CN101930247B - Voltage reference circuit with automatic protection - Google Patents

Abstract

The invention discloses a voltage reference circuit with automatic protection, comprising a band gap voltage reference source circuit, a first biasing circuit, a second biasing circuit, a starting control circuit and a protection control circuit, wherein the voltage output end of the first biasing circuit outputs one-time bipolar transistor base electrode and emitting electrode voltages VBE; the voltage output end of the second biasing circuit outputs double bipolar transistor base electrode and emitting electrode voltages VBE; when voltage reference output by the band gap voltage reference source circuit is lower than the VBE, the starting control circuit controls the voltage reference output by the band gap voltage reference source circuit to rise; and when the voltage reference output by the band gap voltage reference source circuit is higher than 2VBE, the protection control circuit controls the band gap voltage reference source circuit to close. The voltage reference circuit can realize the automatic detection protection when the output of the voltage reference is overhigh or excessive low.

Description

Band is the voltage reference circuit of protection automatically

Technical field

The present invention relates to power circuit, particularly a kind of voltage reference circuit with automatic protection.

Background technology

Voltage reference circuit the most classical in the power management integrated circuit is exactly the bandgap reference voltage source.The principle in bandgap reference voltage source is to utilize the base-emitter voltage V of bipolar transistor (BJT) _BEThe equivalent thermal voltage V of negative temperature coefficient and positive temperature coefficient (PTC) _TCancel out each other and realize the zero temp shift voltage reference.Traditional bandgap reference voltage source Vbg is generally by V _BE+ nV _TTwo parts are formed, V _BEBe the base stage and the emitter voltage of negative temperature coefficient bipolar transistor (BJT), V _TBe the equivalent thermal voltage of positive temperature coefficient (PTC), n is the constant greater than 1, V _BENegative temperature coefficient is about-2mV/ ℃, and V _TThe about 0.086mV/ of positive temperature coefficient (PTC) ℃.Vbg receives the base stage and the emitter voltage V of bipolar transistor _BEThe restriction of about 0.7V adds the equivalent thermal voltage V of n positive temperature coefficient (PTC) constant current source doubly _T, V _TWith the base stage of two BJT pipes in the ratio bipolar transistor circuit of the same type in the positive temperature coefficient (PTC) constant current source and the poor Δ V of emitter voltage _BELinear dependence is so the bandgap reference voltage source of output can also be expressed as V _BE+ n ₁Δ V _BEForm n ₁For greater than 1 constant, the about 1.2V of output voltage reference value, it is a kind of reliable and stable not temperature variant reference voltage.In the side circuit design, often obtain various reference voltage to bandgap reference voltage through resistor network dividing potential drop or multiplication of voltage again.

Shown in Figure 1 is the bandgap voltage reference circuit implementation method that adopts usually under compatible (BCD) technology of bipolar transistor and metal-oxide-semiconductor field effect t.Shown in Figure 1, traditional bandgap voltage reference circuit is made up of ratio bipolar transistor of the same type (BJT) circuit 24, MOS proportional current mirror 23, operational amplifier 1 and output circuit second resistance R 2, the 8th BJT pipe T8 etc.MOS proportional current mirror 23 is made up of P channel metal-oxide FET (PMOS) the first metal-oxide-semiconductor T1, the second metal-oxide-semiconductor T2, the 3rd metal-oxide-semiconductor T3; Wherein the breadth length ratio example of the first metal-oxide-semiconductor T1, the second metal-oxide-semiconductor T2 and the 3rd metal-oxide-semiconductor T3 is 1: 1: k; K is positive constant, and their source electrode (S) all meets positive supply Vdd, and their grid (G) all connects together and connects the output terminal of operational amplifier 1; The drain electrode (D) of the PMOS first metal-oxide-semiconductor T1 connects the anode of the PN junction of the 6th BJT pipe T6; The negativing ending grounding of the PN junction of the 6th BJT pipe T6, the drain electrode of the PMOS second metal-oxide-semiconductor T2 connects first resistance R, 1 one ends, the anode of the PN junction of first resistance R, 1 another termination the 7th BJT pipe T7; The negativing ending grounding of the PN junction of the 7th BJT pipe T7; The drain electrode of PMOS the 3rd metal-oxide-semiconductor T3 is as the voltage reference output terminal and connect an end of second resistance R 2, the anode of the PN junction of another termination the 8th BJT pipe T8 of second resistance R 2, the negativing ending grounding of the PN junction of the 8th BJT pipe T8.Operational amplifier 1 negative input end connects the drain electrode of the first metal-oxide-semiconductor T1 and the anode that the 6th BJT manages the PN junction of T6, an end of the drain electrode of the positive input termination second metal-oxide-semiconductor T2 and first resistance R 1.Ratio BJT pipe circuit 24 of the same type is made up of the 6th BJT pipe T6, the 7th BJT pipe T7 and first resistance R 1; Wherein effective launch site area of the 7th BJT pipe T7 is N times (N＞1) of the 6th BJT pipe T6; The 6th BJT pipe T6, the 7th BJT pipe T7 be base stage, collector short circuit, connects into the PN junction structure.The 8th BJT pipe T8 also connects into the PN junction structure.

Traditional zero-temperature coefficient bandgap voltage reference circuit as shown in Figure 1; Be to utilize operational amplifier 1, MOS matching current mirror 23 to combine ratio bipolar transistor of the same type, the base stage of two BJT pipes of the 6th BJT pipe T6, the 7th BJT pipe T7 and the poor Δ V of emitter voltage _BBOn first resistance R 1, produce steady current with temperature coefficient in direct ratio $\mathrm{Iptat}=\frac{{\mathrm{\&Delta;\; <figure-callout\; id="1"\; label="V\; BE\; R"\; filenames="H2009100574715E00011.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{BE}}}{R}=\frac{V_{\mathrm{BE}6}-V_{\mathrm{BE}7}}{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="H2009100574715E00011.png"\; state="\{\{state\}\}">R</figure-callout>}1},$ V _BE6Be base stage and emitter voltage, the V of the 6th BJT pipe T6 _BE7Be base stage and the emitter voltage of the 7th BJT pipe T7; This positive temperature characterisitic electric current is through the corresponding ratio K of MOS proportional current mirror; On second resistance R 2, produce corresponding positive temperature coefficient (PTC) voltage V2=K*Iptat*R2, and the 8th BJT pipe T8 goes up base stage and emitter voltage difference V _BE8Be negative temperature coefficient voltage, when the two superposes by a certain percentage, just in time can cancel out each other, so can produce the voltage reference Vref=K*Iptat*R2+V that is approximately zero-temperature coefficient _BE8, when technology certain, pipe coupling, this output voltage is just in time near about 1.2 volts of semi-conductive bandgap reference voltage source Vbg.

Traditional bandgap reference voltage source zero temp shift voltage is about 1.2 volts that fix; The main benchmark of making other circuit is used; The tradition bandgap voltage reference circuit only removes to control other circuit as core, even its reference voltage can not turn-off when the problem of generation yet, when bandgap voltage reference circuit work undesired; Voltage reference is exported when too high or too low, can not realize detecting automatically defencive function.

Summary of the invention

The technical matters that the present invention will solve provides a kind of voltage reference circuit with automatic protection, exports when too high or too low when voltage reference, can realize detecting automatically protection.

For solving the problems of the technologies described above, band of the present invention is the voltage reference circuit of protection automatically, comprising: a bandgap reference voltage source circuit, first biasing circuit, second biasing circuit, a start-up control circuit, a protection control circuit; Said one times of bipolar transistor base stage of first biasing circuit voltage output end output and emitter voltage V _BE, said two times of bipolar transistor base stages of second biasing circuit voltage output end output and emitter voltage V _BE, when the voltage reference of bandgap reference voltage source circuit output is lower than V _BEThe time, the voltage reference that said start-up control circuit is controlled said bandgap reference voltage source circuit output raises, and the voltage reference of exporting when the bandgap reference voltage source circuit is higher than 2V _BEThe time, said protection control circuit controls said bandgap reference voltage source circuit and cuts out.

Said first biasing circuit comprises a resistance and a bipolar transistor; Said bipolar transistor base stage and collector short circuit form the PN junction structure; Said resistance one termination positive supply, the anode of the said PN junction of a termination and as the first biasing circuit voltage output end, the negativing ending grounding of said PN junction.

Said second biasing circuit comprises a resistance and two bipolar transistors; Said two bipolar transistors all form two PN junction structures that are connected in series in the same way with base stage with the collector short circuit; Said resistance one termination positive supply; The anode of first PN junction of the said serial connection of another termination and as the second biasing circuit voltage output end, the negative terminal of first PN junction of said serial connection connects the anode of second PN junction, the negativing ending grounding of second PN junction.

Said bandgap reference voltage source comprises ratio bipolar transistor circuit of the same type, MOS proportional current mirror, operational amplifier and output circuit second resistance, the 8th BJT pipe; Said ratio bipolar transistor circuit of the same type comprises PNP the 6th BJT pipe, PNP the 7th BJT pipe and first resistance; The 6th BJT pipe, the 7th BJT manage with base stage and collector short circuit; Form the PN junction structure of emitter and base stage, output circuit PNP the 8th BJT manages the PN junction structure that short circuit too becomes emitter and base stage; Said MOS proportional current mirror comprises PMOS first metal-oxide-semiconductor, PMOS second metal-oxide-semiconductor, PMOS the 3rd metal-oxide-semiconductor, PMOS the 4th metal-oxide-semiconductor; Their source electrode all connects positive supply; Their grid all connects together; The drain electrode of first metal-oxide-semiconductor connects the emitter of PNP the 6th BJT pipe and the negative input end of said operational amplifier, and the drain electrode of PMOS second metal-oxide-semiconductor connects the positive input terminal of operational amplifier and an end of first resistance, the emitter of another termination PNP the 7th BJT pipe of first resistance; Ratio bipolar transistor the 6th BJT pipe of the same type is shorted to ground with the base stage and the collector of the 7th BJT pipe; The drain electrode of PMOS the 3rd metal-oxide-semiconductor is as the voltage reference output terminal and connect an end of output circuit second resistance, the emitter of another termination PNP the 8th BJT pipe of second resistance, and the base stage and the collector of the 8th BJT pipe are shorted to ground; PMOS the 4th metal-oxide-semiconductor grid leak short circuit links to each other with the drain electrode of NMOS the 5th metal-oxide-semiconductor, and the grid of NMOS the 5th metal-oxide-semiconductor connects the output terminal of said operational amplifier;

Said start-up control circuit comprises the 17 comparer and NMOS the 14 metal-oxide-semiconductor; The negative input end of the 17 comparer connects said voltage reference output terminal; The said first biasing circuit voltage output end of the positive input termination of the 17 comparer; The grid of output termination NMOS the 14 metal-oxide-semiconductor of the 17 comparer, the drain electrode of NMOS the 14 metal-oxide-semiconductor connects the drain electrode of NMOS the 5th metal-oxide-semiconductor, the source ground of NMOS the 14 metal-oxide-semiconductor;

Said protection control circuit comprises the 16 comparer and NMOS the 15 metal-oxide-semiconductor; The negative input end of the 16 comparer connects said voltage reference output terminal; The said second biasing circuit voltage output end of the positive input termination of the 16 comparer; The grid of output termination NMOS the 15 metal-oxide-semiconductor of the 16 comparer, the drain electrode of NMOS the 15 metal-oxide-semiconductor connects the source electrode of NMOS the 5th metal-oxide-semiconductor, the source ground of NMOS the 15 metal-oxide-semiconductor.

Said protection control circuit can also be; Comprise the 16 comparer and PMOS the 15 metal-oxide-semiconductor; The said voltage reference output terminal of the positive input termination of the 16 comparer, the negative input end of the 16 comparer connect the said second biasing circuit voltage output end, the grid of output termination PMOS the 15 metal-oxide-semiconductor of the 16 comparer; The source electrode of PMOS the 15 metal-oxide-semiconductor connects the source electrode of NMOS the 5th metal-oxide-semiconductor, the grounded drain of PMOS the 15 metal-oxide-semiconductor.

Band of the present invention is the voltage reference circuit of protection automatically; Under the technology prerequisite of bipolar transistor and metal-oxide-semiconductor field effect t compatibility; On existing conventional bandgap reference voltage structures basis, increase certain bias circuit and control circuit; Utilize standard bandgap voltage-reference voltage to be about 1.2 volts of characteristics that are between 0.7 volt and 1.4 volts, in the certain bias circuit, realize bipolar transistor NPN pipe or one times of base stage of PNP pipe and emitter voltage V _BEBe about 0.7 volt and two times of base stages and emitter voltage V _BEBe about 1.4 volts, realize BJT pipe base stage and emitter voltage V dexterously through circuit structure again _BEThe relatively control of value and the voltage reference Vref of bandgap reference voltage source output, when bandgap reference voltage source output voltage benchmark less than 0.7 volt, startup is quickened in the bandgap reference voltage source; When bandgap reference voltage source output voltage benchmark greater than 0.7 volt during less than 1.4 volts, bandgap reference voltage source operate as normal; When bandgap reference voltage source output voltage benchmark greater than 1.4 volts, bandgap reference voltage is derived from moving closes protection, keeps bandgap reference voltage source output voltage baseline stability and is operated in one times of BJT pipe V _BEValue and two times of BJT pipe V _BEBetween the value, finally reach self-protection function.Being fit to bipolar transistor and metal oxide semiconductor field effect tube compatible technology realizes.

Description of drawings

Fig. 1 is that circuit is realized in traditional bandgap reference voltage source;

Fig. 2 is the band of the present invention voltage reference circuit theory diagram of protection automatically;

Fig. 3 is band of the present invention voltage reference circuit first embodiment of protection automatically;

Fig. 4 is band of the present invention voltage reference circuit second embodiment of protection automatically.

Embodiment

The voltage reference circuit principle that band of the present invention is protected automatically is as shown in Figure 2, comprising: a bandgap reference voltage source circuit, first biasing circuit, second biasing circuit, a start-up control circuit, a protection control circuit; Said one times of bipolar transistor base stage of first biasing circuit voltage output end output and emitter voltage V _BE, said two times of bipolar transistor base stages of second biasing circuit voltage output end output and emitter voltage V _BE, when the voltage reference of bandgap reference voltage source circuit output is lower than V _BEThe time, the voltage reference that said start-up control circuit is controlled said bandgap reference voltage source circuit output raises, and the voltage reference of exporting when the bandgap reference voltage source circuit is higher than 2V _BEThe time, said protection protection control circuit controls said bandgap reference voltage source circuit and cuts out.

Said first biasing circuit comprises a resistance and a bipolar transistor; Said bipolar transistor base stage and collector short circuit form the PN junction structure; Said resistance one termination positive supply, the anode of the said PN of termination knot and as the first biasing circuit voltage output end, the negativing ending grounding of said PN junction.

Said second biasing circuit comprises a resistance and two bipolar transistors; Said two bipolar transistors all form two PN junction structures that are connected in series in the same way with base stage with the collector short circuit; Said resistance one termination positive supply; The anode of first PN junction of the said serial connection of another termination and as the second biasing circuit voltage output end, the negative terminal of first PN junction of said serial connection connects the anode of second PN junction, the negativing ending grounding of second PN junction.

Resistance in said first biasing circuit, second biasing circuit can be the PMOS pipe of a grid leak short circuit; The source electrode of said PMOS pipe connects positive supply, and grid leak connects PN junction, also can be the NMOS pipe of a grid leak short circuit; The grid leak of said NMOS pipe connects positive supply, and source electrode connects PN junction.Said bipolar transistor can also can be managed for PNP for the NPN pipe.

Band of the present invention automatically voltage reference circuit first embodiment of protection is as shown in Figure 3, comprises bandgap reference voltage source, start-up control circuit, protection control circuit, first biasing circuit 21, second biasing circuit 22;

Said bandgap reference voltage source comprises that ratio bipolar transistor of the same type (BJT) circuit, MOS proportional current mirror, operational amplifier 1 and output circuit second resistance R 2, the 8th BJT manage T8; Ratio BJT pipe circuit of the same type comprises PNP the 6th BJT pipe T6, PNP the 7th BJT pipe T7 and first resistance R 1; Wherein effective launch site area of the 7th BJT pipe T7 is N times (N is the constant greater than 1) of the 6th BJT pipe T6; The 6th BJT pipe T6, the 7th BJT pipe T7 are with base stage and collector short circuit; Form the PN junction structure of emitter and base stage, output circuit PNP the 8th BJT manage T8 too short circuit become the PN junction structure of emitter and base stage; MOS proportional current mirror comprises P channel metal-oxide FET (PMOS) the first metal-oxide-semiconductor T1, the second metal-oxide-semiconductor T2, the 3rd metal-oxide-semiconductor T3, the 4th metal-oxide-semiconductor T4; The breadth length ratio example of the first metal-oxide-semiconductor T1, the second metal-oxide-semiconductor T2, the 3rd metal-oxide-semiconductor T3, the 4th metal-oxide-semiconductor T4 is 1: 1: k: 1; K is positive constant; Their source electrode (S) all meets positive supply Vdd; Their grid (G) all connects together; The drain electrode (D) of the PMOS first metal-oxide-semiconductor T1 connects the emitter of PNP the 6th BJT pipe T6 and the negative input end of operational amplifier 1; The drain electrode of the PMOS second metal-oxide-semiconductor T2 connects the positive input terminal of operational amplifier and an end of first resistance R 1, the emitter of another termination PNP the 7th BJT pipe T7 of first resistance R 1, and base stage and the collector of ratio BJT pipe PNP the 6th BJT pipe T6 of the same type and the 7th BJT pipe T7 are shorted to ground; The drain electrode of PMOS the 3rd metal-oxide-semiconductor T3 is as voltage reference Vref output terminal and connect an end of output circuit second resistance R 2; The emitter of another termination PNP the 8th BJT pipe T8 of second resistance R 2, base stage and the collector of the 8th BJT pipe T8 are shorted to ground, and PMOS the 4th metal-oxide-semiconductor T4 grid leak short circuit links to each other with the drain electrode of N channel metal-oxide FET (NMOS) the 5th metal-oxide-semiconductor T5; The source electrode of NMOS the 5th metal-oxide-semiconductor T5 connects the drain electrode of NMOS the 15 metal-oxide-semiconductor T15 downwards, and the grid of NMOS the 5th metal-oxide-semiconductor T5 connects the output terminal of operational amplifier 1.

Said start-up control circuit comprises the 17 comparer 17 and NMOS the 14 metal-oxide-semiconductor T14; The negative input end of the 17 comparer 17 connects voltage reference Vref output terminal; The positive input termination first biasing circuit voltage output end; The grid of output termination NMOS the 14 metal-oxide-semiconductor T14, the drain electrode of NMOS the 14 metal-oxide-semiconductor T14 connects the drain electrode of NMOS the 5th metal-oxide-semiconductor T5, the source ground of NMOS the 14 metal-oxide-semiconductor T14;

Said protection control circuit comprises the 16 comparer 16 and NMOS the 15 metal-oxide-semiconductor T15; The negative input end of the 16 comparer 16 connects voltage reference Vref output terminal; The positive input termination second biasing circuit voltage output end; The grid of output termination NMOS the 15 metal-oxide-semiconductor T15, the drain electrode of NMOS the 15 metal-oxide-semiconductor T15 connects the source electrode of NMOS the 5th metal-oxide-semiconductor T5, the source ground of NMOS the 15 metal-oxide-semiconductor T15;

Said first biasing circuit 21 comprises PMOS the 9th metal-oxide-semiconductor T9 and PNP the tenth BJT pipe T10; The source electrode of PMOS the 9th metal-oxide-semiconductor T9 meets positive supply Vdd; The grid leak short circuit links to each other with the emitter of PNP the tenth BJT pipe T10 and as the first biasing circuit voltage output end, base stage and the collector of the tenth BJT pipe T10 are shorted to ground;

Said second biasing circuit comprises that PMOS the 11 metal-oxide-semiconductor T11 and PNP the 12 BJT pipe T12, PNP the 13 BJT manage T13; The source electrode of PMOS the 11 metal-oxide-semiconductor T11 meets positive supply Vdd; The emitter of the grid leak short circuit of PMOS the 11 metal-oxide-semiconductor T11 and PNP the 12 BJT pipe T12 links to each other and as the second biasing circuit voltage output end; The base stage of the 12 BJT pipe T12 links to each other with the collector short circuit and with the emitter of the 13 BJT pipe T13, and base stage and the collector of the 13 BJT pipe T13 are shorted to ground.

The circuit working Principle of Process is following:

When circuit added positive supply and starts working, first biasing circuit 21 provided the base stage and the emitter voltage value V of single BJT pipe _BE, second biasing circuit 22 provides the base stage and the emitter voltage value V of two BJT pipes _BE, transient voltage benchmark Vref is output as zero, the 16 comparer 16 output high level; NMOS the 15 metal-oxide-semiconductor T15 conducting, the 17 comparer 17 output high level, NMOS the 14 metal-oxide-semiconductor T14 conducting; The grid voltage of PMOS proportional current mirror is reduced rapidly, and the voltage reference Vref of output raises very soon, as the voltage reference Vref of output during greater than 0.7 volt; 17 upsets of the 17 comparer; Output low level, NMOS the 14 metal-oxide-semiconductor T14 turn-offs, and leans on this moment operational amplifier 1 to work with NMOS the 5th metal-oxide-semiconductor T5 and keeps the normal output in bandgap reference voltage source; When the voltage reference Vref of the output in bandgap reference voltage source unusual, when being higher than 1.4 volts, the 16 comparer 16 output low levels; NMOS the 15 metal-oxide-semiconductor T15 turn-offs, and has cut off the current offset in bandgap reference voltage source, thereby makes bandgap reference voltage be derived from the moving protection of closing; As the voltage reference Vref of output during less than 0.7 volt; The 16 comparer 16 output high level, NMOS the 15 metal-oxide-semiconductor T15 conducting, the 17 comparer 17 output high level; NMOS the 14 metal-oxide-semiconductor T14 conducting; The grid voltage of PMOS proportional current mirror is reduced rapidly, and the voltage reference Vref of bandgap reference voltage source output raises again very soon, and the voltage reference Vref that finally keeps the output of bandgap reference voltage source is between 0.7 volt and 1.4 volts.

Bandgap voltage reference circuit second embodiment of the present invention is as shown in Figure 4, and the difference of it and Fig. 3 is at the protection control circuit; Among second embodiment; The protection control circuit comprises the 16 comparer 16 and PMOS the 15 metal-oxide-semiconductor T15; The output terminal of the positive input termination voltage reference Vref of the 16 comparer 16, negative input end connects the second biasing circuit voltage output end, the grid of output termination PMOS the 15 metal-oxide-semiconductor T15; The source electrode of PMOS the 15 metal-oxide-semiconductor T15 connects the source electrode of NMOS the 5th metal-oxide-semiconductor T5, the grounded drain of PMOS the 15 metal-oxide-semiconductor T15.

Band of the present invention is the voltage reference circuit of protection automatically; Under the technology prerequisite of bipolar transistor and metal-oxide-semiconductor field effect t compatibility; On existing conventional bandgap reference voltage structures basis, increase certain bias circuit and control circuit; Utilize standard bandgap voltage-reference voltage to be about 1.2 volts of characteristics that are between 0.7 volt and 1.4 volts, in the certain bias circuit, realize bipolar transistor NPN pipe or one times of base stage of PNP pipe and emitter voltage V _BEBe about 0.7 volt and two times of base stages and emitter voltage V _BEBe about 1.4 volts, realize BJT pipe base stage and emitter voltage V dexterously through circuit structure again _BEThe relatively control of value and the voltage reference Vref of bandgap reference voltage source output, when bandgap reference voltage source output voltage benchmark less than 0.7 volt, startup is quickened in the bandgap reference voltage source; When bandgap reference voltage source output voltage benchmark greater than 0.7 volt during less than 1.4 volts, bandgap reference voltage source operate as normal; When bandgap reference voltage source output voltage benchmark greater than 1.4 volts, bandgap reference voltage is derived from moving closes protection, keeps bandgap reference voltage source output voltage baseline stability and is operated in one times of BJT pipe V _BEValue and two times of BJT pipe V _BEBetween the value, finally reach self-protection function.Being fit to bipolar transistor and metal oxide semiconductor field effect tube compatible technology realizes.

Claims (5)

1. the voltage reference circuit that band is protected automatically is characterized in that, comprising:

One bandgap reference voltage source circuit, first biasing circuit, second biasing circuit, a start-up control circuit, a protection control circuit; Said one times of bipolar transistor base stage of first biasing circuit voltage output end output and emitter voltage V _BE, said two times of bipolar transistor base stages of second biasing circuit voltage output end output and emitter voltage V _BE, when the voltage reference of bandgap reference voltage source circuit output is lower than V _BEThe time, the voltage reference that said start-up control circuit is controlled said bandgap reference voltage source circuit output raises, and the voltage reference of exporting when the bandgap reference voltage source circuit is higher than 2V _BEThe time, said protection control circuit controls said bandgap reference voltage source circuit and cuts out;

Said first biasing circuit comprises a resistance and a bipolar transistor; Said bipolar transistor base stage and collector short circuit form the PN junction structure; Said resistance one termination positive supply, the anode of the said PN junction of a termination and as the first biasing circuit voltage output end, the negativing ending grounding of said PN junction;

Said second biasing circuit comprises a resistance and two bipolar transistors; Said two bipolar transistors all form base stage and collector short circuit two PN junction structures of series aiding connection; Said resistance one termination positive supply; The anode of first PN junction of the said serial connection of another termination and as the second biasing circuit voltage output end, the negative terminal of first PN junction of said serial connection connects the anode of second PN junction, the negativing ending grounding of second PN junction;

The base stage of the single bipolar transistor of first biasing circuit and two bipolar transistors of second biasing circuit and emitter voltage value are V _BE

2. band according to claim 1 is the voltage reference circuit of protection automatically, it is characterized in that, said resistance is the PMOS pipe of a grid leak short circuit, and the source electrode of said PMOS pipe connects positive supply, and grid leak connects PN junction; Or be the NMOS pipe of a grid leak short circuit, the grid leak of said NMOS pipe connects positive supply, and source electrode connects PN junction.

3. band according to claim 1 is the voltage reference circuit of protection automatically, it is characterized in that, the bipolar transistor of said base stage and collector short circuit is NPN pipe or PNP pipe.

4. band according to claim 1 is the voltage reference circuit of protection automatically; It is characterized in that said bandgap reference voltage source comprises ratio bipolar transistor circuit of the same type, MOS proportional current mirror, operational amplifier and output circuit second resistance, the 8th BJT pipe, NMOS the 5th metal-oxide-semiconductor; Said ratio bipolar transistor circuit of the same type comprises PNP the 6th BJT pipe, PNP the 7th BJT pipe and first resistance; The 6th BJT pipe, the 7th BJT manage with base stage and collector short circuit; Form the PN junction structure of emitter and base stage, output circuit PNP the 8th BJT manages the PN junction structure that short circuit too becomes emitter and base stage; Said MOS proportional current mirror comprises PMOS first metal-oxide-semiconductor, PMOS second metal-oxide-semiconductor, PMOS the 3rd metal-oxide-semiconductor, PMOS the 4th metal-oxide-semiconductor; Their source electrode all connects positive supply; Their grid all connects together; The drain electrode of first metal-oxide-semiconductor connects the emitter of PNP the 6th BJT pipe and the negative input end of said operational amplifier, and the drain electrode of PMOS second metal-oxide-semiconductor connects the positive input terminal of operational amplifier and an end of first resistance, the emitter of another termination PNP the 7th BJT pipe of first resistance; Ratio bipolar transistor the 6th BJT pipe of the same type is shorted to ground with the base stage and the collector of the 7th BJT pipe; The drain electrode of PMOS the 3rd metal-oxide-semiconductor is as the voltage reference output terminal and connect an end of output circuit second resistance, the emitter of another termination PNP the 8th BJT pipe of second resistance, and the base stage and the collector of the 8th BJT pipe are shorted to ground; PMOS the 4th metal-oxide-semiconductor grid leak short circuit links to each other with the drain electrode of NMOS the 5th metal-oxide-semiconductor, and the grid of NMOS the 5th metal-oxide-semiconductor connects the output terminal of said operational amplifier;

