CN219107288U - Constant current hiccup protection circuit - Google Patents
Constant current hiccup protection circuit Download PDFInfo
- Publication number
- CN219107288U CN219107288U CN202222818977.7U CN202222818977U CN219107288U CN 219107288 U CN219107288 U CN 219107288U CN 202222818977 U CN202222818977 U CN 202222818977U CN 219107288 U CN219107288 U CN 219107288U
- Authority
- CN
- China
- Prior art keywords
- resistor
- controller
- pin
- comparator
- reference voltage
- 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
Images
Abstract
The utility model provides a constant-current hiccup protection circuit, which can accurately control the hiccup protection period of output through a timer of a controller when a power supply works in a constant-current state, wherein the positive input end of an operational amplifier U1 is connected with a reference voltage Iref, the negative input end of the operational amplifier U1 is connected with a sampling voltage Isense of output current and one end of a resistor R1, the other end of the resistor R1 is connected with one end of a resistor R3 and the other end of the capacitor C1, the other end of the resistor R3 is connected with one end of a resistor R4 and the positive input end of a comparator U2, the other end of the resistor R4 is connected with a secondary side ground signal AGND, the negative input end of the comparator U2 is connected with a reference voltage +3.3V, the output end of the comparator U2 is connected with one end of a resistor R5 and a time_out pin of the controller U3, the other end of the resistor R5 is connected with a reference voltage +3.3V, and the LLC_pin of the controller U3 is connected with an enabling pin of the power controller.
Description
Technical Field
The utility model relates to the field of switching converters, in particular to a constant current hiccup protection circuit.
Background
Because the application of the power industry is more and more complex, in the occasion that the capacity type load is very big or the motor is applied, the output impact current is very big when the power is started, thereby trigger the overcurrent protection of the power, and in order to solve this problem, constant current control is generated all the time, in the occasion that the capacity type load is very big, the current is limited to a constant value, the output voltage gradually rises until the output impact current ends, the power begins to work in a voltage mode, because under normal circumstances, the power all works in the voltage mode, therefore, the constant current point is bigger than rated current, generally 130% -180% of rated current, if working in a constant current state for a long time, the conduction loss (Irms 2 times Rds_on) generated by the synchronous rectifying tube is sharply increased, finally, can fail because of the temperature rise, in order to solve this problem, in order to solve the constant current mode, we need to make the power carry out periodic hiccup protection, how to judge that the power works in a constant current state, how to carry out accurate hiccup time protection under the constant current state, the problem that needs to be solved, the industry is mostly that the current is greater than a specific value when entering a certain value through detection, the constant current state, and then the timer is considered to start to be periodically clocked.
The traditional mode has the defects that the hiccup protection condition is frequently generated in the constant voltage working mode due to errors in current detection, and the traditional simulation timing circuit is relatively complex in circuit, and larger in error caused by parasitic parameters and larger in error caused by timing period.
Disclosure of Invention
The utility model aims to provide a novel constant-current hiccup protection circuit which not only can solve the false triggering problem (the problem existing in the constant-current state is judged by adopting a current sampling value) in a constant-voltage mode, but also can accurately control the hiccup protection period.
In order to solve the above-mentioned purpose, the utility model adopts the following technical scheme:
a constant current hiccup protection circuit, comprising: the device comprises an operational amplifier U1, a comparator U2, a controller U3, a resistor R1, a resistor R3, a resistor R4, a resistor R5 and a capacitor C1, wherein the positive input end of the operational amplifier U1 is connected with a reference voltage Iref, the negative input end of the operational amplifier U1 is connected with a sampling voltage Isense of output current and one end of the resistor R1, the other end of the resistor R1 is connected with one end of the resistor R3 and the other end of the capacitor C1, the other end of the resistor R3 is connected with one end of the resistor R4 and the positive input end of the comparator U2, the other end of the resistor R4 is connected with a secondary side ground signal AGND, the negative input end of the comparator U2 is connected with a reference voltage +3.3V, one end of the comparator U2 is connected with a time_out pin of the controller U3, the other end of the resistor R5 is connected with a reference voltage +3.3V, the pin of the controller U3 is connected with a reference voltage +3V, the ND pin of the controller U3 is connected with a secondary side ground signal AGND pin of the controller U3, and the ND pin of the controller U3 is connected with an enable ND pin of the controller.
Preferably, the constant current hiccup protection circuit further includes: the circuit comprises an optocoupler OP1, a resistor R2 and a diode D1, wherein the 1 pin of the optocoupler OP1 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with a power supply VCC, the 2 pin of the optocoupler OP1 is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the output end of an operational amplifier U1, the 3 pin of the optocoupler OP1 is connected with a primary side SGND, and the 4 pin of the optocoupler OP1 is connected with a loop compensation pin FB of a power controller.
Preferably, the controller U3 is of the type GD32F350C8T6.
The circuit is simple, the cost is low, the accurate control hiccup protection period can be ensured under the constant current state, the sampling voltage Isense is larger than the reference voltage Iref under the constant current state, the output signal level of the operational amplifier U1 is low, the voltage of an I_LOOP signal is low, the voltage signal V_LOOP divided by the resistors R3 and R4 is low, when the voltage of the V_LOOP is smaller than the reference voltage +3.3V, the output signal of the comparator U2 is low, the time_out pin of the controller U3 is low, when the time_out pin of the controller U3 is low, the LLC of the controller U3 starts timing, when the specified timing period T1 is reached, the output of the LLC_EN pin of the controller U3 is changed from low level to high level, the power controller stops working, after the output of the power controller U3 is powered down, the timer is restarted, when the voltage of the V_LOOP is smaller than the reference voltage +3.3V, the output of the LLC_out pin of the controller U3 is restored to low level, and when the LLC_EN pin of the controller U3 is reset, and the power controller is reset to be in the state when the specified timing period T1 is reached, and the constant current control is still executed.
The constant-current hiccup protection circuit provided by the utility model can accurately control the hiccup protection period of output through the timer of the controller when the power supply works in a constant-current state, and prevent the failure of the recuperative rectifying MOS tube due to heat accumulation when the power supply works in the constant-current state for a long time.
Drawings
FIG. 1 is a schematic diagram of a constant current hiccup protection circuit of the present utility model;
fig. 2 is a timing control diagram of the constant current hiccup protection circuit of the present utility model.
Detailed Description
The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.
As shown in fig. 1, a schematic diagram of an embodiment of the present utility model includes an operational amplifier U1, a comparator U2, a controller U3, an optocoupler OP1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a diode D1 and a capacitor C1, wherein a positive input terminal of the operational amplifier U1 is connected to a reference voltage Iref, a negative input terminal of the operational amplifier U1 is connected to a sampling voltage Isense of an output current and one end of the resistor R1, the other end of the resistor R1 is connected to one end of the operational amplifier U1 and the other end of the capacitor C1, the other end of the resistor R3 is connected to one end of the resistor R3 and the positive input terminal of the comparator U2, the other end of the resistor R4 is connected to a secondary side ground signal AGND, a negative input terminal of the comparator U2 is connected to a reference voltage +3.3v, one end of the output terminal of the comparator U2 is connected to one end of the resistor R5 and a time_out pin of the controller U3, the other end of the resistor R5 is connected to a reference voltage +3.3v, the other end of the controller U3V pin is connected to a pin of the resistor V3 and the other end of the resistor U3 is connected to the secondary side ground pin of the resistor U1, the diode is connected to the diode b 1, the other end of the resistor R1 is connected to the secondary side ground signal end of the resistor R1 is connected to the resistor R1, and the other end of the resistor 2 is connected to the diode b 1. The model of the controller U3 is a singlechip GD32F350C8T6 capable of accurately controlling the hiccup period.
As shown in fig. 2, in the constant current state, the sampling voltage Isense is greater than the reference voltage Iref, the output signal level of the operational amplifier U1 becomes low, the voltage of the i_loop signal becomes low, the voltage signal v_loop of the i_loop divided by the resistors R3 and R4 becomes low, when the voltage of the v_loop is less than the reference voltage +3.3v, the output signal of the comparator U2 becomes low, the time_out pin of the controller U3 becomes low, when the time_out pin of the controller U3 becomes low, the timer of the controller U3 starts to count, when the specified timing period T1 is reached, the output of the llc_en pin of the controller U3 becomes high, the power controller stops working, the timer of the controller U3 resumes to count after the output is turned off, when the specified timing period T2 is reached, the llc_en pin of the controller U3 resumes to output low, and if the output is still in the constant current state, the control logic cycle is executed.
The conventional constant-current hiccup protection circuit adopts a traditional RC timer, and can not accurately control the interval period due to the error of a resistor and a capacitor.
