CN113541479A - Line loss compensation circuit - Google Patents
Line loss compensation circuit Download PDFInfo
- Publication number
- CN113541479A CN113541479A CN202110756719.8A CN202110756719A CN113541479A CN 113541479 A CN113541479 A CN 113541479A CN 202110756719 A CN202110756719 A CN 202110756719A CN 113541479 A CN113541479 A CN 113541479A
- Authority
- CN
- China
- Prior art keywords
- voltage
- resistor
- circuit
- output
- power supply
- 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.)
- Withdrawn
Links
- 238000005070 sampling Methods 0.000 claims abstract description 36
- 230000003321 amplification Effects 0.000 claims description 3
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 238000002955 isolation Methods 0.000 description 5
- 230000003287 optical effect Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000006467 substitution reaction Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of DC power input into DC power output
- H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
- H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
- H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Amplifiers (AREA)
Abstract
本发明公开了一种线损补偿电路，应用于开关电源，其特征在于，包括：采样放大电路、分压电路和加法电路，所述的采样放大电路，用于输入反应开关电源输出情况的采样电压V1，并进行放大后输出电压V2；所述的分压电路，用于对所述的电压V2进行分压，输出分压电压V3；所述的加法电路，用于将所述的分压电压V3与基准电压VREF进行加法运算后输出电压Vf，所述的电压Vf被作为开关电源电压环路的基准电压。本发明的方法及电路，可解决开关电源输出线损过长、输出线过长导致输出电压下降或者变化过大等情况下线损补偿功能。具有电路结构简易、主动调节，适用不同线损环境下，成本较低的特点。
The invention discloses a line loss compensation circuit, which is applied to a switching power supply, and is characterized in that it includes a sampling amplifying circuit, a voltage dividing circuit and an adding circuit, and the sampling amplifying circuit is used for inputting a sampling reflecting the output condition of the switching power supply. voltage V1, and output voltage V2 after amplifying; the voltage divider circuit is used to divide the voltage V2 to output the divided voltage V3; the addition circuit is used to divide the voltage After adding the voltage V3 and the reference voltage VREF, a voltage Vf is output, and the voltage Vf is used as the reference voltage of the switching power supply voltage loop. The method and circuit of the present invention can solve the line loss compensation function in the case that the output line loss of the switching power supply is too long, the output voltage is too long, and the output voltage drops or changes too much. It has the characteristics of simple circuit structure, active adjustment, suitable for different line loss environments, and low cost.
Description
Technical Field
The invention belongs to the technical field of switching power supplies, and particularly relates to line loss compensation of output voltage of a switching power supply.
Background
According to a relational expression V-R-I of the voltage V, the resistor R and the current I, the impedance of a connecting line from the output end of the switching power supply to equipment and the output current of the switching power supply can cause the voltage from the output voltage to the equipment to change, the power supply voltage deviation on the equipment can often cause the instability of the equipment, therefore, the output voltage precision is an important index in the performance of the switching power supply, and most of switching power supplies with high power or longer output lines have a line loss compensation function. However, the existing line loss compensation control mode, device composition, cost, structure and performance have no advantages. The prior art mainly has the following characteristics:
the current commonly used line loss compensation circuit widely adopts a circuit scheme that two lines are connected to the output end of a switching power supply to sample the voltage of equipment, and the scheme needs an external wire to cause high cost on one hand, and leads to complex wiring on the other hand, thus causing waste of space and cost.
In addition, a delay protection circuit built by adopting an analog device is also available, but active adjustment cannot be realized due to different line losses, and the application range is narrow.
Disclosure of Invention
Therefore, the present invention is to provide a line loss compensation circuit, which reduces the line loss when the connection line from the output terminal of the switching power supply to the device is long or the output current of the switching power supply is large, and has the characteristics of simple circuit structure, active adjustment, suitability for different line loss environments, and low cost.
In order to achieve the purpose, the invention adopts the following technical scheme:
a line loss compensation circuit is applied to a switching power supply and is characterized by comprising: a sampling amplifying circuit and an adding circuit;
the sampling amplifying circuit is used for inputting a sampling voltage V1 reflecting the output condition of the switching power supply and outputting a voltage V2 after amplification;
and the addition circuit is used for adding the voltage V2 and a reference voltage VREF and outputting a voltage Vf, wherein the voltage Vf is used as a reference voltage of the switching power supply voltage loop.
Further, the sampling voltage V1 is a voltage obtained by sampling the output voltage of the switching power supply, or a voltage obtained by sampling the output current of the switching power supply.
As a specific embodiment of the sampling amplification circuit, the following features are provided: the operational amplifier U1B, a resistor R1 and a resistor R2 are included, the non-inverting input end of the operational amplifier U1B is used for inputting a sampling voltage V1, one end of the resistor R1 is grounded, the other end of the resistor R2 is simultaneously connected with the inverting input end of the operational amplifier U1B and one end of the resistor R2, and the output end of the operational amplifier U1B and the other end of the resistor R2 are connected together to output a voltage V2.
Further, the resistor R2 is an adjustable resistor.
Further, the line loss compensation circuit further includes: a voltage dividing circuit;
the voltage dividing circuit is used for dividing the voltage V2 and outputting a divided voltage V3;
and the addition circuit is used for adding the divided voltage V3 and a reference voltage VREF and outputting a voltage Vf, wherein the voltage Vf is used as a reference voltage of a switching power supply voltage loop.
As a specific embodiment of the voltage divider circuit, the following is provided: the voltage divider comprises a resistor R3 and a resistor R4, wherein one end of the resistor R3 is used for inputting a voltage V2, the other end of the resistor R3 is connected with one end of a resistor R4, a divided voltage V3 is output, and the other end of the resistor R4 is grounded.
Further, the sampling amplifying circuit comprises an operational amplifier U1B, a resistor R1 and a resistor RP1, wherein the non-inverting input end of the operational amplifier U1B is used for inputting a sampling voltage V1, one end of the resistor R1 is grounded, the other end of the resistor R2 is simultaneously connected with the inverting input end of the operational amplifier U1B and one end of the resistor R2, and the output end of the operational amplifier U1B is connected with the other end of the resistor R2 to output a voltage V2.
As a specific embodiment of the addition circuit, the addition circuit is characterized in that: the circuit comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8 and an operational amplifier U1A, one end of a resistor R5 is used for inputting a divided voltage V3, the other end of the resistor R5 is simultaneously connected with one end of the resistor R6 and an inverting input end of the operational amplifier U1A, the other end of the resistor R6 is used for inputting a reference voltage VREF, one end of a resistor R7 is simultaneously connected with one end of the resistor R8 and an inverting input end of the operational amplifier U1A, the other end of the resistor R7 is grounded, the other end of the resistor R8 is connected with an output end of the operational amplifier U1A and used for outputting a voltage Vf.
Further, the resistances of the resistor R5, the resistor R6, the resistor R7 and the resistor R8 are the same.
The working principle of the invention is analyzed by combining with a specific embodiment, which is not described herein, and compared with the prior art, the invention has the following beneficial effects:
1. when the loss of the output voltage line is large, the voltage of the equipment end can still keep high voltage precision;
2. the circuit can be used as an overvoltage protection functional circuit of a switching power supply when sampling the output main power voltage, can be used as an overpower protection functional circuit of the switching power supply when sampling the output main power current, and can also be used as an overtemperature protection functional circuit and the like to realize various multiplexing functions of the circuit;
3. when the adjustable resistor is adopted, the adjustable resistor can adapt to different line resistors, and effectively solves the problem of larger output voltage precision deviation caused by different line impedances of the switching power supply;
4. the circuit of the invention does not use a digital control chip, thereby reducing the complexity of the circuit, reducing the development cost and having more advantages in the aspects of space and cost.
Drawings
Fig. 1 is a schematic diagram of a line loss compensation circuit according to a first embodiment of the present invention applied to a switching power supply;
fig. 2 is a schematic diagram of a line loss compensation circuit according to a second embodiment of the present invention applied to a switching power supply;
fig. 3 is a schematic diagram of an application of a line loss compensation circuit according to a third embodiment of the present invention in a switching power supply.
Detailed Description
In order to make the technical scheme of the invention clearer, the following describes an embodiment of the invention clearly and completely with reference to the accompanying drawings. It should be understood that the embodiments described are part of the present invention, and those skilled in the art may make various other changes, substitutions and alterations without making any inventive change to the present invention.
First embodiment
Fig. 1 is a diagram showing a structure of a line loss compensation circuit according to a first embodiment of the present invention, where the line loss compensation circuit includes a sampling amplifier circuit, a voltage divider circuit, and an adder circuit.
The sampling amplifying circuit comprises an operational amplifier U1B, a resistor R1 and an adjustable resistor RP1, wherein the non-inverting input end of the operational amplifier U1B is used for inputting a sampling voltage V1, one end of the resistor R1 is grounded, the other end of the resistor R2 is simultaneously connected with the inverting input end of the operational amplifier U1B and one end of the resistor RP1, the output end of the operational amplifier U1B and the other end of the resistor RP1 are connected together to output a voltage V2, and the relation between the voltage V2 and the sampling voltage V1 is as follows:
wherein R1 is the resistance of resistor R1, and RP1 is the resistance of resistor RP 1.
The voltage division circuit comprises a resistor R3 and a resistor R4, one end of the resistor R3 is used for inputting a voltage V2, the other end of the resistor R3 is connected with one end of the resistor R4 together to output a divided voltage V3, the other end of the resistor R4 is grounded, and the relation between the divided voltage V3 and the voltage V2 is as follows:
wherein R3 is the resistance of the resistor R3, and R4 is the resistance of the resistor R4.
The adding circuit comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8 and an operational amplifier U1A, one end of the resistor R5 is used for inputting a divided voltage V3, the other end of the resistor R5 is simultaneously connected with one end of the resistor R6 and the inverting input end of the operational amplifier U1A, the other end of the resistor R6 is used for inputting a reference voltage VREF, one end of the resistor R7 is simultaneously connected with one end of the resistor R8 and the non-inverting input end of the operational amplifier U1A, the other end of the resistor R7 is grounded, and the other end of the resistor R8 is connected with the output end of the operational amplifier U1A and used for outputting a voltage Vf.
The application scheme of the line loss compensation circuit in the embodiment in the switching power supply is as follows: the sampling voltage V1 input by the line loss compensation circuit is an output voltage sampling signal or an output current sampling signal of the switching power supply, a voltage loop of the switching power supply comprises a resistor R9, a resistor R10, an operational amplifier U1C and an isolation feedback optical coupler OC1, one end of the resistor R9 is simultaneously connected with the output voltage Vo of the switching power supply and an A pin of the isolation feedback optical coupler OC1, the other end of the resistor R9 is simultaneously connected with one end of the resistor R10 and the reverse input end of the operational amplifier U1C, the other end of the resistor R10 is grounded, the same-direction input end of the operational amplifier U1C is connected with the output end of the operational amplifier U1A, the output end of the operational amplifier U1C is connected with a K pin of the isolation feedback optical coupler OC1, a C pin of the isolation feedback optical coupler OC1 is connected with the output voltage feedback signal FB of the switching power supply, and an E pin of the isolation feedback optical coupler OC1 is grounded.
The voltage Vf output by the output end of the operational amplifier U1A is used as the reference voltage of the voltage loop of the switching power supply to adjust the output voltage Vo of the switching power supply, and the working principle is as follows:
for convenience of debugging calculation, the resistances of the resistor R5, the resistor R6, the resistor R7 and the resistor R8 are the same, and a calculation formula of the voltage output by the output end of the operational amplifier U1A is as follows:
formula (3) Vf ═ VREF + V3.
Wherein VREF is the voltage value of the reference voltage;
the calculation formula of the output voltage Vo of the switching power supply is as follows:
the sampling voltage V1 is calculated as:
V1＝IORREF.. equation (5)
Wherein IOIs the output current of the switching power supply, RREFThe resistance value of a sampling resistor for sampling the output current of the switching power supply;
simultaneous equations (1), (2), (3), (4) and (5) can be obtained, and the output voltage equation of the switching power supply is as follows:
from equation (6), the output voltage VO of the switching power supply is composed of two parts, i.e., the line loss voltage
And terminal voltage of equipment
In addition, it can be seen from the formula (6) that the output voltage of the switching power supply is independent of the output current, the power supply voltage obtained on the device can maintain high voltage precision by debugging the resistance RP1 of the adjustable resistor, the resistance RP1 of the adjustable resistor can be debugged once, and after the resistance RP1 of the adjustable resistor is adjusted, the switching power supply can automatically adjust the output voltage regardless of the change of the output current, so that the voltage provided to the device end is always unchanged.
The debugging method of the resistance value RP1 of the adjustable resistor is as follows:
since the line loss voltage is in turn equal to the product of the cable impedance and the output current of the switching power supply, namely:
wherein, DeltaV is the line loss voltage drop from the output end of the switching power supply to the equipment end, RLOSSFor the impedance from the output of the switching power supply to the device, the resistance RP1 of the adjustable resistor is calculated as follows:
it can be seen from formula (8) that RP1 is a fixed value, and RP1 is not affected by the output current and the line impedance, and it can be similarly found that when the line impedance is fixed, RP1 is the fixed value, and the load current of the switching power supply changes, the output voltage is automatically adjusted, so that the voltage at the device end is always kept constant.
