CN102411391A - Complementary metal oxide semiconductor (CMOS) segmented high-order temperature compensated sub-threshold reference voltage source - Google Patents

Abstract

The invention discloses a complementary metal oxide semiconductor (CMOS) segmented high-order temperature compensated sub-threshold reference voltage source, which comprises a starting circuit, a reference core circuit, a digital temperature detection circuit and a segmented high-order temperature compensation circuit. Current mode reference voltage is obtained by superimposing complementary to absolute temperature (CTAT) current generated by the offset of gate-source voltage VGS of sub-threshold N-channel metal oxide semiconductor (NMOS) field effect transistors and proportional to absolute temperature (PTAT) compensation current generated by gate-source voltage differences of a sub-threshold P-channel metal oxide semiconductor (PMOS) field effect transistors, and is coupled into final output reference voltage by the segmented high-order temperature compensation circuit, so high-order temperature compensated reference voltage is obtained. The sub-threshold reference voltage source has a relatively lower temperature coefficient and a relatively higher power supply rejection ratio, and the temperature coefficient of 5.2ppm/DEG C is obtained through emulation by using a semiconductor manufacturing international corporation (SMIC) 65nm standard process database.

Description

The subthreshold value reference voltage source that a kind of CMOS segmentation is high-order temperature compensated

Technical field

The present invention relates to reference voltage source, relate in particular to the high-order temperature compensated subthreshold value reference voltage source of a kind of CMOS segmentation, belong to power technique fields.

Background technology

Further complicated along with circuit system structure; To the mimic channel basic module; Like A/D, circuit such as D/A converter, wave filter and phaselocked loop have proposed higher precision and rate request, and this has higher requirement to reference voltage source module wherein with regard to meaning system.In addition, reference voltage source is a Key Circuit unit in the Voltagre regulator, and it also is an indispensable ingredient in the DC/DC converter.The stability of reference voltage source has directly determined the quality of circuit performance.General commonly used reference voltage source is the band gap reference of the employing BJT that proposes first of Widlar in 1971; It is that the difference of utilizing the voltage of the base-emitter of BJT to have two emitter junction voltages of negative temperature coefficient and different emitter junction areas has positive temperature coefficient (PTC); With both weighting summations, obtain the reference voltage of zero-temperature coefficient.But because BJT pipe and CMOS technology is compatible bad, its development is restricted.Calendar year 2001 Filanovsky etc. points out to tap being lower than a certain offset operation; Being offset to fixedly, the gate source voltage of the MOSFET of leakage current and the relation of temperature are accurate exponential relationships; Based on this achievement in research; The base-emitter voltage that can replace BJT with the gate source voltage of MOSFET comes the design basis reference source, realizes the design of pure cmos device fiducial reference source.

It is one of important indicator of benchmark reference source precision and stability that temperature is floated coefficient.For the pure CMOS band gap reference of single order temperature compensation, temperature coefficient can reach 200ppm/ ℃ usually.For the temperature coefficient that further reduces fiducial reference source just must carry out the compensation of high-order temperature curvature, at present relatively the high-order temperature curvature compensation method of CMOS reference source commonly used mainly comprise second order curvature compensation technology, technological based on the curvature compensation of integrated resistor temperature coefficient, based on gate source voltage difference weighting compensation technique, based on the ZTC compensation technique etc.

Summary of the invention

The present invention provides a kind of CMOS segmentation high-order temperature compensated subthreshold value reference voltage source; It is a kind of based on subthreshold value work, and utilizes digital temperature testing circuit and the high-order temperature compensated circuit of segmentation to realize the high-order temperature compensated reference voltage source of High Accuracy Control.Take following technical scheme:

The subthreshold value reference voltage source that a kind of CMOS segmentation is high-order temperature compensated; It is characterized in that: be provided with start-up circuit, benchmark core circuit, digital temperature testing circuit and the high-order temperature compensated circuit of segmentation; Start-up circuit exports the benchmark core circuit to; Utilize the single order temperature compensation to produce reference voltage, use the temperature range of the phase inverter testing circuit work of different switching thresholds then through the digital temperature testing circuit, utilize at last that metal-oxide-semiconductor piles up in the high-order temperature compensated circuit of segmentation; Carry out high-order temperature compensatedly in the different temperatures scope respectively, be coupled in the final output reference voltage;

Start-up circuit comprises four metal-oxide-semiconductor: PM0, PM4, PM5 and NM0; Wherein, The substrate of the source electrode of PM0, PM5 and substrate and PM4 all is connected to VDD, and the grid of PM4 and the grid of PM0 all are connected to ground, and the drain electrode of PM0 is connected to the source electrode of PM4; The grid of the drain electrode of PM4 and the grid of PM5 and NM0 links together, and the source electrode of NM0 and drain electrode and substrate all are connected to ground;

The benchmark core circuit comprises 11 metal-oxide-semiconductor: PM1, PM2, PM3, PM6, PM7, PM8, NM1, NM2, NM3, NM4 and NM5 and four resistance R ₁, R ₂, R ₃And R ₄, wherein, the source electrode of PM7, PM6, PM1, PM2, PM3, PM8 and substrate all are connected to VDD, and the grid of the grid of PM7, the drain electrode of NM4 and PM8 is connected resistance R ₁An end, the drain electrode of PM7 and the grid of PM6 are received resistance R ₁The other end; The grid of PM1, PM2, PM3 and the drain electrode of NM1 all are connected to the drain electrode of PM1; The grid of the drain electrode of PM6, NM3 and the grid of NM1, NM2 links together and is connected with the drain electrode of start-up circuit PM5, and the grid of the drain electrode of PM2, NM3 and NM4 is connected to resistance R ₂An end, resistance R ₂The other end be connected to resistance R ₃And R ₄An end, R ₃The other end be connected to grid and the PM3 of NM5, the drain electrode of PM8, resistance R ₄Source electrode and substrate, NM2, source electrode, drain electrode and the substrate of NM5 of the other end and NM1, NM3, NM4 all link together and ground connection;

The digital temperature testing circuit comprises metal-oxide-semiconductor NM6,14 phase inverter inv1, inv2, inv3, inv4, inv5, inv6, inv7, inv8, inv9, inv10, inv11, inv12, inv13, inv14,2 two input nand gate nand1, nand2, four input nand gate nand3 and two resistance R ₅, R ₆, wherein, resistance R ₅An end be connected to VDD, resistance R ₅The other end connect resistance R ₆An end, resistance R ₆The other end connect the drain electrode of NM6 and link together with the input end of phase inverter inv1, inv5, inv8 and inv11; The source electrode of NM6 and substrate are connected to ground; The output terminal of inv1 is connected to the input end of inv2; The output terminal of inv2 is connected to the input end of inv3, and the output terminal of inv3 is connected to the input end of inv4, and the output terminal of inv4 is connected to the input end of Sheffer stroke gate nand1 and the input end of Sheffer stroke gate nand3; The output terminal of inv5 is connected to the input end of inv6, and the output terminal of inv6 is connected to the input end of inv7, and the output terminal of inv7 is connected to input end of reverser nand2 and second input end of Sheffer stroke gate nand3; The output terminal of inv8 is connected to the input end of inv9; The output terminal of inv9 is connected to the input end of inv10; The output terminal of inv10 is connected to another output terminal of Sheffer stroke gate nand1, and the output terminal of Sheffer stroke gate nand1 is connected to the 3rd input end of Sheffer stroke gate nand3; The output terminal of inv11 is connected to the input end of inv12; The output terminal of inv12 is connected to the input end of inv13; The output terminal of inv13 is connected to the input end of inv14, and the output terminal of inv14 is connected to another input end of Sheffer stroke gate nand2, and the output terminal of Sheffer stroke gate nand2 is connected to the 4th input end of Sheffer stroke gate nand3; The input end of digital temperature testing circuit is the grid of NM6, is connected with the grid of benchmark core circuit NM4;

The high-order temperature compensated circuit of segmentation comprises 14 metal-oxide-semiconductor: PM9, PM10, PM11, PM12, PM13, PM14, PM15, PM16, PM17, PM18, PM19, PM20, PM21, PM22; Wherein, The grid of PM1, PM2, PM3 links together in the grid of PM14, PM18, PM20, PM22 and the benchmark core circuit; The grid of PM7, PM8 links together in the grid of PM15, PM16, PM17, PM19, PM21 and the benchmark core circuit; The substrate of the source electrode of PM14, PM15, PM16, PM17, PM18, PM19, PM20, PM21, PM22 and substrate and PM9, PM10, PM11, PM12, PM13 all is connected to VDD; The drain electrode of PM14, PM15 is connected to the source electrode of PM9; The drain electrode of PM16 is connected to the source electrode of PM10, and the drain electrode of PM17, PM18 is connected to the source electrode of PM11, and the drain electrode of PM19, PM20 is connected to the source electrode of PM12; The drain electrode of PM21, PM22 is connected to the source electrode of PM13; The grid of PM9, PM10, PM11, PM12, PM13 is connected respectively to the output terminal of reverser inv7, inv4, Sheffer stroke gate nand3, nand2, nand1 in the digital temperature testing circuit, and the drain electrode of PM3, PM8 links together in the drain electrode of PM9, PM10, PM11, PM12, PM13 and the benchmark core circuit, is reference voltage output end.

