CN1991655A - Energy gap voltage source - Google Patents

Abstract

An energy gap voltage source consists of three branches by parallel connection, and the first branch consists of PMOS tube (M3) and start resistance (Rs) in series; and the second branch consists of PMOS tube (M2) and a NPN (T2) in series; and the second branch consists of PMOS(M1), resistance (R1) and a NPN (T1) in series, and the NPN (T3) is bridged on the start resistance (Rs) between the first branch and the second branch; The emitter of NPN (T1) and the emitter of NPN (T3) are connected with the resistance (R2) separately; the ratio power source is formed by the PMOS (M1)and PMOS (M2), and the PMOS (M3) is offset; And the collector of the NPN (T1) is short circuit with the base. The invention has simple structure and it just need three offset current when keeping the performance of voltage source, and it reduce the occupied square of chip, and save the power consumption.

Description

A kind of energy gap voltage source

Technical field

The present invention relates to reference voltage source in the mimic channel, especially refer to a kind of energy gap voltage source.

Background technology

Often need to produce the reference voltage source of low temperature drift and high Power Supply Rejection Ratio in mimic channel, energy gap voltage source (bandgap) is very ripe a kind of high-performance reference voltage source wherein.All integrated energy gap voltage source produces reference voltage at present most mimic channel chips.

Therefore, at the circuit structure of energy gap voltage source, formed its many embodiment in the industry.

Yet, realize the energy gap voltage source with littler cost and power consumption, also be one of the applicant's content of endeavouring to study.

Summary of the invention

The object of the present invention is to provide the energy gap voltage source of a kind of simple in structure, low cost and low-power consumption.

A kind of energy gap voltage source that adopts BiCMOS technology to make provided by the present invention, it is characterized in that: it is formed in parallel by three branch roads, and wherein: first branch road is by PMOS pipe M ₃Rs is in series with starting resistance; Second branch road is by PMOS pipe M ₂With NPN pipe T ₂Be in series; The 3rd branch road is by PMOS pipe M ₁, a resistance R ₁With NPN pipe T ₁Be in series successively, again: between first branch road and second branch road and be positioned at and overstate on the starting resistance Rs and meet NPN pipe T ₃NPN manages T ₁Emitter and NPN pipe T ₃Emitter connect a resistance R respectively ₂PMOS manages M ₁With PMOS pipe M ₂The composition current source is by PMOS pipe M ₃Biasing; Collector and the base stage short circuit of NPN pipe T1.

In above-mentioned energy gap voltage source, by PMOS pipe M ₃Bias PMOS pipe M ₁With PMOS pipe M ₂The proportional current I that proportion current source produced that constitutes ₂: I ₁=n: 1.

In above-mentioned energy gap voltage source, NPN manages T ₁With NPN pipe T ₂The launch site area is than being m: 1.

In above-mentioned energy gap voltage source, at starting resistance Rs and NPN pipe T ₃Last adding one switch NMOS pipe M ₄

In above-mentioned energy gap voltage source, NPN manages T ₃The replaceable NMOS of being manages.

The energy gap voltage source that the present invention provides another kind of employing Bipolar technology to make simultaneously, it is formed in parallel by three branch roads, and wherein: first branch road is by PNP pipe T ₆Rs is in series with starting resistance; Second branch road is by PNP pipe T ₅With NPN pipe T ₂Be in series; The 3rd branch road is by PNP pipe T ₄, a resistance R ₁With NPN pipe T ₁Be in series successively, again: between first branch road and second branch road and be positioned at and overstate on the starting resistance Rs and meet NPN pipe T ₃NPN manages T ₁Emitter and NPN pipe T ₃Emitter connect a resistance R respectively ₂PNP manages T ₄With PNP pipe T ₅The composition current source is by PNP pipe T ₆Biasing; Collector and the base stage short circuit of NPN pipe T1.

In above-mentioned energy gap voltage source, by PNP pipe T ₆Biasing PNP pipe T ₄With PNP pipe T ₅The proportional current I that proportion current source produced that constitutes ₂: I ₁=n: 1.

In above-mentioned energy gap voltage source, NPN manages T ₁With NPN pipe T ₂The launch site area is than being m: 1.

In above-mentioned energy gap voltage source, at starting resistance Rs and NPN pipe T ₃Last adding one switch NPN pipe T ₇

In above-mentioned energy gap voltage source, NPN manages T ₃The replaceable NMOS of being manages.

Adopted above-mentioned technical solution, promptly only use three branch roads being made up of six transistors and three resistance just to constitute energy gap (bandgap) voltage reference source of a low temperature drift, high Power Supply Rejection Ratio, this structure is suitable for adopting bipolar technology (Bipolar technology) or ambipolar-CMOS (Complementary Metal Oxide Semiconductor) technology (BiCMOS technology) to make.The present invention is simple in structure, in the performance that guarantees voltage source, only needs three road bias currents, has not only reduced the chip area that occupies, and has saved the power consumption when working.

Description of drawings

Fig. 1 is the circuit diagram that the present invention adopts the energy gap voltage source of BiCMOS technology manufacturing;

Fig. 2 is the circuit diagram that the present invention adopts the energy gap voltage source of Bipolar technology manufacturing;

Fig. 3 is the circuit diagram of the energy gap voltage source of belt switch among Fig. 1;

Fig. 4 is the circuit diagram of the energy gap voltage source of belt switch among Fig. 2.

Embodiment

As shown in Figure 1, the simple energy gap voltage source structure that the present invention adopts BiCMOS technology to make is formed in parallel by three branch roads, wherein:

First branch road is by PMOS pipe M ₃Rs is in series with starting resistance;

Second branch road is by PMOS pipe M ₂With NPN pipe T ₂Be in series;

The 3rd branch road is by PMOS pipe M ₁, a resistance R ₁With NPN pipe T ₁Be in series successively.

NPN manages T ₁Emitter and NPN pipe T ₃Emitter connect a resistance R respectively ₂

NPN manages T ₁Collector and base stage short circuit, last connecting resistance R ₁

Between first branch road and second branch road and be positioned at and overstate on the starting resistance Rs and meet NPN pipe T ₃Perhaps the NMOS pipe after voltage source starts operate as normal, is managed T by this NPN ₃Perhaps this starting resistance of NMOS tube short circuit Rs makes the voltage source operate as normal.

As shown in Figure 2, the simple energy gap voltage source structure that the present invention adopts Bipolar technology to make is formed in parallel by three branch roads, wherein:

First branch road is by PNP pipe T ₆Rs is in series with starting resistance;

Second branch road is by PNP pipe T ₅With NPN pipe T ₂Be in series;

The 3rd branch road is by PNP pipe T ₄, a resistance R ₁With NPN pipe T ₁Be in series successively.

NPN manages T ₁Emitter and NPN pipe T ₃Emitter connect a resistance R respectively ₂

Collector and the base stage short circuit of NPN pipe T1, last connecting resistance R ₁

Between first branch road and second branch road and be positioned at and overstate on the starting resistance Rs and meet NPN pipe T ₃Perhaps the NMOS pipe after voltage source starts operate as normal, is managed T by this NPN ₃Perhaps this starting resistance of NMOS tube short circuit Rs makes the voltage source operate as normal.

In above-mentioned two kinds of energy gap voltage sources, no matter be first kind: PMOS manages M ₁With PMOS pipe M ₂The composition current source is by PMOS pipe M ₃Biasing, the proportional current I of generation ₂: I ₁=n: 1; Still second kind: PNP manages T ₄With PNP pipe T ₅The composition current source is by PNP pipe T ₆Biasing, the proportional current I of generation ₂: I ₁=n: 1; Electric current I ₁And I ₂Flow through the launch site area than being m: 1 T ₁And T ₂Produce Δ V _BE,

${\mathrm{\ΔV}}_{\mathrm{BE}}=\frac{\mathrm{KT}}{q}\ln (m\·n)$

Wherein: K is a Boltzmann constant, and T is a temperature, and q is the quantity of electric charge of electronics, and ln is the symbol of taking the logarithm.

Δ V _BEAt R ₂Last generation electric current I _R2=Δ V _BE/ R ₂=I ₁

So output reference voltage is $V_{\mathrm{ref}}=V_{\mathrm{BE}}+{\mathrm{<figure-callout\; id="1"\; label="I"\; filenames="A20051011201700091.png,A20051011201700101.png"\; state="\{\{state\}\}">I</figure-callout>}}_1\&CenterDot;{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="A20051011201700091.png,A20051011201700101.png"\; state="\{\{state\}\}">R</figure-callout>}}_1=V_{\mathrm{BE}}+\frac{R_1}{R_2}\&CenterDot;\mathrm{\&Delta;}{V}_{\mathrm{BE}}$

Output reference voltage is differentiated to temperature:

$\frac{{\&PartialD;V}_{\mathrm{ref}}}{\&PartialD;T}=\frac{{\&PartialD;V}_{\mathrm{BE}}}{\&PartialD;T}+\frac{R_1}{R_2}\&CenterDot;\frac{{\&PartialD;\mathrm{\&Delta;V}}_{\mathrm{BE}}}{\&PartialD;T}=\frac{{\&PartialD;V}_{\mathrm{BE}}}{\&PartialD;T}+\frac{R_1}{R_2}\&CenterDot;\frac{K}{q}\&CenterDot;\ln (m\&CenterDot;n)$

As long as $\frac{R_1}{R_2}=-\frac{{\&PartialD;V}_{\mathrm{BE}}}{\&PartialD;T}/\left[\frac{K}{q}\ln (m\&CenterDot;n)\right],$ Just make $\frac{\&PartialD;\mathrm{Vref}}{\&PartialD;T}=0,$ Promptly as long as select the proper proportion resistance R ₁, R ₂, just realized the purpose of output reference voltage zero-temperature coefficient.