Claims (3)
1. A constant current hiccup protection circuit, comprising: the device comprises an operational amplifier U1, a comparator U2, a controller U3, a resistor R1, a resistor R3, a resistor R4, a resistor R5 and a capacitor C1, wherein the positive input end of the operational amplifier U1 is connected with a reference voltage Iref, the negative input end of the operational amplifier U1 is connected with a sampling voltage Isense of output current and one end of the resistor R1, the other end of the resistor R1 is connected with one end of the resistor R3 and the other end of the capacitor C1, the other end of the resistor R3 is connected with one end of the resistor R4 and the positive input end of the comparator U2, the other end of the resistor R4 is connected with a secondary side ground signal AGND, the negative input end of the comparator U2 is connected with a reference voltage +3.3V, one end of the comparator U2 is connected with a time_out pin of the controller U3, the other end of the resistor R5 is connected with a reference voltage +3.3V, the pin of the controller U3 is connected with a reference voltage +3V, the ND pin of the controller U3 is connected with a secondary side ground signal AGND pin of the controller U3, and the ND pin of the controller U3 is connected with an enable ND pin of the controller.
2. The constant current hiccup protection circuit of claim 1, further comprising: the circuit comprises an optocoupler OP1, a resistor R2 and a diode D1, wherein the 1 pin of the optocoupler OP1 is connected with one end of the resistor R2, the other end of the resistor R2 is connected with a power supply VCC, the 2 pin of the optocoupler OP1 is connected with the anode of the diode D1, the cathode of the diode D1 is connected with the output end of an operational amplifier U1, the 3 pin of the optocoupler OP1 is connected with a primary side SGND, and the 4 pin of the optocoupler OP1 is connected with a loop compensation pin FB of a power controller.
3. The constant current hiccup protection circuit of claim 1, wherein the controller U3 is model GD32F350C8T6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222818977.7U CN219107288U (en) | 2022-10-25 | 2022-10-25 | Constant current hiccup protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222818977.7U CN219107288U (en) | 2022-10-25 | 2022-10-25 | Constant current hiccup protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219107288U true CN219107288U (en) | 2023-05-30 |
Family
ID=86466445
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222818977.7U Active CN219107288U (en) | 2022-10-25 | 2022-10-25 | Constant current hiccup protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219107288U (en) |
-
2022
- 2022-10-25 CN CN202222818977.7U patent/CN219107288U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9529418B2 (en) | Power supply control device, power supply system and electronic device | |
| CN103312176B (en) | There is the isolated flyback converter of the park mode for light load operation | |
| US7116564B2 (en) | Switching power supply unit and semiconductor device for switching power supply | |
| CN101594048B (en) | PWM buck convertor with overcurrent protection function | |
| CN103746566A (en) | Primary side controlled switching power supply and control method thereof | |
| CN103580486A (en) | Switching power converter dynamic load detection | |
| US20140362609A1 (en) | Power supply device | |
| CN107197571B (en) | BUCK type LED driving circuit capable of preventing power-down back flash | |
| WO2024087637A1 (en) | Switching power source, dcm-based self-powered circuit, and ccm-based self-powered circuit | |
| US20100124080A1 (en) | Current control method and apparatus | |
| CN219107288U (en) | Constant current hiccup protection circuit | |
| WO2023246506A1 (en) | Starting control circuit and switching power source system | |
| CN105141137A (en) | Control circuit used for switch power supply converter | |
| CN205123590U (en) | A control circuit for switching power supply converter | |
| CN216390802U (en) | Switching power supply circuit of ammeter | |
| CN108963999B (en) | Surge current suppressor | |
| US20230299607A1 (en) | Self-powered power supply drive circuit and chip | |
| CN112290512B (en) | Switch power supply overcurrent protection circuit capable of preventing false triggering | |
| CN100389535C (en) | Synchronous rectification switching power supply | |
| CN212380934U (en) | Overheat protection control circuit for power supply | |
| CN211506286U (en) | Auxiliary power supply circuit with wide input voltage range | |
| CN108988297B (en) | Hiccup time control circuit and switching power supply comprising same | |
| CN210898926U (en) | Switching power supply output load discharge circuit | |
| CN211351695U (en) | Output overcurrent protection circuit of high accuracy secondary control | |
| CN200987065Y (en) | Overcurrent protection circuit for power supply apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |