CN103197722A - Low-static-power current-mode band-gap reference voltage circuit - Google Patents

Abstract

A low-static-power current-mode band-gap reference voltage circuit is based on the basis of a traditional band-gap reference voltage circuit which is provided with two PNP audions Q1 and Q2, three PMOS (positive channel metal oxide semiconductor) transistors M1, M2 and M3, an operational amplifier OP and four resistors R1, R2, R3 and R4. The low-static-power current-mode band-gap reference voltage circuit is characterized by subjecting the traditional band-gap reference voltage circuit to improvements which comprise removing R1 and R3 and additionally and respectively arranging two resistors R5 and R6 between the non-inverting input end of the operational amplifier OP and the drain electrode of the PMOS transistor M3 and between the inverting input end of the operational amplifier OP and the drain electrode of the PMOS transistor M3, wherein the resistance value of the R5 is equal to that of R6. Under the conditions of the same power voltage and the same bias currents of the audions Q1 and Q2, the total static power of the low-static-power current-mode band-gap reference voltage circuit is 70% lower than that of the traditional band-gap reference voltage circuit when the output reference voltage is 1 volt.

Description

A kind of current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation

Technical field

The present invention relates to the bandgap voltage reference circuit, especially a kind of current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation belongs to bipolar transistor (BJT) and metal-oxide semiconductor (MOS) (MOS) transistor integrated circuit technical field.

Background technology

There is a kind of traditional bandgap voltage reference circuit as shown in Figure 1 in the prior art, comprises PNP triode Q1 and Q2, PMOS pipe M1, M2 and M3, operational amplifier OP, resistance R ₁, R ₂, R ₃, R ₄The base stage of Q1 and Q2 and grounded collector, the emitter of Q1 passes through resistance R ₂Link to each other with the drain electrode of the in-phase input end of operational amplifier OP and PMOS pipe M1 and be designated as node A, resistance R ₁Be connected across between node A and the ground, the emitter of Q2 links to each other with the drain electrode that inverting input and the PMOS of operational amplifier OP manage M2 and is designated as Node B, resistance R ₃Be connected across between Node B and the ground, the output terminal of operational amplifier OP is connected with the grid of PMOS pipe M1, M2 and M3, and the drain electrode of PMOS pipe M3 is designated as node C and passes through resistance R ₄Ground connection, source electrode and the substrate of PMOS pipe M1, M2 and M3 meet supply voltage VDD, node C output reference voltage V _RefThe principle of work of band-gap reference circuit shown in Figure 1 is as follows:

The PMOS pipe M1 that breadth length ratio is identical, M2 and M3 constitute equal proportion current mirror, i.e. I ₁=I ₂=I ₃The base-emitter voltage of triode Q2 is:

$V_{\mathrm{BE}2}=V_T\ln \left(\frac{I_{Q2}}{I_{S0}}\right)$ (formula 1)

Wherein, V _TBe thermal voltage, be about 26mv, I at normal temperatures _S0For saturation current and its value of triode Q2 is directly proportional with the emitter area of triode.The base-emitter voltage V of triode _BEFor CTAT(and absolute temperature are inversely proportional to) voltage, at normal temperatures, work as V _BEDuring ≈ 750mV,

The base-emitter voltage of triode Q1 is:

$V_{\mathrm{<figure-callout\; id="1"\; label="BE"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">BE</figure-callout>}1}=V_T\ln \left(\frac{I_{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">Q</figure-callout>}1}}{{\mathrm{NI}}_{S0}}\right)$ (formula 2)

Wherein, N is the ratio of triode Q1 and Q2 emitter area, and better for the matching that makes triode Q1 and Q2, the N value gets 8 usually.Computing operational amplifier OP works in degree of depth negative feedback, makes in the same way that the voltage of input end and reverse input end node A and B equates, is to guarantee I _Q1=I _Q2, resistance R ₁With R ₃Must get identical resistance, then

$I_a=I_b=\frac{V_{\mathrm{BE}2}}{R_3}=\frac{V_{\mathrm{BE}2}}{R_1}$ (formula 3)

Because the base-emitter voltage V of triode _BEBe CTAT voltage, flow through resistance R so ₁Electric current I _aBe the CTAT electric current.Resistance R ₂On pressure drop be:

${\mathrm{\&Delta;V}}_{\mathrm{BE}}=V_{\mathrm{BE}2}-{\mathrm{<figure-callout\; id="1"\; label="V\; BE"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{BE}}=V_T\ln \left(\frac{I_{Q2}}{I_{S0}}\right)-V_T\ln \left(\frac{I_{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">Q</figure-callout>}1}}{{\mathrm{NI}}_{S0}}\right)=V_T\ln N=I_{Q1}{R}_2$ (formula 4)

V again _T=kT/q, k are Boltzmann constants, and q is the electric charge of an electron institute band, V _TTemperature coefficient be:

(formula 5)

Wherein, T ₀=300K is from following formula thermal voltage V as can be known _TPositive temperature coefficient is arranged, so Δ V _BETemperature coefficient also be on the occasion of, and Δ V _BEPass through resistance R ₂Obtaining a PTAT(is directly proportional with absolute temperature) electric current I _Q1, again

$I_3=I_2=I_1=I_{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">Q</figure-callout>}1}+I_a=\frac{{\mathrm{\&Delta;V}}_{\mathrm{BE}}}{R_2}+\frac{V_{\mathrm{BE}2}}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}=\frac{V_T\ln N}{R_2}+\frac{V_{\mathrm{BE}2}}{R_1}$ (formula 6) works as V _BE2≈ 750mV gets N=8, V _TDuring=26mV, order

Can obtain approximate temperature independent electric current I ₁, I ₁Copy to I through the equal proportion current mirror ₃And flow through resistance R ₄The formation temperature coefficient is approximately zero reference voltage:

$V_{\mathrm{ref}}=I_3\&times;R_4=(\frac{V_T\ln N}{R_2}+\frac{V_{\mathrm{BE}2}}{R_1})\&times;R_4$ (formula 7)

Obvious V _RefSize can be by regulating resistance R ₁, R ₂, R ₃And R ₄Value adjust traditional current-mode band-gap reference principle that Here it is arbitrarily.

Along with the fast development of Analogous Integrated Electronic Circuits, it is particularly important that Low-power Technology seems, R1 in traditional current-mode band-gap reference, and R3 two resistance have consumed bigger quiescent dissipation because of direct ground connection.For example in formula 7, work as V _BE2≈ 750mV, N=8, the saturation current I of PNP triode Q2 _S0During ≈ 1fA, tried to achieve by formula 6 Get I by formula 1 _Q1=I _Q2≈ 3.37mA, then

$R_2=\frac{V_T\ln \mathrm{<figure-callout\; id="1"\; label="N\; I\; Q"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">N</figure-callout>}}{I_Q}\&ap;16\mathrm{\&Omega;},{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">R</figure-callout>}}_1=16\&times;8.3=132.8\mathrm{\&Omega;}$ (formula 8) can be asked by formula 6

$I_3=I_2=I_1=\frac{V_T\ln N}{R_2}+\frac{V_{\mathrm{BE}2}}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">R</figure-callout>}}_1}\&ap;9\mathrm{mA}$ (formula 9)

Work as V _RefDuring=1V,

$R_4=\frac{V_{\mathrm{ref}}}{I_3}\&ap;111.1\mathrm{\&Omega;}$ (formula 10)

If supply voltage VDD is 1.5V, total power consumption P of so traditional current-mode reference circuit consumption is about:

P=3 * I ₃* VDD=40.5mW (formula 11)

Obviously, traditional current-mode band-gap reference can not satisfy the requirement of low speed paper tape reader static power disspation, and in order to solve power problems, prior art mostly is that utilization is operated in subthreshold value and linear zone is realized low-power consumption reference source, but the difficult realization on technology of this benchmark.

Summary of the invention

The problem that has big quiescent dissipation at above-mentioned conventional current mould reference voltage; the invention provides a kind of current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation; by with operational amplifier in the traditional structure in the same way the resistance reconfiguration of input end and reverse input end ground connection to reference voltage output end; make that each branch current is fully utilized in the circuit; reduce unnecessary quiescent current, reduced the quiescent dissipation of current-mode reference voltage significantly.

The technical scheme that the present invention solves the problems of the technologies described above is as follows:

A kind of current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation based on traditional bandgap voltage reference circuit, is provided with PNP triode Q1 and Q2, PMOS pipe M1, M2 and M3, operational amplifier OP, resistance R ₁, R ₂, R ₃, R ₄The equal ground connection of the base stage of PNP triode Q1 and Q2 and collector, the emitter of PNP triode Q1 passes through resistance R ₂Drain electrode, resistance R with the in-phase input end of operational amplifier OP and PMOS pipe M1 ₁An end connect resistance R ₁Other end ground connection, drain electrode, the resistance R of the emitter of PNP triode Q2 and the inverting input of operational amplifier OP and PMOS pipe M2 ₃An end connect resistance R ₃Other end ground connection, the output terminal of operational amplifier OP is connected with the grid of PMOS pipe M1, M2 and M3, and resistance R is passed through in the drain electrode of PMOS pipe M3 ₄Ground connection, the source electrode of PMOS pipe M1, M2 and M3 all is connected supply voltage VDD with substrate, the drain electrode output reference voltage V of PMOS pipe M3 _Ref

It is characterized in that: above-mentioned traditional bandgap voltage reference circuit is improved, remove resistance R ₁, R ₃, between the drain electrode of the inverting input of the in-phase input end of operational amplifier OP and operational amplifier OP and PMOS pipe M3, set up resistance R respectively ₅And R ₆Described resistance R ₅=R ₆

Compared with prior art, the invention has the beneficial effects as follows:

High power problems at conventional current mould reference circuit; the present invention puies forward on the basis that does not increase components and parts quiescent dissipation with conventional current mould reference circuit and has reduced approximately 70%, and the size of output reference voltage can be adjusted by the value of regulating resistance R4 on the reference voltage output branch road.

Description of drawings

Fig. 1 is a kind of current-mode bandgap voltage reference circuit of the prior art;

Fig. 2 is the current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation of the present invention.

Embodiment

Below in conjunction with accompanying drawing principle of the present invention and feature are described, the example of lifting only is used for explaining the present invention, is not for limiting scope of the present invention.

Referring to Fig. 2, the current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation of the present invention based on traditional bandgap voltage reference circuit, comprises PNP triode Q1 and Q2, PMOS pipe M1, M2 and M3, operational amplifier OP, resistance R ₁, R ₂, R ₃, R ₄The equal ground connection of the base stage of PNP triode Q1 and Q2 and collector, the emitter of PNP triode Q1 passes through resistance R ₂Drain electrode, resistance R with the in-phase input end of operational amplifier OP and PMOS pipe M1 ₁An end connect resistance R ₁Other end ground connection, drain electrode, the resistance R of the emitter of PNP triode Q2 and the inverting input of operational amplifier OP and PMOS pipe M2 ₃An end connect resistance R ₃Other end ground connection, the output terminal of operational amplifier OP is connected with the grid of PMOS pipe M1, M2 and M3, and resistance R is passed through in the drain electrode of PMOS pipe M3 ₄Ground connection, the source electrode of PMOS pipe M1, M2 and M3 all is connected supply voltage VDD with substrate, the drain electrode output reference voltage V of PMOS pipe M3 _Ref

It is characterized in that: above-mentioned traditional bandgap voltage reference circuit is improved, remove resistance R ₁, R ₃, between the drain electrode of the inverting input of the in-phase input end of operational amplifier OP and operational amplifier OP and PMOS pipe M3, set up resistance R respectively ₅And R ₆Described resistance R ₅=R ₆

Principle of work of the present invention is:

The PMOS pipe M1 that breadth length ratio is identical, M2 and M3 constitute equal proportion current mirror, i.e. I ₁=I ₂=I ₃Computing operational amplifier OP works in degree of depth negative feedback, makes in the same way that the voltage of input end and reverse input end node A and B equates, is to guarantee I _Q1=I _Q2, resistance R ₅With R ₆Must get identical resistance, then

$I_a=I_b=\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_5}=\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_6}$ (formula 12)

Because the base-emitter voltage V of triode _BEBe CTAT voltage, flow through resistance R so ₅Electric current I _aWith flow through resistance R ₆Electric current I _bBe the CTAT electric current.Δ V _BEPass through resistance R ₂Obtain a PTAT electric current I _Q1, again