In the energy gap voltage source structure that the present invention proposes, Rs is a starting resistance, is used to guarantee that the energy gap voltage source can normally start after powering on.After energy gap voltage source operate as normal, triode T ₃Conducting, the short circuit starting resistance guarantees energy gap voltage source operate as normal.Triode T ₃Effect except the short circuit starting resistance, also play biasing triode T ₂The collector voltage effect, guarantee T ₂Collector voltage be approximately equal to T ₁Collector voltage, make T ₁And T ₂Duty identical, improve the performance of energy gap voltage source.

The energy gap voltage source that the present invention also proposes only need be at starting resistance Rs and T on basic structure ₃A switch NMOS pipe of last adding M ₄(referring to Fig. 3), or at starting resistance Rs and T ₃A switch NPN pipe of last adding T ₇(referring to Fig. 4) makes and can close the energy gap voltage source when not working, and power consumption is dropped to zero.

The present invention is realizing the structure that is proposed with 3um BiCMOS technology and 2um Bipolar technology, and experimental result shows, low-power consumption, the high performance index of having reached of the present invention.The test result of the temperature drift coefficient of reference voltage is less than 50ppm/ ℃.

Although the present invention explains with concrete syntax architectural feature, should be understood that the present invention that appended claims limits must be limited to illustrated concrete feature or function.On the contrary, these concrete features and function are just disclosed as the exemplary embodiment of the present invention for required protection.

Claims (10)

1. energy gap voltage source, it is characterized in that: it is formed in parallel by three branch roads, wherein:

First branch road is by PMOS pipe (M ₃) and a starting resistance (Rs) be in series;

Second branch road is by PMOS pipe (M ₂) and NPN pipe (T ₂) be in series;

The 3rd branch road is by PMOS pipe (M ₁), a resistance (R ₁) and NPN pipe (T ₁) be in series successively, again:

Between first branch road and second branch road and be positioned at and overstate on the starting resistance (Rs) and meet NPN pipe (T ₃);

NPN manages (T ₁) emitter and NPN pipe (T ₃) emitter connect a resistance (R respectively ₂);

PMOS manages (M ₁) and PMOS pipe (M ₂) the composition current source, by PMOS pipe (M ₃) biasing; With

The collector and the base stage short circuit of NPN pipe (T1).

2. energy gap voltage source according to claim 1 is characterized in that: described by PMOS pipe (M ₃) bias PMOS pipe (M ₁) and PMOS pipe (M ₂) the proportional current I that proportion current source produced that constitutes ₂: I ₁=n: 1.

3. energy gap voltage source according to claim 2 is characterized in that: described NPN pipe (T ₁) and NPN pipe (T ₂) the launch site area is than for m: 1.

4. energy gap voltage source according to claim 1 is characterized in that: at described starting resistance (Rs) and NPN pipe (T ₃) the last switch NMOS pipe (M that adds ₄).

5. energy gap voltage source according to claim 1 is characterized in that: described NPN pipe (T ₃) replaceablely be the NMOS pipe.

6. energy gap voltage source, it is characterized in that: it is formed in parallel by three branch roads, wherein:

First branch road is by PNP pipe (T ₆) and starting resistance (Rs) be in series;

Second branch road is by PNP pipe (T ₅) and NPN pipe (T ₂) be in series;

The 3rd branch road is by PNP pipe (T ₄), a resistance (R ₁) and NPN pipe (T ₁) be in series successively, again:

Between first branch road and second branch road and be positioned at and overstate on the starting resistance (Rs) and meet NPN pipe (T ₃);

NPN manages (T ₁) emitter and NPN pipe (T ₃) emitter connect a resistance (R respectively ₂);

PNP manages (T ₄) and PNP pipe (T ₅) the composition current source, by PNP pipe (T ₆) biasing;

The collector and the base stage short circuit of NPN pipe (T1).

7. energy gap voltage source according to claim 6 is characterized in that: described by PNP pipe (T ₆) biasing PNP pipe (T ₄) and PNP pipe (T ₅) the proportional current I that proportion current source produced that constitutes ₂: I ₁=n: 1.

8. energy gap voltage source according to claim 7 is characterized in that: described NPN pipe (T ₁) and NPN pipe (T ₂) the launch site area is than for m: 1.

9. energy gap voltage source according to claim 6 is characterized in that: at described starting resistance (Rs) and NPN pipe (T ₃) the last switch NPN pipe (T that adds ₇).

10. energy gap voltage source according to claim 6 is characterized in that: described NPN pipe (T ₃) replaceablely be the NMOS pipe.

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