CN109217829B - Error amplifier rapid closed-loop system for field effect transistor - Google Patents
Error amplifier rapid closed-loop system for field effect transistor Download PDFInfo
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- CN109217829B CN109217829B CN201810831864.6A CN201810831864A CN109217829B CN 109217829 B CN109217829 B CN 109217829B CN 201810831864 A CN201810831864 A CN 201810831864A CN 109217829 B CN109217829 B CN 109217829B
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- error amplifier
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- effect transistor
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/34—Negative-feedback-circuit arrangements with or without positive feedback
- H03F1/342—Negative-feedback-circuit arrangements with or without positive feedback in field-effect transistor amplifiers
Abstract
The invention discloses a fast closed-loop system of an error amplifier aiming at a field effect tube, which comprises an application circuit, the field effect tube and the error amplifier, wherein the feedback input end of the error amplifier is correspondingly connected with the application circuit, and the output end of the error amplifier is correspondingly connected with the grid electrode of the field effect tube; the field effect tube is correspondingly connected with the application circuit; and the power supply end of the error amplifier is correspondingly connected with a slow starting circuit. The power supply end of the error amplifier is correspondingly connected with the slow starting circuit, so that the output change rate of the error amplifier in the starting stage can be effectively reduced, and the grid of the field effect tube can be rapidly closed when reaching a working point; after the power supply of the error amplifier is stable, the bandwidth of a control loop is not influenced, and the real-time tracking of the feedback voltage on the reference control voltage can be ensured.
Description
Technical Field
The invention relates to the technical field of electrical control, in particular to a fast closed-loop system of an error amplifier for a field-effect tube.
Background
The field effect transistor has strong nonlinear characteristics from control to output, only a narrow middle region is approximate to a linear region, when the field effect transistor is used for electrical control in the linear region, a negative feedback circuit is formed on the basis of an error amplifier, and closed-loop control is realized by adjusting the grid voltage of the field effect transistor. In order to shorten the closed loop time of the error amplifier from start-up to entering a steady state, the prior art adopts a method of adjusting the input control reference from zero.
When the prior art is applied for starting, the output of the error amplifier drives the grid voltage of the field effect transistor to increase from zero along with the adjustment of the input control reference from zero. When the grid voltage of the field effect transistor is lower than the starting voltage, the field effect transistor is always in a cut-off state, and the feedback input of the error comparator is always zero. After a period of time, the output of the error comparator drives the gate of the fet to a turn-on voltage, at which time the control reference has also risen to Δ r. Because the amplification factor of the error amplifier is large, the output is enabled to rise at a fast speed under the input error delta r, so that the grid voltage is greatly overshot at the closed-loop working point, the closed-loop speed is controlled, and even the control failure is caused.
Disclosure of Invention
Based on the above defects in the prior art, embodiments of the present invention provide a fast closed-loop system for an error amplifier of a field effect transistor, which can implement fast closed-loop of the error amplifier and effectively avoid output overshoot at the start-up stage.
The present invention can be implemented in numerous ways, including as a method, system, device, apparatus, or computer readable medium in which several embodiments of the invention are discussed below.
A fast closed-loop system of an error amplifier aiming at a field effect transistor comprises an application circuit, the field effect transistor and the error amplifier, wherein the feedback input end of the error amplifier is correspondingly connected with the application circuit, and the output end of the error amplifier is correspondingly connected with the grid electrode of the field effect transistor; the field effect tube is correspondingly connected with the application circuit; and the power supply end of the error amplifier is correspondingly connected with a slow starting circuit.
Further, the slow starting circuit comprises a voltage slope type slow starting circuit and a current slope type slow starting circuit.
Further, the negative input end of the error amplifier is a feedback input end, and the input of the negative input end is a feedback value of the controlled electrical quantity of the application circuit.
Further, the positive input end of the error amplifier is a reference input end, and the input of the positive input end of the error amplifier is a reference control voltage.