$I_3=I_2=I_1=I_{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">Q</figure-callout>}1}+I_a=\frac{{\mathrm{\&Delta;V}}_{\mathrm{BE}}}{R_2}+\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_5}=\frac{V_T\ln N}{R_2}+\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_5}$ (formula 13)

Flow through resistance R ₄Electric current I ₄Size be:

$I_4=I_3+I_a+I_b=I_{\mathrm{<figure-callout\; id="1"\; label="Q"\; filenames="HDA00002986691800011.png"\; state="\{\{state\}\}">Q</figure-callout>}1}+{2I}_a+I_b=\frac{V_T\ln N}{R_2}+3\left(\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_5}\right)$ (formula 14)

So the reference voltage of output is:

$V_{\mathrm{ref}}=I_4\&times;R_4=[\frac{V_T\ln N}{R_2}+3\left(\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_5}\right)]\&times;R_4$ (formula 15)

Arrangement back V _RefExpression formula be:

$V_{\mathrm{ref}}=\frac{R_5}{R_5+3R_4}(\frac{V_T\ln N}{R_2}+\frac{{3V}_{\mathrm{BE}2}}{R_5})\&times;R_4$ (formula 16)

Work as V _BE2≈ 750mV gets N=8, V _T=26mV, the time, order Can obtain the reference voltage V of approximate zero temperature coefficient _RefObvious V _RefSize can be by regulating resistance R ₂, R ₄, R ₅And R ₆Value adjust arbitrarily.

Saturation current I as PNP triode Q2 _S0During ≈ 1fA, tried to achieve by formula 15

Get I by formula 1 _Q1=I _Q2≈ 3.37mA, then

$R_2=\frac{V_T\ln N}{I_{Q2}}\&ap;16\mathrm{\&Omega;},R_5=16\&times;24.9=398.4\mathrm{\&Omega;}$ (formula 17)

Suppose required reference voltage V _Ref=1V then can ask R by formula 15 ₄≈ 672.5 Ω, if supply voltage VDD is 1.5V, this moment, current mirror from the electric current that power supply extracts was:

$I_3=I_2=I_1=\frac{V_T\ln N}{R_2}+\frac{V_{\mathrm{BE}2}-V_{\mathrm{ref}}}{R_5}=2.75\mathrm{mA}$ (formula 18)

Total quiescent dissipation P of circuitry consumes is so:

P=3 * I ₃* VDD=12.375mW (formula 19)

As seen from the above equation, all under the identical condition, total quiescent dissipation that output reference voltage consumes when being 1V has reduced about 70% than traditional structure to the New type of current mould reference circuit that the present invention proposes at supply voltage and PNP triode Q1, Q2 bias current.

Claims (2)

1. the current-mode bandgap voltage reference circuit of a low speed paper tape reader static power disspation based on traditional bandgap voltage reference circuit, is provided with PNP triode Q1 and Q2, PMOS pipe M1, M2 and M3, operational amplifier OP, resistance R ₁, R ₂, R ₃, R ₄The equal ground connection of the base stage of PNP triode Q1 and Q2 and collector, the emitter of PNP triode Q1 passes through resistance R ₂Drain electrode, resistance R with the in-phase input end of operational amplifier OP and PMOS pipe M1 ₁An end connect resistance R ₁Other end ground connection, drain electrode, the resistance R of the emitter of PNP triode Q2 and the inverting input of operational amplifier OP and PMOS pipe M2 ₃An end connect resistance R ₃Other end ground connection, the output terminal of operational amplifier OP is connected with the grid of PMOS pipe M1, M2 and M3, and resistance R is passed through in the drain electrode of PMOS pipe M3 ₄Ground connection, the source electrode of PMOS pipe M1, M2 and M3 all is connected supply voltage VDD with substrate, the drain electrode output reference voltage V of PMOS pipe M3 _Ref

It is characterized in that: above-mentioned traditional bandgap voltage reference circuit is improved, remove resistance R ₁, R ₃, between the drain electrode of the inverting input of the in-phase input end of operational amplifier OP and operational amplifier OP and PMOS pipe M3, set up resistance R respectively ₅And R ₆

2. the current-mode bandgap voltage reference circuit of low speed paper tape reader static power disspation according to claim 1 is characterized in that: resistance R ₅=R ₆

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