CN203324874U - Frequency compensating circuit of low dropout voltage regulator - Google Patents
Frequency compensating circuit of low dropout voltage regulator Download PDFInfo
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- CN203324874U CN203324874U CN2013202164045U CN201320216404U CN203324874U CN 203324874 U CN203324874 U CN 203324874U CN 2013202164045 U CN2013202164045 U CN 2013202164045U CN 201320216404 U CN201320216404 U CN 201320216404U CN 203324874 U CN203324874 U CN 203324874U
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Abstract
The utility discloses a frequency compensating circuit of a low dropout voltage regulator. A three-terminal control circuit in the low dropout voltage regulator is provided with a PNP connectivity triode. The control circuit can pull a base electrode drive point to drop to 3.0 volt or be lower than 3.0 volt, so that a current-limiting resistor can be embedded between the base electrode drive point and a base electrode of the PNP connectivity triode. The control circuit comprises a pair of small-value capacitors which is used for providing stable operation for different output capacitors. The control circuit and a p-channel transistor can be used together.
Description
Technical field
The present invention relates to a control circuit, it is used for providing low voltage difference to regulate in the series voltage regulating circuit.More particularly, the present invention relates to three ends and control, for driving a discrete PNP triode or p-channel transistor, to provide a low voltage difference anodal series voltage regulator circuit.
Background technology
The series voltage regulator circuit needs the voltage difference between a minimum supply voltage and voltage stabilizing output voltage, so that suitable regulation and control to be provided.This minimum voltage difference is as the pressure reduction of adjuster circuit.The voltage regulator circuit with low voltage difference has many useful purposes.
Normally, the base drive terminal directly is connected with the base stage of discrete PNP triode the design idea of three end integrated circuit (IC) control device in the PNP voltage stabilizer.This has improved the voltage available in feed circuit to greatest extent, and this must use the base drive end as a supply voltage.Therefore, the general design of circuit is not that the voltage of base drive end is brought up to and is greater than 0 volt lower than the voltage stabilizing input voltage.
In some voltage stabilizer application, it may be to wish to use FET as turn-on transistor.Yet such application may need FET, the grid voltage of this FET is pulled to and approaches ground connection (for example, create the grid of several volts---source voltage is poor).The design of conventional regulator control circuit is operation by this way not, as discussed above.
The design of three end IC control circuits (to a positive-negative-positive voltage stabilizer), the output current of voltage stabilizer and input voltage can not be detected as the purpose of current limliting.This is because the sensing of arbitrary type needs extra terminal.Therefore, the IC internal base drives the current-limiting points of current-limiting circuit must be set up on the prospective current gain and expection voltage stabilizer output current based on discrete triode, to avoid the voltage stabilizer operating conditions, surpasses the electric current of discrete PNP triode and the restriction of rated power.
But, if the user has selected a discrete PNP triode, it is unpredictable that protection will become, it is desired that the current gain that this triode is different and the characteristic of rated power have surpassed manufacturer.For example, the user may select a PNP triode, can not in maximum ideal base drive current, operate safely, and this electric current is controlled by the inside current-limiting circuit of control circuit.
The Similar Problems produced with respect to frequency compensated circuit.An IC regulator control circuit can be used in various application circuits, and application circuit has output capacitance and the equivalent series resistance (ESR) of extensive different capacitances.Yet the frequency compensated circuit in conventional IC regulator control circuit provides stability in a scope limited in output capacitance usually.
Therefore, this will likely provide three terminal voltage regulator control circuits, and this circuit can be used in low dropout voltage regulator design, and wherein the current limliting in different PNP turn-on transistors and different application can be adjusted.This will be further by desirable, if control circuit can bear the output capacitance of wide region, and if this control circuit can provide for a FET turn-on transistor grid of several volts---source drive voltage in a low voltage circuit.
Documents, patent of invention: electric power management circuit and frequency compensation method thereof, application number: 200810088822.4
Summary of the invention
An object of the present invention is to provide a kind of three end control circuits, be used for driving a PNP turn-on transistor in voltage regulator circuit, this circuit has a low voltage difference and controllable current limiting.
Another object of the present invention is to provide a kind of frequency compensated circuit, and it can be combined to provide stability with the voltage regulator circuit output capacitance of different size in adjuster circuit.
Another object of the present invention is to provide a kind of three terminal regulator control circuit, when source voltage is limited to a low input, can drive a p-channel transistor.
Control circuit is designed to when a base drive terminal voltage is less than 3 volts saturated, under some low current conditions, preferentially select lower than 1.1 volts, such resistance can be embedded between base drive end and PNP transistor base, thereby the power consumption in restriction voltage stabilizer output current and control circuit, and make the p-channel fet can be used as turn-on transistor.
Technical solution of the present invention
Frequency compensated circuit in low dropout voltage regulator, voltage modulator circuit comprises a drive end, a feedback end and an earth terminal, a differential signal circuit for generating that is connected to feedback end and earth terminal, it has an output node at the collector of PNP triode, frequency compensated circuit comprises: the first capacitor-coupled is between output node and NPN transistor base, and it descends the gain of differential signal circuit for generating; The second capacitor-coupled is between NPN transistor base and feedback end, and it provides a zero point, can cancel the limit that the frequency when allowing the voltage stabilizer loop gain well below unit 1 produces by the first capacitor.
Frequency compensated circuit in described low dropout voltage regulator, band-gap circuit when described differential signal produces circuit, comprise: a differential amplifier comprises a PNP triode, its emitter-coupled is to feedback end, collector coupled is to output node, the one a NPN triode, its emitter-coupled is to earth terminal, collector coupled is to output node, wherein differential amplifier produces a differential signal at output node, comprise the error between the electric current transmitted by a PNP triode and a NPN triode, differential signal causes voltage modulator circuit at the electrical voltage point of expectation regulation output voltage fully, the 2nd NPN triode, it has an emitter---base circuit, with the base stage in a NPN triode in serial loop---the emitter circuit coupling, serial loop comprises the first resistance between the emitter that is coupling in the first and second NPN triodes, the collector of the 2nd NPN triode is coupled to feedback end by least one impedor, such the first and second NPN triodes are delivered current in proportion, along with the variation of the electric potential difference between feedback end and earth terminal, changes, the base stage of the 2nd PNP triode is coupled to the base stage of a PNP triode, its emitter-coupled is to feedback end, the emitter of the 2nd PNP triode---collector circuit and between feedback end and earth terminal at least one impedor series coupled, wherein the first and second PNP triodes make from the electric current of feedback end a fixing ratio roughly, and the level of electric current is along with the variation of electric potential difference between feedback end and earth terminal responsively changes, wherein, differential signal is produced by differential amplifier, along with the variation of the electric potential difference between feedback end and earth terminal, responsively change, and be coupled to feedback end by least one impedor of the 2nd NPN transistor collector, and and the emitter of the 2nd PNP triode---collector circuit is coupled in series between feedback end and earth terminal, contributes to the setting of the required regulation voltage point of voltage regulator.
Frequency compensated circuit in described low dropout voltage regulator, also comprise the resistance of one and the second capacitances in series coupling between a NPN transistor base and feedback end, and resistance provides electrostatic discharge (ESD) protection for the second electric capacity.
Frequency compensated circuit in described low dropout voltage regulator, the collector of described the 2nd NPN triode is coupling in feedback end by least one impedor, and this impedor can be coupled in series in collector---the emitter circuit of the 2nd PNP triode between feedback end and earth terminal.
Frequency compensated circuit in described low dropout voltage regulator, described differential signal produces circuit and comprises second resistance that is coupled to a NPN transistor base, and the electric capacity of it and the first capacitor joins together to arrange the pole frequency of the first capacitor.
Frequency compensated circuit in described low dropout voltage regulator, differential signal produces circuit and comprises the 3rd resistance be coupling between the 2nd NPN transistor base and collector, is used for balanced differential to produce the electric current in circuit.
Control circuit also comprises a frequency compensated circuit, can be implemented when the internal capacitance of neither one higher value, and provide stability in the mu balanced circuit in having different output capacitors.
The accompanying drawing explanation
Above or other purpose and the advantage of the present invention will occur in detailed below description, and by reference to the accompanying drawings:
Fig. 1 is the schematic diagram according to the control circuit of an application circuit of the principle design of invention;
Fig. 2 is the simplified block diagram of the control circuit of the invention process case;
Fig. 3 is the schematic diagram that the preferred control circuit of the present invention is implemented.
Embodiment
Fig. 1 has illustrated the example application circuit 100 of voltage regulator control circuit in desired type of the present invention.The configuration of application circuit 100 is as an anodal serial regulating circuit.When a unregulated anodal input voltage VIN is applied to voltage input node 102 (with regard to the voltage of earth point 106 and Yan Shizheng), voltage modulator circuit 100 provides an anodal output voltage VO UT who regulated (being also positive with regard to earth point 106 extra voltages) for the load be connected on Voltage-output node 104.In Fig. 1, a simple ohmic load RL is meaned by resistance 108.
Current-limiting resistance 130, it is optional, for the ideal base drive current of PNP triode 120 provides a controllable restriction, can adapt to different input voltages and different PNP triodes.The value of resistance 130 can be selected, for a given input voltage provides a required cut-off current.For example, suppose that output resistance VOUT is suddenly lower than the value that causes that due to the overload situation regulator 100 is regulated.Control circuit 110 will, by a large ideal base drive current IDR is cut into to drive end, be attempted 120 conductings of PNP triode.This electric current will produce one by the voltage of resistance 130.When ideal base drive current increases, will reach a point, now the voltage Drive and Control Circuit 110 by resistance 130 enters saturated.The saturated restriction of the controlled circuit of ideal base drive current.
Suppose the forward base stage of saturation voltage and the PNP triode 120 of control circuit 110---it is approximately 2 volts that emitter voltage drop is added up, the value of current-limiting resistance 130 is chosen to provide a required ideal base drive current IDR at an easy rate, by following formula: RPL=(VMIN-2)/IDR, wherein VMIN is the minimum expectation input voltage.
Conventional regulator control circuit design idea is that drive end is operated in the approximately voltage stabilizer input voltage of 1 volt.This design does not need a current-limiting resistance, and the very little resistance of other probable values, as shown in Figure 1, does not need to increase considerably the pressure drop of voltage stabilizer.
The design control circuit 110 that the applicant has conceived, allow the saturation voltage of drive end low approximately 1.1 volts.This makes current-limiting resistance that a wider scope (for example 20-110 ohm) be arranged, and it is embedded between drive end and PNP transistor base, maintains a low pressure drop simultaneously.Although the applicant prefers such low saturation voltage, the applicant thinks that effective current limliting (being the miserable situation that current limliting avoids the PNP triode to damage under lower than high input voltage and output short-circuit condition) can reach higher saturation voltage.For example, applicant's imagination, at the electric current of principle restriction according to the present invention, the control circuit voltage stabilizer voltage that can realize having the saturation voltage up to 3 volts is 5 volts.
In yet another aspect, feature of the present invention is a frequency compensated circuit, and when control circuit uses from different output capacitor, it can be realized in control circuit so that stability to be provided.This is by providing a preposition scheme that combines the capacitor that feeds back and comprise one group of little value to complete, and will cause that the regulator loop gain is reduced to well below 0 decibel before high-frequency is steady.Therefore, circuit allows enough phase places and gain range to tolerate the output capacitance of a wide region.
Fig. 2 shows with the form of block diagram, and a typical control circuit system is applicable to the control circuit 110 in the present invention.Control circuit 110 comprises a differential amplifier circuit 200, and it has an inverting input that is connected to feedback end FB, and a non-inverting input that is connected to reference circuits 210.Differential amplifier circuit 200 is produced the voltage of terminal FB and one fixed voltage by reference circuit 210 compares, and provides a differential signal for driving circuit 220.This differential signal is controlled driving circuit 220, wherein, in response to differential signal, at control circuit, drives and earth terminal transmission drive current.Control circuit 110 also comprises that an internal base drives current-limiting circuit 230, and the electric current that its restriction is transmitted by driving circuit 220 is a predetermined value, and when the working temperature of control circuit 110 surpasses threshold temperature, driving circuit 220 cuts out.
Fig. 3 has shown a preferred version of circuit, in an integrated device electronics with Fig. 2 general structure, for realizing control circuit 110 of the present invention.The purpose of this particular implementation is to provide a stable output voltage that is approximately 5 volts.This circuit generally includes three parts: a promoter region, a bias area and a control zone.
The purpose of promoter region is, when voltage difference is passed through driving and earth terminal for the first time, to start control circuit 110 work.Promoter region is included in triode Q1, Q2, Q3 and the Q4A of Fig. 3 left-hand side.Triode Q1 is a crystal type field effect transistor produced by epitaxial growth, and when voltage difference is passed through driving and earth terminal for the first time, it provides electric current for the triode Q2 that connects diode.Triode Q2 is manufactured with higher forward voltage (VBE is approximately 850mV in the time of 25 degrees centigrade).Flow through triode Q2 with little electric current, Q3, then conducting immediately delivered current by resistance R 2 and R3, only when both absorb the electric current from triode Q4A-G common base point simultaneously.This will cause triode Q4A-F conducting, in their base stage---and when emitter circuit is in parallel.The conducting meeting of triode Q4E causes extra electric current flow through resistance R 2 and R3.Extra electric current improves the voltage (by resistance R 2 and R3) of triode Q3 emitter, in order to finally make the base stage of Q3---and the emitter node reverse bias, therefore, after the conducting of Q4A-F triode, cut off promoter region from the circuit remainder.Once control circuit 110 work, the assembly in promoter region be do not have influential.
Further move to the right side of Fig. 3, triode Q5, Q6 and Q7 have formed bias area.These triode biasings PNP triode string Q4A-G provide the substantially invariable electric current from all PNP collectors, even change output/driving voltage.This substantially constant electric current also is used to produce the substantially invariable voltage through resistance R 2 and R3.
This bias area can operate below 1 volt about.Triode Q5 and Q6, be connected to image current configuration upper, has unequal emitter area ratio 10:1, when triode Q5 and Q6 transmit equal electric current, causes that the voltage VBE that is approximately 60mV is by resistance R 1.This voltage, be arranged on biasing triode Q4B-F by electric current upper, has a positive temperature coefficient.The connection of triode Q7 is to be used to provide a backfeed loop.This backfeed loop is guaranteed a substantially invariable electric current, changes the voltage of drive end simultaneously.Capacitor C 1 is used to backfeed loop that frequency compensation is provided.
The control zone of control circuit 110 is that band gap is with reference to type, and comprising reference voltage generator and the differential amplifier circuit (corresponding to the zone 200 and 210 of Fig. 2) of a combination, it drives a current gain level (corresponding to the drive circuit area 220 of Fig. 2).More particularly, the active component that has formed band-gap circuit at the triode Q15-20 on Fig. 3 right side.The output driving current gain stage triode Q12 of the circuit of this band gap type, Q9 and Q10, this is the base drive of Drive and Control Circuit point (being drive end) again conversely.Fig. 3 band-gap circuit is that the electric current by the feedback end (FB) from controlling circuit 110 provides energy.Total institute is known, therefore only simply discusses here, and a band-gap circuit is worked with the reference voltage that a temperature stabilization is provided by balance positive pole and negative pole temperature coefficient.In Fig. 3, when voltage is applied on the FB terminal, electric current flow to triode/resistance string R9, Q19 (diode connects), Q18 (and relevant biasing resistor R10 and R11), Q17 (diode connects), R13, Q16 and R15.By means of the image current device of triode Q19 and Q20, equal electric current will flow through resistance R 8 and triode Q20.Through the electric current of triode Q19 and Q20, and resistance R 9, the voltage of R13 and R16, have positive temperature coefficient (PTC), offset the base stage of triode Q16-Q19---the negative temperature coefficient in emitter voltage.