The positive beneficial technical effects which can be realized by the embodiment of the invention comprise: the power supply end of the error amplifier is correspondingly connected with the slow starting circuit, so that the output change rate of the error amplifier in the starting stage can be effectively reduced, and the grid of the field effect tube can be rapidly closed when reaching a working point; after the power supply of the error amplifier is stable, the bandwidth of a control loop is not influenced, and the real-time tracking of the feedback voltage on the reference control voltage can be ensured; the circuit structure is simple and easy to realize.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
Drawings
The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
fig. 1 is a structural diagram of a fast closed-loop system of an error amplifier for a field effect transistor according to an embodiment of the present invention;
FIG. 2 is a circuit diagram of a control system according to an embodiment of the present invention;
FIG. 3 is a waveform diagram of a start-up simulation according to an embodiment of the present invention.
Detailed Description
All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.
Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.
Fig. 1 is a structural diagram of a fast closed-loop system of an error amplifier for a field effect transistor according to an embodiment of the present invention, as shown in fig. 1, the fast closed-loop system includes an application circuit, a field effect transistor, and an error amplifier, where an input end of the error amplifier is correspondingly connected to the application circuit, and an output end of the error amplifier is correspondingly connected to a gate of the field effect transistor; the field effect tube is correspondingly connected with an application circuit; the power supply end of the error amplifier is correspondingly connected with a slow starting circuit, and the power supply voltage adopts slow starting voltage.
The slow starting circuit comprises a voltage slope type slow starting circuit and a current slope type slow starting circuit, and is mainly used for (1) anti-jitter delay power-on; (2) the rising slope and amplitude of the output voltage are controlled. The error amplifier is powered by adopting slow start voltage, the output amplitude of the error amplifier is limited by limiting the amplitude and the change rate of the power supply voltage, and the change rate of the grid voltage of the field effect transistor is reduced.
The negative input end of the error amplifier is a feedback input end, and the input of the negative input end is a feedback value of the controlled electrical quantity of the application circuit; the positive input end is a reference input end, and the input of the positive input end is a reference control voltage. After the power supply voltage of the error amplifier is stable, the bandwidth of a control loop is not affected, and the real-time tracking of the feedback voltage on the reference control voltage is realized.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
Fig. 2 is a circuit diagram of a control system according to an embodiment of the present invention, and as shown in fig. 2, the application circuit is composed of a dc power supply Vdc, a load capacitor C, and a field-effect transistor Q1, and the controlled electrical quantity is a charging current i from the dc power supply Vdc to the load capacitor C. The resistors R3, R4 and the operational amplifier U constitute an error amplifier. The zener diode D is pulled up to 12V through the current limiting resistor R2 and the generated reference control voltage is used as input to the positive input of the operational amplifier U. The charging current i feedback quantity is input to the negative input end of U through R3. The output of U is connected to Q1, controlling its gate voltage. The resistor R1, the capacitors C1, C2 and the triode Q2 form a power supply slow start circuit, and power is supplied to U slow start through the emitter of Q2.
Fig. 3 is a start-up simulation waveform diagram of the specific embodiment, and it can be known from analysis of the simulation waveform diagram that the control system shown in fig. 2 is used to implement fast closed-loop control of the error amplifier, and limit the output amplitude of the error amplifier by limiting the amplitude and the change rate of the supply voltage, and reduce the change rate of the gate voltage of the field effect transistor.
The different aspects, embodiments, implementations or features of the invention can be used alone or in any combination.
The invention is not limited to the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this specification and any novel method or process steps or any novel combination of features disclosed.
Claims (4)
1. A fast closed loop system of an error amplifier aiming at a field effect transistor is characterized by comprising an application circuit, the field effect transistor and the error amplifier, wherein the feedback input end of the error amplifier is correspondingly connected with the application circuit, and the output end of the error amplifier is correspondingly connected with the grid electrode of the field effect transistor; the field effect tube is correspondingly connected with the application circuit; the power supply end of the error amplifier is correspondingly connected with a slow starting circuit;
the application circuit consists of a direct-current (3) power supply Vdc, a load capacitor C and a field-effect tube Q1, and the controlled electric quantity is charging current i from the direct-current power supply Vdc to the load capacitor C; the resistors R3 and R4 and the operational amplifier U form an error amplifier; the voltage stabilizing diode D is pulled up to 12V through a current limiting resistor R2, the generated reference control voltage is used for being input to the positive input end of an operational amplifier U, the feedback quantity of the charging current i is input to the negative input end of the U through R3, the output of the U is connected with Q1, and the grid voltage of the U is controlled; the resistor R1, the capacitors C1, C2 and the triode Q2 form a power supply slow start circuit, and power is supplied to U slow start through the emitter of Q2.
