CN220775656U - Constant current control device - Google Patents
Constant current control device Download PDFInfo
- Publication number
- CN220775656U CN220775656U CN202320831855.3U CN202320831855U CN220775656U CN 220775656 U CN220775656 U CN 220775656U CN 202320831855 U CN202320831855 U CN 202320831855U CN 220775656 U CN220775656 U CN 220775656U
- Authority
- CN
- China
- Prior art keywords
- resistor
- error amplifier
- conversion chip
- current
- inductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000006243 chemical reaction Methods 0.000 claims abstract description 19
- 238000005070 sampling Methods 0.000 claims abstract description 12
- 230000001360 synchronised effect Effects 0.000 description 4
- 230000003321 amplification Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model aims to provide a constant current control device which has a simple structure and can control the magnitude of an external input current. The utility model comprises a buck conversion chip, an inductor, a diode, an operational amplifier, an error amplifier and a sampling resistor, wherein a SW pin of the buck conversion chip is connected with one end of the inductor, the other end of the inductor is connected with the cathode of the diode through the sampling resistor, the anode of the diode is connected with a constant voltage source, a FB pin of the buck conversion chip is connected with the output end of the error amplifier, the anode input end of the error amplifier is connected with an input voltage source, the cathode input end of the error amplifier is connected with the output end of the operational amplifier, and the input end of the operational amplifier is connected with the sampling resistor. The utility model is applied to the technical field of constant flow control.
Description
Technical Field
The utility model is applied to the technical field of constant flow control, and particularly relates to a constant flow control device.
Background
The SINK loop refers to that under the normal condition, for a synchronous Buck step-down circuit, the input voltage is higher than the output voltage, and the chip is in a CV_Source state to provide current for external constant voltage; when the external voltage is higher than the output voltage, the current reversely flows into the control loop, and the loop is in the SINK state, and the loop model is a Boost model. The constant current control means that when the current is in the SINK state, the current can be infinitely increased because the current limiting circuit is not provided, and when the feedback control loop is added, the SINK current is at a settable current value, and thus the controllable constant current is realized. In the measurement circuit, the most common is a constant current control circuit and a constant voltage control circuit in a Buck mode, and most Buck chips are internally provided with feedback and compensation loops, and the constant voltage source can be manufactured after the constant voltage is calculated after voltage division. However, the constant current circuit needs to be controlled by an external added current acquisition circuit, an error comparator circuit and a compensation loop. However, when some circuits are needed to simulate the battery for charging, the Buck constant voltage circuit is difficult to achieve the ideal effect. The synchronous Buck circuit can also work in a Sink state at present, all energy can be fed back to the input end at the moment, so that the current which is poured in can not be controlled, and the voltage source at the current pouring end can easily output current to the maximum if no current limiting protection exists, until the power supply is abnormal. It is therefore necessary to provide a constant current control device that has a simple structure and is capable of controlling the magnitude of an externally input current.
Disclosure of Invention
The utility model aims to solve the technical problem of overcoming the defects of the prior art and providing the constant current control device which has a simple structure and can control the magnitude of external input current.
The technical scheme adopted by the utility model is as follows: the utility model comprises a buck conversion chip, an inductor, a diode, an operational amplifier, an error amplifier and a sampling resistor, wherein a SW pin of the buck conversion chip is connected with one end of the inductor, the other end of the inductor is connected with the cathode of the diode through the sampling resistor, the anode of the diode is connected with a constant voltage source, a FB pin of the buck conversion chip is connected with the output end of the error amplifier, the anode input end of the error amplifier is connected with an input voltage source, the cathode input end of the error amplifier is connected with the output end of the operational amplifier, and the input end of the operational amplifier is connected with the sampling resistor.
According to the scheme, the buck conversion chip and the inductor form a Boost structure for synchronous output, the synchronous buck conversion chip is in a Boost state and allows current to be poured in, the diode ensures that the current has a fixed flow direction, a loop is always in a Sink loop, controllable constant current is realized in the Sink loop through the error amplifier, the constant current control device is only suitable for constant current control in the Sink state, the conversion chip is in the Boost state in the state, the magnitude of external input current can be conveniently controlled only through current collection and the error amplifier, and the external control board can be tested by simulating the battery charging process, so that the problem that the loop current cannot be controlled in the Sink state is solved.
In one preferred scheme, the constant current control device further comprises a first resistor, a second resistor and a third resistor, wherein the FB pin of the buck conversion chip is divided into two paths, one path is grounded through the third resistor, the other path is connected with the output end of the error amplifier through the second resistor, and the cathode input end of the error amplifier is connected with the output end of the operational amplifier through the first resistor.
Drawings
Fig. 1 is a schematic circuit diagram of the present utility model.