Advantage of the present invention and remarkable result:

(1) the present invention utilizes subthreshold value NMOS gate source voltage V _GSThe PTAT offset current stack that CTAT electric current that biasing produces and subthreshold PMOS gate source voltage difference produce obtains the current-mode reference voltage; And with this voltage through the high-order temperature compensated which couple of segmentation among the final output reference voltage, thereby obtain high-order temperature compensated reference voltage;

(2) the present invention uses the temperature range of the phase inverter testing circuit work of different switching thresholds, utilizes metal-oxide-semiconductor to be stacked on the different temperatures scope then and carries out high-order temperature compensatedly respectively, can reach low-down temperature coefficient.

(3) used degenerative method to improve the supply-voltage rejection ratio of integrated circuit in the benchmark core circuit of the present invention.

(4) the present invention adopts the peak point current mirror work in subthreshold value, makes the circuit can be at operation at low power supply voltage, and has high supply-voltage rejection ratio and temperature stability.

Description of drawings

Fig. 1 is an electrical schematic diagram of the present invention;

Fig. 2 is the schematic diagram of digital temperature testing circuit among the present invention;

Fig. 3 is the schematic diagram of the high-order temperature compensated circuit of segmentation among the present invention;

Fig. 4 is the temperature variant simulation result figure of subthreshold value benchmark output voltage that does not use the high-order temperature compensated circuit of segmentation;

Fig. 5 is the simulation result figures of three sections high-order temperature compensated subthreshold value benchmark output voltages with variation of temperature;

Fig. 6 is the simulation result figures of five sections high-order temperature compensated subthreshold value benchmark output voltages with variation of temperature.

Embodiment

Below in conjunction with accompanying drawing invention is elaborated:

Schematic diagram of the present invention is as shown in Figure 1, comprises start-up circuit, benchmark core circuit, digital temperature testing circuit and the high-order temperature compensated circuit of segmentation.

Start-up circuit comprises four metal-oxide-semiconductor: PM0, PM4, PM5 and NM0; Wherein, The substrate of the source electrode of PM0, PM5 and substrate and PM4 all is connected to VDD, and the grid of PM4 and the grid of PM0 all are connected to ground, and the drain electrode of PM0 is connected to the source electrode of PM4; The grid of the drain electrode of PM4 and the grid of PM5 and NM0 links together, and the source electrode of NM0 and drain electrode and substrate all are connected to ground.

The principle of work of start-up circuit is: during the firm electrifying startup of overall circuit, and PM0, PM4, PM5 conducting, the PM5 drain voltage rises, and makes the NM1 conducting, benchmark core circuit operate as normal, the NM0 grid voltage rises gradually, and final PM5 ends, and start-up course is accomplished.

The benchmark core circuit comprises 11 metal-oxide-semiconductor: PM1, PM2, PM3, PM6, PM7, PM8, NM1, NM2, NM3, NM4 and NM5 and four resistance R ₁, R ₂, R ₃And R ₄, wherein, the source electrode of PM7, PM6, PM1, PM2, PM3, PM8 and substrate all are connected to VDD, and the grid of the grid of PM7, the drain electrode of NM4 and PM8 is connected resistance R ₁An end, the drain electrode of PM7 and the grid of PM6 are received resistance R ₁The other end; The grid of PM1, PM2, PM3 and the drain electrode of NM1 all are connected to the drain electrode of PM1; The grid of the drain electrode of PM6, NM3 and the grid of NM1, NM2 links together and is connected with the drain electrode of start-up circuit PM5, and the grid of the drain electrode of PM2, NM3 and NM4 is connected to resistance R ₂An end, resistance R ₂The other end be connected to resistance R ₃And R ₄An end, R ₃The other end be connected to grid and the PM3 of NM5, the drain electrode of PM8, resistance R ₄Source electrode and substrate, NM2, source electrode, drain electrode and the substrate of NM5 of the other end and NM1, NM3, NM4 all link together and ground connection.

The principle of work of benchmark core circuit is: behind the circuit start, PM1, PM2, PM3, NM1 are operated in the saturation region, and PM6, PM7, PM8, NM3, NM4 are operated in sub-threshold region.Sub-threshold region is meant works as V _Gs≤V _ThThe time, but the perform region in the time of enough can making silicon face produce a depletion region is greatly arranged, this moment, the drain-source current of MOSFET was non-vanishing, and drain-source current is called " subthreshold current ".Subthreshold current is the dissufion current that " concentration difference " of source/drain terminal charge carrier of MOSFET produces, and is similar with bipolar transistor, is accurate index variation with gate source voltage.Be operated in the MOSFET of sub-threshold region, its raceway groove is in weak transoid attitude, and most of interface state does not all have " neutralization ", and relevant with it electric capacity can change with the surface potential of raceway groove, shows the capacity effect that discharges and recharges, and the I-V characteristic formula of therefore deriving is very complicated.Here directly quoting the expression formula that the result who finds the solution Poisson equation obtains subthreshold current is:

$I_{\mathrm{ds}}=\mathrm{n\μ}{C}_{\mathrm{ox}}\left(\frac{W}{L}\right){\left(\frac{\mathrm{kT}}{q}\right)}^2\left\{\exp \right[\frac{q}{\mathrm{nkT}}(V_{\mathrm{gs}}-V_{\mathrm{th}})\left]\right\}[1-\exp (-\frac{q{V}_{\mathrm{ds}}}{\mathrm{kT}})]$

C _OxBe unit area gate oxide electric capacity, n is the sub-threshold slope modifying factor, and in the submicrometer processing of standard, the n value is about 1.5.In the circuit of reality, drain-source voltage V _DsMuch larger than kT/q, this moment, subthreshold current can be expressed as:

$I_{\mathrm{ds}}=\mathrm{n\μ}{C}_{\mathrm{ox}}\left(\frac{W}{L}\right){\left(\frac{\mathrm{kT}}{q}\right)}^2\exp \left[\frac{q}{\mathrm{nkT}}(V_{\mathrm{gs}}-V_{\mathrm{th}})\right]$

Subthreshold current is reduced to $I_{\mathrm{Ds}}={\mathrm{KI}}_{\mathrm{ES}}\mathrm{Exp}\left(\frac{V_{\mathrm{Gs}}}{n{V}_T}\right)$

K=W/L wherein, V _T=kT/q is a thermal voltage,

It is a parameter that has nothing to do with technology.

The leakage current that let flow is crossed MOSFET has " zero temp shift " coefficient, then can obtain V by following formula _Gs(T) expression formula is:

$V_{\mathrm{gs}}\left(T\right)=V_{\mathrm{th}}\left(T\right)+n\left(\frac{\mathrm{kT}}{q}\right)\ln \left[\left(\frac{L}{W}\right){\left(\frac{q}{\mathrm{kT}}\right)}^2\left(\frac{I_{\mathrm{ds}}}{\mathrm{n\μ}\left(T\right)C_{\mathrm{ox}}}\right)\right]$

In the formula, μ (T) is and the temperature related technical parameters that it is determined by following formula:

$\mathrm{\μ}\left(T\right)=\mathrm{\μ}\left(T_0\right){\left(\frac{T}{T_0}\right)}^{-m}$

In the formula, μ (T ₀) be that charge carrier is at reference temperature T ₀The time mobility, m is the experience factor relevant with technology, it is worth between 1～2.Get m=2, with V _Gs(T) differentiate gets to temperature:

$\frac{\&PartialD;V_{\mathrm{gs}}}{\&PartialD;T}=\frac{\&PartialD;V_{\mathrm{th}}}{\&PartialD;T}+\frac{\mathrm{nk}}{q}\ln \left[\left(\frac{L}{W}\right){\left(\frac{q}{k}\right)}^2\left(\frac{{\mathrm{<figure-callout\; id="0"\; label="I\; ds\; T"\; filenames="DEST\_PATH\_HSB00000718851200041.png"\; state="\{\{state\}\}">I</figure-callout>}}_{\mathrm{ds}}{T}_{}^{}{}_0^2}{\mathrm{n\&mu;}\left(T_0\right)C_{\mathrm{ox}}}\right)\right]$

Because

And

Much smaller than 1, [(Φ _F+ 0.6)/and T] also less than zero, so the gate source voltage V of subthreshold MOSFET _GsHas negative temperature coefficient.

PM6 in the benchmark heart nuclear power road, PM7, NM3, NM4 and R1 form the peak point current mirror, and V is then arranged _Gs6-V _Gs7=I ₇R ₁, can derive the electric current that flows through PM7 according to the subthreshold current formula and be:

$I_7=\frac{n{V}_T}{R_1}\ln \frac{K_{N4}{K}_{P6}}{K_{N3}{K}_{P7}}$

Wherein, K _N3, K _N4, K _P6, K _P7Be respectively the breadth length ratio of NM3, NM4, PM6, PM7.Can find out I ₇With independent of power voltage, a parameter determining, and I by MOSFET ₇Has positive temperature coefficient.

We know V by the derivation of front _GsHave negative temperature coefficient, then through the mirror image of PM8, PM3, the electric current that flows through PM8 is the PTAT electric current, and the electric current that flows through PM3 is the CTAT electric current, and the electric current that flows through R2 simultaneously also is the CTAT electric current, and the expression formula of this reference voltage is:

$V_{\mathrm{ref}}=\frac{\frac{K_{P3}}{K_{P2}}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="DEST\_PATH\_HSB00000718851200042.png"\; state="\{\{state\}\}">R</figure-callout>}}_3+(\frac{K_{P3}}{K_{P2}}+1)R_4}{R_2+(\frac{K_{P3}}{K_{P2}}+1)R_4}{V}_{\mathrm{gs}4}+[\frac{K_{P8}}{K_{P7}}(R_3+R_4)-\frac{\frac{K_{P3}}{K_{P2}}{R}_3+(\frac{K_{P3}}{K_{P2}}+1)R_4}{R_2+(\frac{K_{P3}}{K_{P2}}+1)R_4}\&times;\frac{K_{P8}}{K_{P7}}{R}_4]I_7$

V wherein _Gs4Be the gate source voltage of NM4, I ₇Be the grid source electric current of PM7, K _P2, K _P3, K _P7, K _P8Be respectively the breadth length ratio of PM2, PM3, PM7, PM8, because V _Gs4Has negative temperature coefficient, I ₇Has positive temperature coefficient (PTC), so then can make the temperature coefficient of reference voltage very little as long as rationally adjust the size of resistance and the breadth length ratio of pipe.

PM2, NM4, NM3, NM1 in the benchmark core circuit forms negative feedback loop simultaneously; Improve the supply-voltage rejection ratio of circuit; In order to improve the frequency stability of circuit; Pull-in frequency building-out capacitor in circuit (metal-oxide-semiconductor NM2 source, leakage and substrate link to each other and grid form electric capacity, use as electric capacity) is very important.But because the temperature compensation to reference voltage is merely first compensation phase in the benchmark core circuit; Temperature coefficient is still very big; In order to reduce the temperature coefficient of circuit, add digital temperature testing circuit and the high-order temperature compensated circuit of segmentation, schematic diagram is respectively Fig. 2 and shown in Figure 3.

The digital temperature testing circuit comprises metal-oxide-semiconductor NM6,14 phase inverter inv1, inv2, inv3, inv4, inv5, inv6, inv7, inv8, inv9, inv10, inv11, inv12, inv13, inv14,2 two input nand gate nand1, nand2, four input nand gate nand3 and two resistance R ₅, R ₆, wherein, resistance R ₅An end be connected to VDD, resistance R ₅The other end connect resistance R ₆An end, resistance R ₆The other end connect the drain electrode of NM6 and link together with the input end of phase inverter inv1, inv5, inv8 and inv11; The source electrode of NM6 and substrate are connected to ground; The output terminal of inv1 is connected to the input end of inv2; The output terminal of inv2 is connected to the input end of inv3, and the output terminal of inv3 is connected to the input end of inv4, and the output terminal of inv4 (L_TC) is connected to the input end of Sheffer stroke gate nand1 and the input end of Sheffer stroke gate nand3; The output terminal of inv5 is connected to the input end of inv6, and the output terminal of inv6 is connected to the input end of inv7, and the output terminal of inv7 (H_TC) is connected to input end of reverser nand2 and second input end of Sheffer stroke gate nand3; The output terminal of inv8 is connected to the input end of inv9; The output terminal of inv9 is connected to the input end of inv10; The output terminal of inv10 is connected to another output terminal of Sheffer stroke gate nand1, and the output terminal of Sheffer stroke gate nand1 (LM_TC) is connected to the 3rd input end of Sheffer stroke gate nand3; The output terminal of inv11 is connected to the input end of inv12; The output terminal of inv12 is connected to the input end of inv13, and the output terminal of inv13 is connected to the input end of inv14, and the output terminal of inv14 is connected to another input end of Sheffer stroke gate nand2; The output terminal of Sheffer stroke gate nand2 (HM_TC) is connected to the 4th input end of Sheffer stroke gate nand3; The output terminal of Sheffer stroke gate nand3 is M_TC, and the input end of digital temperature testing circuit is the grid of NM6, is connected with the grid of benchmark core circuit NM4;

The principle of work of digital temperature testing circuit is: V _Gs4After the voltage process NM6 common source amplification for negative temperature coefficient, the drain voltage of NM6 has positive temperature coefficient (PTC), and voltage amplitude has also amplified.Temperature range is equally divided into five sections, is arranged in order from small to large and is low temperature (L), lower temperature (LM), middle temperature (M), higher temperatures (HM), high temperature (H).Design suitable breadth length ratio and make the switching threshold of phase inverter inv1, inv5, inv8, inv11 different, size is inv1＜inv8＜inv11＜inv5.When temperature is in L; Phase inverter inv1, inv5, inv8, inv11 output all are 1; Then low temp compensating control signal (L_TC) pin is output as 0, and lower temperature compensating control signal (LM_TC), middle temperature compensation are repaid control signal (M_TC), higher temperatures compensating control signal (HM_TC), high temperature compensating control signal (H_TC) pin and be output as 1; When temperature range was in LM, phase inverter inv1 was output as 0, and inv5, inv8, inv11 are output as 1, and then the LM_TC pin is output as 0, and L_TC, M_TC, HM_TC, H_TC pin are output as 1; When temperature range was in M, phase inverter inv1, inv8 were output as 0, and inv5, inv11 are output as 1, and then the M_TC pin is output as 0, and L_TC, LM_TC, HM_TC, H_TC pin are output as 1; When temperature range was in HM, phase inverter inv1, inv8, inv11 were output as 0, and inv5 is output as 1, and then the HM_TC pin is output as 0, and L_TC, LM_TC, M_TC, H_TC pin are output as 1; When temperature range was in H, phase inverter inv1, inv5, inv8, inv11 output all were 0, and then the H_TC pin is output as 0, and L_TC, LM_TC, M_TC, HM_TC pin are output as 1.The pin output voltage is as shown in Figure 2 with variation of temperature.

The high-order temperature compensated circuit of segmentation comprises 14 metal-oxide-semiconductor: PM9, PM10, PM11, PM12, PM13, PM14, PM15, PM16, PM17, PM18, PM19, PM20, PM21, PM22; Wherein, The grid of PM14, PM18, PM20, PM22 is connected to the grid of PM1, PM2, PM3 in the benchmark core circuit; The grid of PM15, PM16, PM17, PM19, PM21 is connected to the grid of PM7, PM8 in the benchmark core circuit; The substrate of the source electrode of PM14, PM15, PM16, PM17, PM18, PM19, PM20, PM21, PM22 and substrate and PM9, PM10, PM11, PM12, PM13 all is connected to VDD; The drain electrode of PM14, PM15 is connected to the source electrode of PM9; The drain electrode of PM16 is connected to the source electrode of PM10, and the drain electrode of PM17, PM18 is connected to the source electrode of PM11, and the drain electrode of PM19, PM20 is connected to the source electrode of PM12; The drain electrode of PM21, PM22 is connected to the source electrode of PM13; The grid of PM9, PM10, PM11, PM12, PM13 is connected respectively to the output terminal (promptly being respectively H_TC, L_TC, M_TC, HM_TC, the output of LM_TC signal) of reverser inv7, inv4, Sheffer stroke gate nand3, nand2, nand1 in the digital temperature testing circuit, and the drain electrode of PM3, PM8 links together in the drain electrode of PM9, PM10, PM11, PM12, PM13 and the benchmark core circuit, is reference voltage output end OUT.

The principle of work of the high-order temperature compensated circuit of segmentation is: do not use the benchmark output voltage of the high-order temperature compensated circuit of segmentation as shown in Figure 4 with the simulation result of variation of temperature.In temperature range was L, pin L_TC was output as 0, and PM10 manages conducting and since the PM16 mirror image electric current of positive temperature coefficient (PTC), so the source-drain current of having injected PM16 for the benchmark output voltage carries out temperature compensation.In temperature range is LM; Pin LM_TC is output as 0, and PM13 manages conducting and since the PM21 mirror image electric current of positive temperature coefficient (PTC); The PM2 mirror image electric current of negative temperature coefficient, so the source-drain current of having injected PM21, PM22 for the benchmark output voltage carries out temperature compensation.In temperature range was M, pin M_TC was output as 0, and PM11 manages conducting and since the PM17 mirror image electric current of positive temperature coefficient (PTC), the PM18 mirror image electric current of negative temperature coefficient, so the source-drain current of having injected PM17, PM18 for the benchmark output voltage carries out temperature compensation.In temperature range is HM; Pin HM_TC is output as 0, and PM12 manages conducting and since the PM19 mirror image electric current of positive temperature coefficient (PTC); The PM20 mirror image electric current of negative temperature coefficient, so the source-drain current of having injected PM19, PM20 for the benchmark output voltage carries out temperature compensation.In temperature range was H, pin H_TC was output as 0, and PM9 manages conducting and since the PM15 mirror image electric current of positive temperature coefficient (PTC), the PM14 mirror image electric current of negative temperature coefficient, so the source-drain current of having injected PM14, PM15 for the benchmark output voltage carries out temperature compensation.Do not use the benchmark output voltage of the high-order temperature compensated circuit of segmentation as shown in Figure 4 with the simulation result of variation of temperature;, the benchmark output voltage of high-order temperature compensated circuit that temperature is divided into three sections is as shown in Figure 5 with the simulation result of variation of temperature, and the benchmark output voltage of high-order temperature compensated circuit that temperature is divided into five sections is as shown in Figure 6 with the simulation result of variation of temperature; Can find out from these three figure; Segments to temperature is many more, and high-order temperature compensated effect is good more, and temperature coefficient is low more; We can infer if can be high-order temperature compensated to the segmentation that temperature is carried out many times thus, and the temperature coefficient of benchmark can reach zero.

When circuit had just powered on, start-up circuit made its operate as normal to benchmark core circuit injection current, and the drain electrode of PM5 outputs to the grid of NM1 in the benchmark core circuit in the start-up circuit.The benchmark core circuit utilizes the single order temperature compensation to produce reference voltage, uses the temperature range of digital temperature testing circuit testing then, and the signal of NM3, NM4 outputs to the grid of NM6 in the digital temperature testing circuit in the benchmark core circuit.Utilize the high-order temperature compensated circuit of segmentation to carry out high-order temperature compensated being coupled in the final output reference voltage respectively at last in the different temperatures scope.

Claims (1)

1. subthreshold value reference voltage source that the CMOS segmentation is high-order temperature compensated; It is characterized in that: be provided with start-up circuit, benchmark core circuit, digital temperature testing circuit and the high-order temperature compensated circuit of segmentation; Start-up circuit exports the benchmark core circuit to; Utilize the single order temperature compensation to produce reference voltage, use the temperature range of the phase inverter testing circuit work of different switching thresholds then through the digital temperature testing circuit, utilize at last that metal-oxide-semiconductor piles up in the high-order temperature compensated circuit of segmentation; Carry out high-order temperature compensatedly in the different temperatures scope respectively, be coupled in the final output reference voltage;

Start-up circuit comprises four metal-oxide-semiconductor: PM0, PM4, PM5 and NM0; Wherein, The substrate of the source electrode of PM0, PM5 and substrate and PM4 all is connected to VDD, and the grid of PM4 and the grid of PM0 all are connected to ground, and the drain electrode of PM0 is connected to the source electrode of PM4; The grid of the drain electrode of PM4 and the grid of PM5 and NM0 links together, and the source electrode of NM0 and drain electrode and substrate all are connected to ground;