2. The fast closed-loop system for the error amplifier of the field effect transistor as claimed in claim 1, wherein the soft start circuit comprises a voltage slope type soft start circuit and a current slope type soft start circuit.
3. The fast closed-loop system of the error amplifier for the field effect transistor as claimed in claim 1, wherein the negative input terminal of the error amplifier is a feedback input terminal, and the input terminal is a feedback value of the controlled electrical quantity of the application circuit.
4. The fast closed-loop system for the error amplifier of the field effect transistor as claimed in claim 1, wherein the positive input terminal of the error amplifier is a reference input terminal, and the input of the reference input terminal is a reference control voltage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810831864.6A CN109217829B (en) | 2018-07-26 | 2018-07-26 | Error amplifier rapid closed-loop system for field effect transistor |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810831864.6A CN109217829B (en) | 2018-07-26 | 2018-07-26 | Error amplifier rapid closed-loop system for field effect transistor |
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| CN109217829A CN109217829A (en) | 2019-01-15 |
| CN109217829B true CN109217829B (en) | 2021-05-14 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101373926A (en) * | 2007-08-24 | 2009-02-25 | 尼克森微电子股份有限公司 | Pulse-width modulation controller for switching voltage stabilizer |
| CN102023668A (en) * | 2010-11-02 | 2011-04-20 | 深圳市富满电子有限公司南山分公司 | Linear voltage adjuster circuit |
| KR20130021840A (en) * | 2011-08-24 | 2013-03-06 | 삼성전자주식회사 | Soft start apparatus and converter apparatus using thereof |
| CN103529890A (en) * | 2012-07-06 | 2014-01-22 | 国民技术股份有限公司 | Soft start device and method |
| CN205453486U (en) * | 2016-03-25 | 2016-08-10 | 深圳市陆巡天下科技有限公司 | Novel switching power supply delays starting circuit |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3169002B2 (en) * | 1998-12-18 | 2001-05-21 | 日本電気株式会社 | Transmission output control circuit |
| US6943504B1 (en) * | 2003-11-24 | 2005-09-13 | National Semiconductor Corporation | Open loop magnetic boost LED driver system and method |
| US7619397B2 (en) * | 2006-11-14 | 2009-11-17 | Texas Instruments Incorporated | Soft-start circuit for power regulators |
| CN203617899U (en) * | 2013-12-16 | 2014-05-28 | 四川升华电源科技有限公司 | Improved soft start apparatus for rapid discharge and constant-current charge |
| CN107204705B (en) * | 2016-03-18 | 2019-04-19 | 电信科学技术研究院 | The control method of DC-DC adjuster and its soft start, controller |
| CN106155159B (en) * | 2016-08-19 | 2018-03-23 | 重庆西南集成电路设计有限责任公司 | Multiplex circuit and error amplifier and multiple-channel output low pressure difference linear voltage regulator |
-
2018
- 2018-07-26 CN CN201810831864.6A patent/CN109217829B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101373926A (en) * | 2007-08-24 | 2009-02-25 | 尼克森微电子股份有限公司 | Pulse-width modulation controller for switching voltage stabilizer |
| CN102023668A (en) * | 2010-11-02 | 2011-04-20 | 深圳市富满电子有限公司南山分公司 | Linear voltage adjuster circuit |
| KR20130021840A (en) * | 2011-08-24 | 2013-03-06 | 삼성전자주식회사 | Soft start apparatus and converter apparatus using thereof |
| CN103529890A (en) * | 2012-07-06 | 2014-01-22 | 国民技术股份有限公司 | Soft start device and method |
| CN205453486U (en) * | 2016-03-25 | 2016-08-10 | 深圳市陆巡天下科技有限公司 | Novel switching power supply delays starting circuit |
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| CN109217829A (en) | 2019-01-15 |
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