Triode Q15 and Q20 are as a differential amplifier, and its output is a differential signal, in the collector appearance of triode Q15.The voltage of this node forces compacting as current-limiting protection by triode Q13, as following, is discussed.
Along with feedback terminal place voltage rises, the triode of flowing through/resistance string R9, Q19, Q18, Q17, R13, Q16, the electric current of R16, and the electric current of process resistance R 8 and triode Q20, equivalent addition.Yet, when electric current improves the voltage VBE of process resistance R 16, will cause that the current ratio of triode Q16 and Q15 reduces, for example the collector voltage of triode Q15, be high at first, starts to reduce.When the pressure drop by resistance R 16 reaches about 60mV, the current ratio between triode Q15 and Q16 becomes about 1:1.Control circuit 110 is designed to regulate this point, this equates the voltage of one 5 volts of feedback ends.
The voltage of triode Q15 collector drives by triode Q12, Q9 and Q10 and biasing resistor R4, the current gain level that R5 and R6 form.Triode Q12, it receives the working current from triode Q14 and Q4F, penetrates level as one and follows impact damper.When the voltage of feedback end is less than 5 volts, it is high that the collector voltage of triode Q15 keeps base stage and the emitter voltage of triode Q12, and this causes again output to drive triode Q9 and Q10 from the drive end Absorption Current conversely.When driving, the output terminal of triode Q9 and Q10 can make the lower voltage of drive end to being less than 1.5 volts, and drive current is 10mA.This saturation voltage rises to about 2 volts when drive current is 150mA.Therefore, the current-limiting resistance of an outside can be embedded between the drive end and discrete PNP triode of control circuit 110, is used for limiting ideal base drive current, and the pressure drop that does not improve voltage regulator circuit.The value of resistance, as front discussion, can be selected.
If the voltage of feedback end rises to 5 volts, the voltage of triode Q15 collector, to lower swing, offers the driving signal of Q9 and Q10 thereby reduce, and causes control circuit to infilter ideal base drive current still less from drive end.Control circuit 110 can easily be modified regulation voltage rather than 5 volts.Applicant imagination, Fig. 3 circuit structure can be used to regulate cathode voltage, at 15 volts to the scope that is low to moderate 2.5 volts, in the basic structure of the circuit that only has slight variation.The scope of regulating is by revising triode Q17 and Q18 and resistance R 10, and the I/V characteristic of R11 and R13 realizes.These elements can be counted as being referred to as and comprise an adjustable impedor 300 (shown in Fig. 3), and this is the purpose that required regulation voltage is set.In order to reduce regulation voltage, for example, one or two can be removed triode Q17 and Q18, and biasing resistor R10 and R11 (it increases the pressure drop through triode Q18) can be removed or change, or the resistance of R13 can be lowered.
The impedor 300 of standard can be a simple resistance or a resistance combination, triode and diode or similar, and selected pressure drop of therefore passing it can produce suitable required regulation voltage.Yet, should keep firmly in mind, when selecting specific element, form the impedor 300 of standard, the temperature drift of this circuit may be affected.The elements combination zone should be such, and the required temperature drift (being generally zero) of control circuit obtains when voltage is required regulation voltage.
Should also be pointed out that, for example, for lower regulation voltage (2.85 volts), due to the base voltage of Q12 by the parasitic collector of triode Q20---base diode remains low-voltage, the problem of a startup may run into, and it can be dragged down by resistance or the triode that comprises triode Q19.For fear of this problem, from the drive end power supply, can when starting, provide current to base stage and the collector of triode Q12, thereby triode Q9 and Q10 are switched on.
Under the frequency of a permission regulation loop gain unit of being far smaller than 1, this zero zero point of having offset by capacitor C 2 generations.This provides phase margin for the output capacitance that allows a wide region.Zero frequency, the resistance of the impedance of element 300 and resistance R 15 and R16 is determined by the capacitance of capacitor C 3.The suitable value of capacitor C 2 and C3 can determine by rule of thumb.Resistance R 12 has been added to capacitor C3 so that esd protection to be provided.
The feature of control circuit 110 some other aspects is significant.Referring again to arriving triode Q4F, triode is assisted the startup of control circuit.When starting, triode Q14 does not provide electric current (voltage of supposing feedback terminal FB is low).Triode Q4F, by the drive end power supply, therefore be used for driving the base stage of triode Q10 that electric current is provided to output, to start to drive outside PNP turn-on transistor.Triode Q14 can remove from circuit.Yet it provides an extra current limit foldback function.If the output short-circuit of voltage stabilizer, triode Q14 will be closed.In the normal operation period, this triode provides the approximately working current of 3/4ths (75 microamperes) for triode Q10 and Q12.Therefore, the drive current that output short-circuit causes triode Q10 to use is showing and is reducing, thereby effectively turns back the restriction of control circuit internal current.Triode Q4G provides the purpose of clamping plate and keeps triode Q4F unsaturated, and this can upset the bias voltage of other PNP triode in the biasing string.Resistance R 6 is added on out drive stage and stops high frequency oscillation.Triode Q13 provides an internal current restriction, and its working method is as follows.Base stage on triode Q13---the little electric current of emitter node common reverse bias triode Q9 and Q10, because pass the base voltage of the voltage of resistance R 2 and R3 higher than triode Q12, the base stage of Q12 is connected with the emitter of Q13.Yet; for larger electric current, the base stage of triode Q13---emitter node forward bias, thereby turn-on transistor Q12; this will cause electric current, and it can force the base stage of triode Q12 to uprise then ground connection by the collector of triode Q13 usually, thereby produces clamping action.Inner cut-off current is set by the value of resistance R 4.In the concrete enforcement of Fig. 3, inner current-limiting circuit is 170mA at the drive end Limited Current.
The heat protection is provided by triode Q8, if surpass threshold temperature, it makes the base stage of electric current away from Q10.The voltage of triode Q8 base stage has positive temperature coefficient (PTC).Triode Q8 base stage---emitter node has a negative temperature coefficient.Triode Q8 conducting at the about temperature of 165 degrees centigrade.
Therefore, a kind of new voltage regulator control circuit has produced.Technician in the art will be understood that, outside the feasible described embodiment of the present invention, and various supplementary elements in side circuit and substitute contact each other, though not shown in the drawings, can use.Described concrete enforcement presents as purpose rather than limits, and the present invention is limited by claim only.
Claims (6)
1. the frequency compensated circuit in low dropout voltage regulator, it is characterized in that: voltage modulator circuit comprises a drive end, a feedback end and an earth terminal, a differential signal circuit for generating that is connected to feedback end and earth terminal, it has an output node at the collector of PNP triode, frequency compensated circuit comprises: the first capacitor-coupled is between output node and NPN transistor base, and it descends the gain of differential signal circuit for generating; The second capacitor-coupled is between NPN transistor base and feedback end, and it provides a zero point, can cancel the limit that the frequency when allowing the voltage stabilizer loop gain well below unit 1 produces by the first capacitor.
