant, V _reffor reference voltage, T is temperature, by selecting value and/or the reference voltage V of setting constant α _refvalue, thus make constant current source obtain triode PN junction k negative temperature coefficient doubly, realize the negative temperature coefficient regulating constant current source.

2. the method for adjustment constant current source negative temperature coefficient according to claim 1, is characterized in that: utilize the trsanscondutance amplifier of operational amplifier and NMOS tube composition the input voltage of constant current source to be added in output current resistance being converted to constant current source.

3. an application rights requires the constant current source regulating the method for constant current source negative temperature coefficient described in 1, it is characterized in that: comprise power end VCC, the first resistance R11, the second resistance R10, the first triode Q10, the second triode Q11, the 3rd triode Q12 and the 4th triode Q13, the resistance of described first resistance R11 is much larger than the resistance of the second resistance R10, described first resistance R11 one end is connected with power end VCC, the first resistance R11 other end respectively with the collector of the first triode Q10, the collector of the second triode Q11 and the base stage of the 4th triode Q13 are connected, the emitter of described 4th triode Q13 respectively with the second triode Q11 base stage, the base stage of the 3rd triode Q12 and the collector of the 3rd triode Q12 are connected, the collector of the 3rd triode Q13 is connected with power end VCC, the base stage of described first triode Q10 is connected with the emitter of the second triode Q11, the grounded emitter of the first triode Q10, one end of described second resistance R10 is connected with the emitter of the 3rd triode Q12, the other end ground connection of the second resistance R10, the voltage V=V at described second resistance R10 two ends _bE10+ V _bE11-V _bE12≈ 2V _bE-V _bE12=α V _bE-V _ref, α=2, V _ref=V _bE12, wherein, V _bE10, V _bE11, V _bE12respectively be the PN junction pressure drop of the first triode Q10, the second triode Q11, the 3rd triode Q12, then select the 3rd triode Q12 that different emitter area is set as required, obtain different PN junction pressure drop V _bE12, thus regulate the constant current source obtaining tool negative temperature coefficient in need.

4. constant current source according to claim 3, it is characterized in that: described constant current source also comprises the 5th triode Q14, the other end of described first resistance R11 is connected with the base stage of the 5th triode Q14, the collector of the 5th triode Q14 is connected with power end VCC, and the emitter of the 5th triode Q14 is connected with the base stage of the 4th triode Q13.

5. an application rights requires the constant current source regulating the method for constant current source negative temperature coefficient described in 1, it is characterized in that: comprise power end VCC, the first resistance R11, the second resistance R10, the first triode Q10, the second triode Q11, the 3rd triode Q12 and the 4th triode Q13, the resistance of described first resistance R11 is much larger than the resistance of the second resistance R10, described first resistance R11 one end is connected with power end VCC, the first resistance R11 other end is connected with the collector of the first triode Q10 and the base stage of the 4th triode Q13 respectively, the emitter of described 4th triode Q13 respectively with the second triode Q11 base stage, the base stage of the 3rd triode Q12 and the collector of the 3rd triode Q12 are connected, described power end VCC is connected with the collector of the 3rd triode Q13 and the collector of the second triode Q11 respectively, the base stage of described first triode Q10 is connected with the emitter of the second triode Q11, the grounded emitter of the first triode Q10, one end of described second resistance R10 is connected with the emitter of the 3rd triode Q12, the other end ground connection of the second resistance R10, the voltage V=V at described second resistance R10 two ends _bE10+ V _bE11-V _bE12≈ 2V _bE-V _bE12=α V _bE-V _ref, α=2, V _ref=V _bE12, wherein, V _bE10, V _bE11, V _bE12respectively be the PN junction pressure drop of the first triode Q10, the second triode Q11, the 3rd triode Q12, then select the 3rd triode Q12 that different emitter area is set as required, obtain different PN junction pressure drop V _bE12, thus regulate the constant current source obtaining tool negative temperature coefficient in need.

6. constant current source according to claim 5, it is characterized in that: described constant current source also comprises the 5th triode Q14, the other end of described first resistance R11 is connected with the base stage of the 5th triode Q14, the collector of the 5th triode Q14 is connected with power end VCC, and the emitter of the 5th triode Q14 is connected with the base stage of the 4th triode Q13.