Said start-up control circuit comprises the 17 comparer and NMOS the 14 metal-oxide-semiconductor; The negative input end of the 17 comparer connects said voltage reference output terminal; The said first biasing circuit voltage output end of the positive input termination of the 17 comparer; The grid of output termination NMOS the 14 metal-oxide-semiconductor of the 17 comparer, the drain electrode of NMOS the 14 metal-oxide-semiconductor connects the drain electrode of NMOS the 5th metal-oxide-semiconductor, the source ground of NMOS the 14 metal-oxide-semiconductor;

Said protection control circuit comprises the 16 comparer and NMOS the 15 metal-oxide-semiconductor; The negative input end of the 16 comparer connects said voltage reference output terminal; The said second biasing circuit voltage output end of the positive input termination of the 16 comparer; The grid of output termination NMOS the 15 metal-oxide-semiconductor of the 16 comparer, the drain electrode of NMOS the 15 metal-oxide-semiconductor connects the source electrode of NMOS the 5th metal-oxide-semiconductor, the source ground of NMOS the 15 metal-oxide-semiconductor.

5. band according to claim 1 is the voltage reference circuit of protection automatically, it is characterized in that,

Said bandgap reference voltage source comprises ratio bipolar transistor circuit of the same type, MOS proportional current mirror, operational amplifier and output circuit second resistance, the 8th BJT pipe, NMOS the 5th metal-oxide-semiconductor; Said ratio bipolar transistor circuit of the same type comprises PNP the 6th BJT pipe, PNP the 7th BJT pipe and first resistance; The 6th BJT pipe, the 7th BJT manage with base stage and collector short circuit; Form the PN junction structure of emitter and base stage, output circuit PNP the 8th BJT manages the PN junction structure that short circuit too becomes emitter and base stage; Said MOS proportional current mirror comprises PMOS first metal-oxide-semiconductor, PMOS second metal-oxide-semiconductor, PMOS the 3rd metal-oxide-semiconductor, PMOS the 4th metal-oxide-semiconductor; Their source electrode all connects positive supply; Their grid all connects together; The drain electrode of first metal-oxide-semiconductor connects the emitter of PNP the 6th BJT pipe and the negative input end of said operational amplifier, and the drain electrode of PMOS second metal-oxide-semiconductor connects the positive input terminal of operational amplifier and an end of first resistance, the emitter of another termination PNP the 7th BJT pipe of first resistance; Ratio bipolar transistor the 6th BJT pipe of the same type is shorted to ground with the base stage and the collector of the 7th BJT pipe; The drain electrode of PMOS the 3rd metal-oxide-semiconductor is as the voltage reference output terminal and connect an end of output circuit second resistance, the emitter of another termination PNP the 8th BJT pipe of second resistance, and the base stage and the collector of the 8th BJT pipe are shorted to ground; PMOS the 4th metal-oxide-semiconductor grid leak short circuit links to each other with the drain electrode of NMOS the 5th metal-oxide-semiconductor, and the grid of NMOS the 5th metal-oxide-semiconductor connects the output terminal of said operational amplifier;

Said start-up control circuit comprises the 17 comparer and NMOS the 14 metal-oxide-semiconductor; The negative input end of the 17 comparer connects said voltage reference output terminal; The said first biasing circuit voltage output end of the positive input termination of the 17 comparer; The grid of output termination NMOS the 14 metal-oxide-semiconductor of the 17 comparer, the drain electrode of NMOS the 14 metal-oxide-semiconductor connects the drain electrode of NMOS the 5th metal-oxide-semiconductor, the source ground of NMOS the 14 metal-oxide-semiconductor;

Said protection control circuit comprises the 16 comparer and PMOS the 15 metal-oxide-semiconductor; The said voltage reference output terminal of the positive input termination of the 16 comparer; The negative input end of the 16 comparer connects the said second biasing circuit voltage output end; The grid of output termination PMOS the 15 metal-oxide-semiconductor of the 16 comparer, the source electrode of PMOS the 15 metal-oxide-semiconductor connects the source electrode of NMOS the 5th metal-oxide-semiconductor, the grounded drain of PMOS the 15 metal-oxide-semiconductor.

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