2. the frequency compensated circuit in low dropout voltage regulator according to claim 1 is characterized in that: band-gap circuit when described differential signal produces circuit comprises:
A differential amplifier comprises a PNP triode, its emitter-coupled is to feedback end, collector coupled is to output node, the one a NPN triode, its emitter-coupled is to earth terminal, collector coupled is to output node, wherein differential amplifier produces a differential signal at output node, comprise the error between the electric current transmitted by a PNP triode and a NPN triode, differential signal causes voltage modulator circuit at the electrical voltage point of expectation regulation output voltage fully;
The 2nd NPN triode, it has an emitter---base circuit, with the base stage in a NPN triode in serial loop---the emitter circuit coupling, serial loop comprises the first resistance between the emitter that is coupling in the first and second NPN triodes, the collector of the 2nd NPN triode is coupled to feedback end by least one impedor, such the first and second NPN triodes are delivered current in proportion, along with the variation of the electric potential difference between feedback end and earth terminal, changes;
The base stage of the 2nd PNP triode is coupled to the base stage of a PNP triode, its emitter-coupled is to feedback end, the emitter of the 2nd PNP triode---collector circuit and between feedback end and earth terminal at least one impedor series coupled, wherein the first and second PNP triodes make from the electric current of feedback end a fixing ratio roughly, and the level of electric current is along with the variation of electric potential difference between feedback end and earth terminal responsively changes; Wherein, differential signal is produced by differential amplifier, along with the variation of the electric potential difference between feedback end and earth terminal, responsively change, and be coupled to feedback end by least one impedor of the 2nd NPN transistor collector, and and the emitter of the 2nd PNP triode---collector circuit is coupled in series between feedback end and earth terminal, contributes to the setting of the required regulation voltage point of voltage regulator.
3. the frequency compensated circuit in low dropout voltage regulator according to claim 2; it is characterized in that: also comprise the resistance of one and the second capacitances in series coupling between a NPN transistor base and feedback end, resistance provides electrostatic discharge (ESD) protection for the second electric capacity.
4. the frequency compensated circuit in low dropout voltage regulator according to claim 3, it is characterized in that: the collector of described the 2nd NPN triode is coupling in feedback end by least one impedor, and this impedor can be coupled in series in collector---the emitter circuit of the 2nd PNP triode between feedback end and earth terminal.
5. the frequency compensated circuit in low dropout voltage regulator according to claim 4, it is characterized in that: described differential signal produces circuit and comprises second resistance that is coupled to a NPN transistor base, and the electric capacity of it and the first capacitor joins together to arrange the pole frequency of the first capacitor.
6. the frequency compensated circuit in low dropout voltage regulator according to claim 5, it is characterized in that: differential signal produces circuit and comprises the 3rd resistance be coupling between the 2nd NPN transistor base and collector, is used for balanced differential to produce the electric current in circuit.
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| Application Number | Priority Date | Filing Date | Title |
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| CN2013202164045U CN203324874U (en) | 2013-04-24 | 2013-04-24 | Frequency compensating circuit of low dropout voltage regulator |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103207637A (en) * | 2013-04-24 | 2013-07-17 | 苏州硅智源微电子有限公司 | Frequency compensating circuit in voltage stabilizer with low voltage drop |
| CN106292823A (en) * | 2016-08-31 | 2017-01-04 | 苏州纳芯微电子股份有限公司 | A kind of high-low pressure converts integrated circuit |
-
2013
- 2013-04-24 CN CN2013202164045U patent/CN203324874U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103207637A (en) * | 2013-04-24 | 2013-07-17 | 苏州硅智源微电子有限公司 | Frequency compensating circuit in voltage stabilizer with low voltage drop |
| CN106292823A (en) * | 2016-08-31 | 2017-01-04 | 苏州纳芯微电子股份有限公司 | A kind of high-low pressure converts integrated circuit |
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Granted publication date: 20131204 Termination date: 20140424 |