The benchmark core circuit comprises 11 metal-oxide-semiconductor: PM1, PM2, PM3, PM6, PM7, PM8, NM1, NM2, NM3, NM4 and NM5 and four resistance R ₁, R ₂, R ₂And R ₃, wherein, the source electrode of PM7, PM6, PM1, PM2, PM3, PM8 and substrate all are connected to VDD, and the grid of the grid of PM7, the drain electrode of NM4 and PM8 is connected resistance R ₁An end, the drain electrode of PM7 and the grid of PM6 are received resistance R ₁The other end; The grid of PM1, PM2, PM3 and the drain electrode of NM1 all are connected to the drain electrode of PM1; The grid of the drain electrode of PM6, NM3 and the grid of NM1, NM2 links together and is connected with the drain electrode of start-up circuit PM5, and the grid of the drain electrode of PM2, NM3 and NM4 is connected to resistance R ₂An end, resistance R ₂The other end be connected to resistance R ₃And R ₄An end, R ₃The other end be connected to grid and the PM3 of NM5, the drain electrode of PM8, resistance R ₄Source electrode and substrate, NM2, source electrode, drain electrode and the substrate of NM5 of the other end and NM1, NM3, NM4 all link together and ground connection;

The digital temperature testing circuit comprises metal-oxide-semiconductor NM6,14 phase inverter inv1, inv2, inv3, inv4, inv5, inv6, inv7, inv8, inv9, inv10, inv11, inv12, inv13, inv14,2 two input nand gate nand1, nand2, four input nand gate nand3 and two resistance R ₅, R ₆, wherein, resistance R ₅An end be connected to VDD, resistance R ₅The other end connect resistance R ₆An end, resistance R ₆The other end connect the drain electrode of NM6 and link together with the input end of phase inverter inv1, inv5, inv8 and inv11; The source electrode of NM6 and substrate are connected to ground; The output terminal of inv1 is connected to the input end of inv2; The output terminal of inv2 is connected to the input end of inv3, and the output terminal of inv3 is connected to the input end of inv4, and the output terminal of inv4 is connected to the input end of Sheffer stroke gate nand1 and the input end of Sheffer stroke gate nand3; The output terminal of inv5 is connected to the input end of inv6, and the output terminal of inv6 is connected to the input end of inv7, and the output terminal of inv7 is connected to input end of reverser nand2 and second input end of Sheffer stroke gate nand3; The output terminal of inv8 is connected to the input end of inv9; The output terminal of inv9 is connected to the input end of inv10; The output terminal of inv10 is connected to another output terminal of Sheffer stroke gate nand1, and the output terminal of Sheffer stroke gate nand1 is connected to the 3rd input end of Sheffer stroke gate nand3; The output terminal of inv11 is connected to the input end of inv12; The output terminal of inv12 is connected to the input end of inv13; The output terminal of inv13 is connected to the input end of inv14, and the output terminal of inv14 is connected to another input end of Sheffer stroke gate nand2, and the output terminal of Sheffer stroke gate nand2 is connected to the 4th input end of Sheffer stroke gate nand3; The input end of digital temperature testing circuit is the grid of NM6, is connected with the grid of benchmark core circuit NM4;

The high-order temperature compensated circuit of segmentation comprises 14 metal-oxide-semiconductor: PM9, PM10, PM11, PM12, PM13, PM14, PM15, PM16, PM17, PM18, PM19, PM20, PM21, PM22; Wherein, The grid of PM1, PM2, PM3 links together in the grid of PM14, PM18, PM20, PM22 and the benchmark core circuit; The grid of PM7, PM8 links together in the grid of PM15, PM16, PM17, PM19, PM21 and the benchmark core circuit; The substrate of the source electrode of PM14, PM15, PM16, PM17, PM18, PM19, PM20, PM21, PM22 and substrate and PM9, PM10, PM11, PM12, PM13 all is connected to VDD; The drain electrode of PM14, PM15 is connected to the source electrode of PM9; The drain electrode of PM16 is connected to the source electrode of PM10, and the drain electrode of PM17, PM18 is connected to the source electrode of PM11, and the drain electrode of PM19, PM20 is connected to the source electrode of PM12; The drain electrode of PM21, PM22 is connected to the source electrode of PM13; The grid of PM9, PM10, PM11, PM12, PM13 is connected respectively to the output terminal of reverser inv7, inv4, Sheffer stroke gate nand3, nand2, nand1 in the digital temperature testing circuit, and the drain electrode of PM3, PM8 links together in the drain electrode of PM9, PM10, PM11, PM12, PM13 and the benchmark core circuit, is reference voltage output end.

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