Detailed Description
As shown in fig. 1, in this embodiment, the present utility model includes a buck conversion chip, an inductor L1, a diode D1, an operational amplifier OP1, an error amplifier OP2, and a sampling resistor Rs, where a SW pin of the buck conversion chip is connected to one end of the inductor L1, the other end of the inductor L1 is connected to a cathode of the diode D1 through the sampling resistor Rs, an anode of the diode D1 is connected to a constant voltage source CV, a FB pin of the buck conversion chip is connected to an output end of the error amplifier OP2, an anode input end of the error amplifier OP2 is connected to an input voltage source Set, and an cathode input end of the error amplifier OP2 is connected to an output end of the operational amplifier OP1, and an input end of the operational amplifier OP1 is connected to the sampling resistor Rs. The sampling resistor Rs is used for converting current into voltage signals, the operational amplifier OP1 is an instrument operational amplifier with fixed amplification factor and has a certain gain amplification function, and the error amplifier OP2 can feed back the current signals to the FB pin of the buck conversion chip. The input voltage source Set is used for setting the current, the input voltage at the Set end can adjust the current in the loop after passing through the error amplifier OP2 to keep the current constant, and the constant current value and the voltage value of Set have a fixed functional relation, so that the controllable constant current can be realized.
As shown in fig. 1, in this embodiment, the constant current control device further includes a first resistor R1, a second resistor R2, and a third resistor R3, where the FB pin of the buck conversion chip is divided into two paths, one path is grounded through the third resistor R3, the other path is connected to the output end of the error amplifier OP2 through the second resistor R2, and the cathode input end of the error amplifier OP2 is connected to the output end of the operational amplifier OP1 through the first resistor R1. The first resistor R1, the second resistor R2 and the third resistor R3 are all used as compensation resistors, and the comparison voltage value of the clamping circuit can be adjusted.
Claims (2)
1. A constant current control device, characterized in that: the voltage-reducing type DC-DC converter comprises a voltage-reducing type conversion chip, an inductor (L1), a diode (D1), an operational amplifier (OP 1), an error amplifier (OP 2) and a sampling resistor (Rs), wherein an SW pin of the voltage-reducing type conversion chip is connected with one end of the inductor (L1), the other end of the inductor (L1) is connected with a cathode of the diode (D1) through the sampling resistor (Rs), an anode of the diode (D1) is connected with a constant voltage source (CV), an FB pin of the voltage-reducing type conversion chip is connected with an output end of the error amplifier (OP 2), an anode input end of the error amplifier (OP 2) is connected with an input voltage source (Set), and an input end of the error amplifier (OP 2) is connected with an output end of the operational amplifier (OP 1).
2. A constant current control device according to claim 1, characterized in that: the constant current control device further comprises a first resistor (R1), a second resistor (R2) and a third resistor (R3), wherein the FB pin of the buck conversion chip is divided into two paths, one path is grounded through the third resistor (R3), the other path is connected with the output end of the error amplifier (OP 2) through the second resistor (R2), and the cathode input end of the error amplifier (OP 2) is connected with the output end of the operational amplifier (OP 1) through the first resistor (R1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320831855.3U CN220775656U (en) | 2023-04-14 | 2023-04-14 | Constant current control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320831855.3U CN220775656U (en) | 2023-04-14 | 2023-04-14 | Constant current control device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220775656U true CN220775656U (en) | 2024-04-12 |
Family
ID=90605112
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320831855.3U Active CN220775656U (en) | 2023-04-14 | 2023-04-14 | Constant current control device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220775656U (en) |
-
2023
- 2023-04-14 CN CN202320831855.3U patent/CN220775656U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9912236B2 (en) | Soft start switching power supply system | |
| CN101795073B (en) | Method for controlling output current of flyback converter and its relative power inverter | |
| US8085022B2 (en) | Switching regulator and control circuit thereof, and method for determining on-time in switching regulator | |
| CN204068695U (en) | Power conversion system | |
| CN1929274B (en) | Controller and control method for dc-dc converter | |
| CN101702574B (en) | Power factor correcting controller and control method and applied power supply converter thereof | |
| CN101951151B (en) | Dual-mode fully-integrated high-frequency reduction voltage power supply with high light load efficiency | |
| CN107656124B (en) | Boost load current detection circuit and method without external sampling resistor | |
| CN102931841A (en) | Multiphase DC-DC Power Converter | |
| US11737180B2 (en) | Control circuit, chip and control method | |
| CN105429460A (en) | DC-DC converter with line loss compensation function | |
| US7352161B2 (en) | Burst-mode switching voltage regulator with ESR compensation | |
| CN101789682A (en) | Multiple output power supply time sequence control device and method | |
| CN103516203A (en) | DC-DC controller and operation method thereof | |
| CN212850269U (en) | High-power low-noise digital adjustable voltage source | |
| CN107592705A (en) | The LED drive circuit and light-dimming method of tunable optical | |
| CN220775656U (en) | Constant current control device | |
| US11742759B2 (en) | Voltage converter with loop control | |
| CN109327141A (en) | A kind of wide-range voltage and High-current output method and power-supply system | |
| US8476942B2 (en) | Summation circuit in DC-DC converter | |
| CN113098267A (en) | Switch converter, switch integrated circuit and control circuit thereof | |
| CN108988624B (en) | Asynchronous starting circuit | |
| CN111211690A (en) | Power supply circuit | |
| CN105914832B (en) | Adjustable voltage feedback circuit with constant current protection and working method | |
| CN104022645B (en) | The constant frequency of a kind of switch converters fixes turn-off time control device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |