CN1175331C - Voltage regulator having bidirectional current - Google Patents
Voltage regulator having bidirectional current Download PDFInfo
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- CN1175331C CN1175331C CNB02108176XA CN02108176A CN1175331C CN 1175331 C CN1175331 C CN 1175331C CN B02108176X A CNB02108176X A CN B02108176XA CN 02108176 A CN02108176 A CN 02108176A CN 1175331 C CN1175331 C CN 1175331C
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Abstract
The present invention relates to a voltage regulator which is suitable for an active bus terminator. The voltage regulator comprises a voltage adjusting end, a first operational amplifier, a second operational amplifier, a first transistor and a second transistor, wherein the non-inverse input end of the first operational amplifier is connected with a reference voltage; the inverse input end of the second operational amplifier is connected with the reference voltage; a control grid of the first transistor is connected with the output end of the first operational amplifier, and the source electrode is connected with the voltage adjusting end and is connected with the inverse input end of the first operational amplifier through a feedback circuit; the first transistor and the first operational amplifier form a voltage stabilizing circuit with the capability of outputting current; the control grid of the second transistor is connected with the output end of the second operational amplifier, and the drain electrode is connected with the voltage adjusting end and is connected with the non-inverse input end of the second operational amplifier through the same feedback circuit. Through the voltage regulator, a complementary output power transistor is avoided, and the occurrence of perforative current is avoided.
Description
Technical field
The present invention relates to a kind of voltage regulator (voltage regulator), particularly a kind of terminal organ that provides uses, has the voltage regulator that two-way (bi-directional) electric current is provided and uses the single form output power transistors.
Background technology
Computer system generally can utilize electronic busses (electronic bus) in the different computers element, for example ditch messenger between processor, storer, the I/O element etc.One computer bus also usually in element that computer components is connected between transmit address and control signal.
A kind of common computer peripheral interface, for example (Small ComputerSystems Interface SCSI), can reduce the obstruction (bottleneck) of I/O in the computer system to the personal computer system interface.But, when the data rate of the SCSI bus of flowing through increases, can reduce data complete on bus with SCSI bus transmission line effect in succession; So, because the distance between the increase of data rate, each SCSI branch (stub) increases, the difference on cable design or other factors etc., make terminal (termination) become very important design factor.For instance, owing to having coupling (mismatch) to cause the desire control signals transmitted to be reflected, impedance on each SCSI bus do not cause signal may be repeated to calculate; One of reason of signal reflex is owing to cause impedance to mate when having some resistance differences between transmission line.
Impedance mismatching can utilize the terminal organ (terminator) of bus to solve.Terminal organ can provide bus signals one terminal resistance Rt characteristic impedance (characteristicimpedance) with matched transmission line, also can provide a terminal voltage Vo to help driving circuit to reduce the driving load of bus, as shown in Figure 1.
Generally speaking, terminal organ comprises passive terminal organ (passive terminator) and active terminal organ (active terminator).Be illustrated in figure 2 as a typical passive terminal organ 100, it provides an equivalent termination resistance value R
1* R
2/ (R
1+ R
2) and an equivalent terminal voltage value V
P* R
2/ (R
1+ R
2).One of shortcoming of passive terminal organ 100 is the problem of power consumption; Even because when bus signal line 102 is in standby when high impedance (just), passive terminal organ 100 provides a fixed current path between terminal power line (terminator powerline) 106 and ground connection, cause lasting power consumption.
The active terminal organ, Boulay terminal organ 200 for example shown in Figure 3 can reduce the reflection problems because of impedance mismatching caused on the bus.Generally speaking, present active terminal organ mainly takes to compensate pressure drop, and fixedly voltage stabilizing is to the mode of end device resistance with keeping one, and attempt reduces the problem of reflection.In Boulay terminal organ 200, R provides a terminal resistance, and voltage regulator (voltage regulator) 210 provides a terminal voltage V
0Application for high-speed bus, for example reconfigure the symmetrical driver SSTL_2 bus (Stub SeriesTerminated Logic for 2.5 volts) that utilizes among DDR (Dynamic device reconfiguration) the dynamic RAM DRAM (DynamicRandom Access Memory) at dynamic apparatus, for voltage regulator 210, must possess from a terminal voltage and flow out (sourcing) and the bidirectional current ability that sucks (sinking) electric current.Generally speaking, synchronous rectification Switching Voltage Regulator (synchronous rectified switch moderegulator) possesses the bidirectional current ability: however its needs complicated circuit, at high price and have the shortcoming of switching noise (switching noise).
With reference to Fig. 4 is a United States Patent (USP), NO.5,945,814, the linear voltage regulator that has the bidirectional current ability by the disclosed tradition of Covaro.Be noted that especially Fig. 4 is the element model correction that is indicated among Fig. 5 according to Covaro; Numbering " MMBT3904LTI " is a NPN transistor with the bipolar transistor of " MJD31C ", and " MJD32C " then is the PNP transistor, and the three is all " ON Semiconductor TM " company's manufacturing.That is to say, in the invention of Covaro, be to use the output power transistors of two kinds of forms (NPN and PNP).
With reference to Fig. 5 is a United States Patent (USP), NO.5,608,312, the linear voltage regulator that has the bidirectional current ability by the disclosed another kind of tradition of Wallacc; It need use complementary metal oxide semiconductor element (NMOS and PMOS) for the invention of Wallacc.But, in the viewpoint of considering conveniently to make, getting the raw materials ready with cost, in linear voltage regulator, only use the metal-oxide-semiconductor (MOS), particularly NMOS of the output power element of single form, be that design is gone up desirable.
With reference to Fig. 6 is the output voltage regulator of totem pillar output circuit (totem-pole) form, and it uses NMOS as the output power element.The in addition suitable bias voltage of of this sort voltage regulator is set, and just can flow out and sucks electric current.Yet its shortcoming is that bias voltage needs to adjust according to the starting potential (threshold voltage) of employed specific output power NMOS, so setting range is very narrow; So the narrow bias voltage of scope is set the difficulty that will cause power NMOS to select for use; Moreover when such circuit design changed to some extent in power NMOS characteristic, Chang Wufa avoided running through the generation of electric current (shoot-throughcurrent).
According to above-mentioned, urgently special proposition is a kind of to be applied to initiatively terminal organ, its bi-directional capability that not only possesses outflow and suck electric current, and only uses the output power transistors of single form, and the allowance power crystal property has bigger change.
Summary of the invention
Fundamental purpose of the present invention is to provide a kind of voltage regulator with bidirectional current, is applicable to terminal organ, and it can flow out electric current to bus, also can suck electric current from bus.
Another object of the present invention is to provide a kind of voltage regulator with bidirectional current, be used for terminated bus, it utilizes the output power transistors of single form, and for example whole output power transistors is all NMOS and is used as the output power element.
A further object of the present invention is to provide a kind of voltage regulator with bidirectional current, its linear voltage that is applied to the active terminal organ of bus is regulated, it can avoid running through electric current, and for the starting potential flutter of output power transistors very big adaptive faculty is arranged.
According to above-described purpose, the invention provides a kind of voltage regulator (voltage regulator) and be used for stopping (terminating) bus, it comprises that at least a voltage adjustment end (voltage-regulated terminal) is used to provide one to adjust output voltage to bus termination resistance.The N type MOS (metal-oxide-semiconductor) transistor of one common drain connection is used for flowing out an electric current to bus termination resistance through superpotential adjustment end, wherein the source electrode of the N type MOS (metal-oxide-semiconductor) transistor of common drain connection is connected to voltage adjustment end, the grid of the N type MOS (metal-oxide-semiconductor) transistor of common drain connection is used to receive the control output that first operational amplifier is promoted, and the N type MOS (metal-oxide-semiconductor) transistor of common drain connection has a positive amplification characteristic.The N type MOS (metal-oxide-semiconductor) transistor of one common source connection is used for sucking an electric current through superpotential adjustment end, wherein the drain electrode of the N type MOS (metal-oxide-semiconductor) transistor of common source connection is connected to voltage adjustment end, the grid of the N type MOS (metal-oxide-semiconductor) transistor of common source connection is used to receive the control output that second operational amplifier is promoted, and the N type MOS (metal-oxide-semiconductor) transistor of common source connection has an anti-phase amplification characteristic.First operational amplifier is connected into a positive amplifier, is used for forming a positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of common drain connection.The first operational amplifier utilization comparison, one input reference voltage with by voltage adjustment end through the backfeed loop dividing potential drop and negative feedback voltage and export the control output (inputing to the N type MOS (metal-oxide-semiconductor) transistor of common drain connection) that first operational amplifier promoted.Second operational amplifier is connected into an inverting amplifier, be used for forming a positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of common source connection, the second operational amplifier utilization comparison input reference voltage with by voltage adjustment end through the backfeed loop dividing potential drop and negative feedback voltage and export the control output (inputing to the N type MOS (metal-oxide-semiconductor) transistor of common source connection) that second operational amplifier promoted.
Specifically, the invention provides a kind of voltage regulator (regulator), be used for active bus termination device, it is characterized in that this voltage regulator comprises at least:
One voltage adjustment end (voltage regulated terminal) is used to provide an output to adjust voltage;
One first operational amplifier, a homophase input end of this first operational amplifier is connected with a reference voltage;
One second operational amplifier, an inverting input of this second operational amplifier is connected with this reference voltage;
One the first transistor, one control grid of this first transistor is connected with an output terminal of this first operational amplifier, the one source pole of this first transistor is connected with this voltage adjustment end, and through a backfeed loop (feedback network,) be connected with an inverting input of this first operational amplifier, this first transistor and this first operational amplifier are formed one and are had the mu balanced circuit that flows out current capacity; And
One transistor seconds, one control grid of this transistor seconds is connected with an output terminal of this second operational amplifier, one drain electrode of this transistor seconds is connected with this voltage adjustment end, and be connected with a homophase input end of this second operational amplifier through this backfeed loop, this transistor seconds and this second operational amplifier composition one have the mu balanced circuit of suction current capacity.
Described voltage regulator, comprise that also one first bias voltage source (offset voltage) is connected between this in-phase input end of this reference voltage and this first operational amplifier, be used to import the in-phase input end that one first bias voltage is given this first operational amplifier, the polarity of this first bias voltage makes the in-phase input end of this first operational amplifier receive first magnitude of voltage that this reference voltage deducts this first bias voltage.
Described voltage regulator comprises that also one second bias voltage source is connected between the inverting input of this reference voltage and this second operational amplifier, be used to import the inverting input that one second bias voltage is given this second operational amplifier, the polarity of this second bias voltage makes the inverting input of this second operational amplifier receive one second magnitude of voltage that this reference voltage increases this second bias voltage.
Described backfeed loop also comprises:
One first resistance, an end of this first resistance are connected to this voltage adjustment end, and the other end of this first resistance is connected to the inverting input of this first operational amplifier and the in-phase input end of this second operational amplifier; And
One second resistance, an end of this second resistance are connected to the anti-phase defeated end of this first resistance, this first operational amplifier and the in-phase input end of this second operational amplifier, the other end ground connection of this second resistance.
One drain electrode of described the first transistor is connected with a terminal power supply (terminator power supply).
The one source pole ground connection of described transistor seconds.
This source electrode of described the first transistor is connected with at least one terminal resistance through this voltage adjustment end, makes one first electric current flow out to this terminal resistance from this first transistor.
Described voltage regulator comprises that also this drain electrode of this transistor seconds through this voltage adjustment end, is connected with this terminal resistance, makes this transistor seconds to suck one second electric current from this terminal resistance.
Described the first transistor and this transistor seconds are all N type metal-oxide-semiconductor (MOS) or NPN transistor.
The present invention also provides a kind of voltage regulator (voltage regulator), is used for stopping (terminating) bus, and this voltage regulator comprises at least:
One voltage adjustment end (voltage-regulated terminal) is used to provide one to adjust output voltage to bus termination resistance;
The N type MOS (metal-oxide-semiconductor) transistor of one common drain connection is used for flowing out one first electric current to this bus termination resistance through this voltage adjustment end, wherein the one source pole of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection is connected to this voltage adjustment end, have only when this adjustment output voltage during less than one first critical voltage, the just conducting of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection, one grid of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection is used to receive the control output that one first operational amplifier is released, and the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection has a positive amplification characteristic;
The N type MOS (metal-oxide-semiconductor) transistor of one common source connection is used for sucking one second electric current through this voltage adjustment end, wherein one of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection drain electrode is connected to this voltage adjustment end, have only when this adjustment output voltage during greater than one second critical voltage, the just conducting of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection, one grid of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection is used to receive the control output that one second operational amplifier is promoted, and the N type MOS (metal-oxide-semiconductor) transistor of this common source connection has an anti-phase amplification characteristic;
This first operational amplifier is connected into a positive amplifier, be used for forming one first positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection, this first operational amplifier utilization comparison, one input reference voltage is exported the control output that this first operational amplifier is promoted with a negative feedback voltage of being obtained through a backfeed loop by this voltage adjustment end; And
This second operational amplifier is connected into an inverting amplifier, be used for forming one second positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of this common source connection, utilization relatively this input reference voltage is exported the control output that this second operational amplifier is promoted with this negative feedback voltage of being obtained by this this backfeed loop of voltage adjustment end process.
Described voltage regulator comprises that also one first bias voltage source (offset voltage) is connected between the in-phase input end of this reference voltage and this first operational amplifier, be used to import the in-phase input end that one first bias voltage is given this first operational amplifier, the polarity of this first bias voltage makes the in-phase input end of this first operational amplifier receive the magnitude of voltage that this reference voltage reduces this first bias voltage.
Described voltage regulator comprises that also one second bias voltage source is connected between the inverting input of this reference voltage and this second operational amplifier, be used to import the inverting input that one second bias voltage is given this second operational amplifier, the polarity of this second bias voltage makes the inverting input of this second operational amplifier receive the magnitude of voltage that this reference voltage increases this second bias voltage.
The drain electrode of the N type MOS (metal-oxide-semiconductor) transistor of described common drain connection is connected with a terminal power supply (terminator power supply).
The source ground of the N type MOS (metal-oxide-semiconductor) transistor of described common source connection.
The source electrode of the N type MOS (metal-oxide-semiconductor) transistor of described common drain connection is connected with these bus termination resistance through this voltage adjustment end, makes this first electric current flow out to these bus termination resistance from the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection.
Described voltage regulator also comprises this voltage adjustment end of drain electrode process of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection, be connected with these bus termination resistance, make the N type MOS (metal-oxide-semiconductor) transistor of this common source connection to suck this second electric current from these bus termination resistance.
Described backfeed loop also comprises:
One first resistance, an end of this first resistance are connected to this voltage adjustment end, and the other end of this first resistance is connected to the inverting input of this first operational amplifier and the in-phase input end of this second operational amplifier; And
One second resistance, an end of this second resistance are connected to the inverting input of this first resistance, this first operational amplifier and the in-phase input end of this second operational amplifier, the other end ground connection of this second resistance.
Described voltage regulator comprises that also an electric capacity is connected with this voltage adjustment end, when this adjustment output voltage is between this first critical voltage and this second critical voltage, the neither conducting of N type MOS (metal-oxide-semiconductor) transistor of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection and this common source connection is provided the Low ESR of an AC signal by this electric capacity.
Described first critical voltage value is less than this second critical voltage value.
Description of drawings
Fig. 1 is the circuit diagram of the terminal organ of conventional bus;
Fig. 2 is the circuit diagram of the passive terminal organ of conventional bus;
Fig. 3 is the circuit diagram of the active terminal organ of conventional bus;
Fig. 4 is to use the circuit diagram that has the linear regulator of bidirectional current ability in a tradition of bus;
Fig. 5 is to use another circuit diagram that has the linear regulator of bidirectional current ability in a tradition of bus;
Fig. 6 is the circuit diagram of a traditional totem pillar voltage regulator; And
Fig. 7 is the circuit diagram of linear voltage regulator of the present invention.
Embodiment
When the present invention describes in detail with following embodiment, persons skilled in the art will recognize that and in not breaking away from technical scheme proposed by the invention, can make some corrections and replacement.Use to come disclosed structure or method and the linear voltage regulator element that provides the bus termination device to use not only is provided, also comprise the regulator kind that other are equal, and accompanying drawing also is to be used for being illustrated preferred embodiment, but not the limit scope of the invention in addition.
The invention provides a kind of voltage regulator (voltage regulator), be used for stopping (terminating) bus, it comprises that at least a voltage adjustment end (voltage-regulatedterminal) is used to provide one to adjust output voltage to bus termination resistance.The N type MOS (metal-oxide-semiconductor) transistor of one common drain connection (being an outflow transistor) is used for flowing out an electric current to bus termination resistance through superpotential adjustment end, wherein the source electrode of the N type MOS (metal-oxide-semiconductor) transistor of common drain connection is connected to voltage adjustment end, the grid of the N type MOS (metal-oxide-semiconductor) transistor of common drain connection is used to receive the control output that first operational amplifier is promoted, and the N type MOS (metal-oxide-semiconductor) transistor of common drain connection has a positive amplification characteristic.The N type MOS (metal-oxide-semiconductor) transistor of one common source connection (being a suction transistor) is used for sucking an electric current through superpotential adjustment end from bus termination resistance, wherein the drain electrode of the N type MOS (metal-oxide-semiconductor) transistor of common source connection is connected to voltage adjustment end, the grid of the N type MOS (metal-oxide-semiconductor) transistor of common source connection is used to receive the control output that second operational amplifier is promoted, and the N type MOS (metal-oxide-semiconductor) transistor of common source connection has an anti-phase amplification characteristic.First operational amplifier is connected into a positive amplifier, is used for forming a positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of common drain connection.The first operational amplifier utilization is compared an input reference voltage and is exported the control output (promptly inputing to the N type MOS (metal-oxide-semiconductor) transistor of common drain connection) that first operational amplifier is promoted by the negative feedback voltage of voltage adjustment end (getting through the backfeed loop dividing potential drop).Second operational amplifier is connected into an inverting amplifier, is used for forming another positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of common source connection.The second operational amplifier utilization is compared input reference voltage and is exported the control output (promptly inputing to the N type MOS (metal-oxide-semiconductor) transistor of common source connection) that second operational amplifier is promoted by the negative feedback voltage of voltage adjustment end (getting through the backfeed loop dividing potential drop).Produce input offset voltage at random for fear of two operational amplifiers and cause the conducting simultaneously of two N type MOS (metal-oxide-semiconductor) transistor, cause and run through electric current.So between homophase input end of first operational amplifier and input reference voltage, add one first bias voltage, the polarity of this first bias voltage is to make in-phase input end receive the value that input reference voltage deducts first bias voltage: add one second bias voltage between an inverting input of other first operational amplifier and input reference voltage, the polarity of this second bias voltage is to make inverting input receive the value that input reference voltage increases by second bias voltage, make that so the N type MOS (metal-oxide-semiconductor) transistor of common drain connection is just moved when adjusting output voltage less than one first critical voltage; And when adjusting output voltage greater than one second critical voltage, the N type MOS (metal-oxide-semiconductor) transistor of common source connection is just moved, and wherein second critical voltage is greater than first critical voltage.So can avoid two N type MOS (metal-oxide-semiconductor) transistor to move simultaneously and cause running through electric current.
Fig. 7 shows the embodiment synoptic diagram of the linear regulator according to the present invention.One first output power element (output power device) 14, for example the drain electrode end (drainterminal) of a N type MOS transistor is connected to a terminal power supply V
PThe gate terminal of the first output power element 14 is connected to an output terminal of one first operational amplifier 10; The source terminal of the first output power element 14 is except process terminal resistance 17 (R
t) be connected to some output lines, for example Bus Wire also utilizes a backfeed loop (feedbacknetwork) to be connected to the inverting input (inverting inputterminal) of first operational amplifier 10; Wherein backfeed loop comprises one first resistance, 21 (R
1) and one second resistance, 22 (R
2).First resistance 21 and second resistance 22 can be considered divider resistance (divider resistors).
Similarly, one second output power element 15, for example the source terminal ground connection of a N type MOS transistor; The gate terminal of the second output power element 15 is connected to an output terminal of one second operational amplifier 11; The drain electrode end of the second output power element 15 is except process terminal resistance 17 (R
t) be connected to some output lines, for example Bus Wire also utilizes same backfeed loop (feedback network) to be connected to a homophase input end (noninverting input terminal) of second operational amplifier 11; Wherein backfeed loop also comprises first resistance, 21 (R
1) and second resistance, 22 (R
2).
Be stressed that especially the first output power element 14 is used to flow out an electric current and then is used to suck from terminal resistance 17 for terminal resistance 17, the second output power elements 15 and the electric current that comes, both belong to the semiconductor output power element of same form.That is to say that only use a kind of semiconductor output power element of form in the present invention, for instance, all output power elements only utilize N type MOS transistor (NMOS) or npn bipolar transistor.Selecting the transistorized advantage of single form for use is that manufacturer gets the raw materials ready can be more flexible, moreover manufacturer can select the less semiconductor element of cost for use.
Moreover in present embodiment, the inverting input of first operational amplifier 10 is connected to the in-phase input end of second amplifier 11; And another input end of first operational amplifier 10, promptly in-phase input end connects a reference voltage generator 20 (reference voltage generator) through series connection one first bias voltage source 12 (offset voltage).Another input end of second operational amplifier 11, promptly inverting input also is connected to reference voltage generator 20 through one second bias voltage source 13.First bias voltage source 12 and second bias voltage source 13 can provide bias (offset value) V individually
Off1With V
Off2Give first operational amplifier 10 and second operational amplifier 11, these two biasings can obtain through the input biasing (input offset) of adjusting operational amplifier itself separately usually, and do not need additional power source.In the present embodiment, the in-phase input end of first operational amplifier 10 obtains one than reference voltage V
RefReduce V
Off1Voltage.And the inverting input of second operational amplifier 11 obtains one than reference voltage V
RefIncrease V
Off1Voltage; V
RefIncrease V
Off1All about about number millivolt (mV).The adding of first bias voltage source 12 and second bias voltage source 13 has the function that prevents to run through the electric current generation.
According to general feedback theory analysis as can be known: when the open circuit gain (open-loopgain) of operational amplifier is enough when big (usually greater than 10000), the combination of first operational amplifier 10 and the first output power element 14 (the NMOS outflow transistor of common drain connection) can be exported a voltage stabilizing (V
Ref-V
Off1) * ((R
1+ R
2)/R
2) (i.e. first critical voltage).Output voltage V at output terminal 23
0Less than (V
Ref-V
Off1) * ((R
1+ R
2)/R
2) when (i.e. first critical voltage), the first output power element 14 can be switched on, provide an electric current to output terminal 23 to improve output voltage V
0Another situation is to work as output voltage V
0Greater than (V
Ref-V
Off1) * ((R
1+ R
2)/R
2) time, first operational amplifier 10 is output as 14 not conductings of 0, the first output power element.
On the other hand, the combination of second operational amplifier 11 and the second output power element 15 (NMOS of common source connection sucks transistor) can be exported a voltage stabilizing (V
Ref-V
Off2) * ((R
1+ R
2)/R
2) (i.e. second critical voltage).Make the output voltage V of output terminal 21 when flow into an electric current by terminal resistance 17
0Greater than (V
Ref-V
Off2) * ((R
1+ R
2)/R
2) when (i.e. second critical voltage), the second output power element 15 can be switched on, and sucks an electric current to reduce output voltage V from output terminal 23
0Another situation is output voltage V
0Less than (V
Ref-V
Off2) * ((R
1+ R
2)/R
2) time, second operational amplifier 11 is output as 15 not conductings of 0, the second output power element.Moreover, because (V
Ref-V
Off1) * ((R
1+ R
2)/R
2) must be less than (V
Ref-V
Off2) * ((R
1+ R
2)/R
2), therefore the first output power element 14 and the second output power element 15 not can, conducting simultaneously so can prevent the generation that run through electric current of Vp to ground.
In output voltage V
0Between (V
Ref-V
Off2) * ((R
1+ R
2)/R
2) and (V
Ref-V
Off1) * ((R
1+ R
2)/R
2) between situation the time, the first output power element 14 and the second output power element 15 can conductings; Be responsible for providing the Low ESR of voltage adjustment end one interchange (AC) signal this moment to ground by a capacitor 16.
The above is preferred embodiment of the present invention only, is not to be used to limit claim of the present invention; Other does not break away from the equivalence change of being finished under the disclosed spirit or modifies, and all should comprise in the claim of the present invention.
Claims (11)
1. a voltage regulator (regulator) is used for active bus termination device, it is characterized in that this voltage regulator comprises at least:
One voltage adjustment end (voltage regulated terminal) is used to provide an output to adjust voltage;
One first operational amplifier, a homophase input end of this first operational amplifier is connected with a reference voltage;
One second operational amplifier, an inverting input of this second operational amplifier is connected with this reference voltage;
One the first transistor, one control grid of this first transistor is connected with an output terminal of this first operational amplifier, the one source pole of this first transistor is connected with this voltage adjustment end, and through a backfeed loop (feedback network,) be connected with an inverting input of this first operational amplifier, this first transistor and this first operational amplifier are formed one and are had the mu balanced circuit that flows out current capacity; And
One transistor seconds, one control grid of this transistor seconds is connected with an output terminal of this second operational amplifier, one drain electrode of this transistor seconds is connected with this voltage adjustment end, and be connected with a homophase input end of this second operational amplifier through this backfeed loop, this transistor seconds and this second operational amplifier composition one have the mu balanced circuit of suction current capacity.
2. voltage regulator as claimed in claim 1, it is characterized in that, comprise that also one first bias voltage source (offset voltage) is connected between this in-phase input end of this reference voltage and this first operational amplifier, be used to import the in-phase input end that one first bias voltage is given this first operational amplifier, the polarity of this first bias voltage makes the in-phase input end of this first operational amplifier receive first magnitude of voltage that this reference voltage deducts this first bias voltage.
3. voltage regulator as claimed in claim 2, it is characterized in that, comprise that also one second bias voltage source is connected between the inverting input of this reference voltage and this second operational amplifier, be used to import the inverting input that one second bias voltage is given this second operational amplifier, the polarity of this second bias voltage makes the inverting input of this second operational amplifier receive one second magnitude of voltage that this reference voltage increases this second bias voltage.
4. voltage regulator as claimed in claim 1 is characterized in that described backfeed loop also comprises:
One first resistance, an end of this first resistance are connected to this voltage adjustment end, and the other end of this first resistance is connected to the inverting input of this first operational amplifier and the in-phase input end of this second operational amplifier; And
One second resistance, an end of this second resistance are connected to the anti-phase defeated end of this first resistance, this first operational amplifier and the in-phase input end of this second operational amplifier, the other end ground connection of this second resistance.
5. voltage regulator as claimed in claim 1 is characterized in that a drain electrode of described the first transistor is connected with a terminal power supply (terminator power supply).
6. voltage regulator as claimed in claim 1 is characterized in that the one source pole ground connection of described transistor seconds.
7. voltage regulator as claimed in claim 1, this source electrode that it is characterized in that described the first transistor is connected with at least one terminal resistance through this voltage adjustment end, makes one first electric current flow out to this terminal resistance from this first transistor.
8. voltage regulator as claimed in claim 7 is characterized in that, this drain electrode of this transistor seconds is connected with this terminal resistance through this voltage adjustment end, makes this transistor seconds to suck one second electric current from this terminal resistance.
9. voltage regulator as claimed in claim 1 is characterized in that described the first transistor and this transistor seconds are all N type metal-oxide-semiconductor (MOS) or NPN transistor.
10. a voltage regulator (voltage regulator) is used for stopping (terminating) bus, and this voltage regulator comprises at least:
One voltage adjustment end (voltage-regulated terminal) is used to provide one to adjust output voltage to bus termination resistance;
The N type MOS (metal-oxide-semiconductor) transistor of one common drain connection is used for flowing out one first electric current to this bus termination resistance through this voltage adjustment end, wherein the one source pole of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection is connected to this voltage adjustment end, have only when this adjustment output voltage during less than one first critical voltage, the just conducting of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection, one grid of the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection is used to receive the control output that one first operational amplifier is released, and the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection has a positive amplification characteristic;
The N type MOS (metal-oxide-semiconductor) transistor of one common source connection is used for sucking one second electric current through this voltage adjustment end, wherein one of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection drain electrode is connected to this voltage adjustment end, have only when this adjustment output voltage during greater than one second critical voltage, the just conducting of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection, one grid of the N type MOS (metal-oxide-semiconductor) transistor of this common source connection is used to receive the control output that one second operational amplifier is promoted, and the N type MOS (metal-oxide-semiconductor) transistor of this common source connection has an anti-phase amplification characteristic;
This first operational amplifier is connected into a positive amplifier, be used for forming one first positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of this common drain connection, this first operational amplifier utilization comparison, one input reference voltage is exported the control output that this first operational amplifier is promoted with a negative feedback voltage of being obtained through a backfeed loop by this voltage adjustment end; And
This second operational amplifier is connected into an inverting amplifier, be used for forming one second positive combinational circuit with the N type MOS (metal-oxide-semiconductor) transistor of this common source connection, utilization relatively this input reference voltage is exported the control output that this second operational amplifier is promoted with this negative feedback voltage of being obtained by this this backfeed loop of voltage adjustment end process.
11. voltage regulator as claimed in claim 10 is characterized in that described backfeed loop also comprises:
One first resistance, an end of this first resistance are connected to this voltage adjustment end, and the other end of this first resistance is connected to the inverting input of this first operational amplifier and the in-phase input end of this second operational amplifier; And
One second resistance, an end of this second resistance are connected to the inverting input of this first resistance, this first operational amplifier and the in-phase input end of this second operational amplifier, the other end ground connection of this second resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB02108176XA CN1175331C (en) | 2002-03-28 | 2002-03-28 | Voltage regulator having bidirectional current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB02108176XA CN1175331C (en) | 2002-03-28 | 2002-03-28 | Voltage regulator having bidirectional current |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1448818A CN1448818A (en) | 2003-10-15 |
| CN1175331C true CN1175331C (en) | 2004-11-10 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB02108176XA Expired - Fee Related CN1175331C (en) | 2002-03-28 | 2002-03-28 | Voltage regulator having bidirectional current |
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| Country | Link |
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Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100367142C (en) * | 2003-10-21 | 2008-02-06 | 联发科技股份有限公司 | Low-noise stablized voltage circuit capable of fast stopping working |
| EP2027688B1 (en) * | 2006-04-28 | 2018-06-06 | Micro Motion, Inc. | Bus loop power interface and method |
| KR100812086B1 (en) | 2006-11-30 | 2008-03-07 | 동부일렉트로닉스 주식회사 | Voltage regulator of semiconductor device |
| DE102013219173B4 (en) * | 2013-09-24 | 2016-03-03 | Siemens Aktiengesellschaft | Power supply for electrical focusing of electron beams |
| JP6624979B2 (en) * | 2016-03-15 | 2019-12-25 | エイブリック株式会社 | Voltage regulator |
| CN108227800B (en) * | 2016-12-09 | 2024-06-14 | 兆易创新科技集团股份有限公司 | Voltage stabilizing circuit |
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2002
- 2002-03-28 CN CNB02108176XA patent/CN1175331C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
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| CN1448818A (en) | 2003-10-15 |
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