Second embodiment
As shown in fig. 2, which is a schematic diagram of an application of a line loss compensation circuit in a switching power supply according to a second embodiment of the present invention, this embodiment is different from the first embodiment in that a voltage divider circuit is omitted, a compensation range can be further enlarged, and when an impedance from a power supply output terminal to a device terminal is large, a compensation amount needs to be increased, and at this time, a voltage V1 output by a sampling amplifier circuit can be directly used as a compensation voltage.
Third embodiment
As shown in fig. 3, which is a schematic diagram of an application of a line loss compensation circuit in a switching power supply according to a third embodiment of the present invention, this embodiment is different from the first embodiment in that an adjustable resistor RP1 is replaced by a resistor R2 with a fixed resistance value. This embodiment is applicable to the fixed condition of line impedance, changes adjustable resistance into fixed resistance, can reduce to respond to mechanical external force to lead to the change of adjustable resistance, increases switching power supply's uniformity, improves switching power supply's compensation accuracy and stability.
Although the present invention has been described in detail by way of examples, those skilled in the art can make modifications and substitutions to the specific embodiments of the present invention without departing from the spirit and scope of the present invention as defined by the appended claims.
Claims (9)
1. A line loss compensation circuit is applied to a switching power supply and is characterized by comprising: a sampling amplifying circuit and an adding circuit;
the sampling amplifying circuit is used for inputting a sampling voltage V1 reflecting the output condition of the switching power supply and outputting a voltage V2 after amplification;
and the addition circuit is used for adding the voltage V2 and a reference voltage VREF and outputting a voltage Vf, wherein the voltage Vf is used as a reference voltage of the switching power supply voltage loop.
2. The line loss compensation circuit of claim 1, wherein: the sampling voltage V1 is a voltage obtained by sampling the output voltage of the switching power supply, or a voltage obtained by sampling the output current of the switching power supply.
3. The line loss compensation circuit of claim 1, wherein: the sampling amplifying circuit comprises an operational amplifier U1B, a resistor R1 and a resistor R2, wherein the non-inverting input end of the operational amplifier U1B is used for inputting sampling voltage V1, one end of the resistor R1 is grounded, the other end of the resistor R2 is simultaneously connected with the inverting input end of the operational amplifier U1B and one end of the resistor R2, and the output end of the operational amplifier U1B is connected with the other end of the resistor R2 to output voltage V2.
4. The line loss compensation circuit of claim 4, wherein: the resistor R2 is an adjustable resistor.
5. The line loss compensation circuit of claim 1, further comprising: a voltage dividing circuit;
the voltage dividing circuit is used for dividing the voltage V2 and outputting a divided voltage V3;
and the addition circuit is used for adding the divided voltage V3 and a reference voltage VREF and outputting a voltage Vf, wherein the voltage Vf is used as a reference voltage of a switching power supply voltage loop.
6. The line loss compensation circuit of claim 5, wherein: the voltage division circuit comprises a resistor R3 and a resistor R4, one end of the resistor R3 is used for inputting a voltage V2, the other end of the resistor R3 is connected with one end of the resistor R4 to output a divided voltage V3, and the other end of the resistor R4 is grounded.
7. The line loss compensation circuit of claim 6, wherein:
the sampling amplifying circuit comprises an operational amplifier U1B, a resistor R1 and a resistor RP1, wherein the non-inverting input end of the operational amplifier U1B is used for inputting a sampling voltage V1, one end of the resistor R1 is grounded, the other end of the resistor R2 is simultaneously connected with the inverting input end of the operational amplifier U1B and one end of the resistor R2, and the output end of the operational amplifier U1B is connected with the other end of the resistor R2 to output a voltage V2.
8. The line loss compensation circuit of any one of claims 1 to 7, wherein: the summing circuit comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8 and an operational amplifier U1A, one end of the resistor R5 is used for inputting a divided voltage V3, the other end of the resistor R5 is simultaneously connected with one end of the resistor R6 and the inverting input end of the operational amplifier U1A, the other end of the resistor R6 is used for inputting a reference voltage VREF, one end of the resistor R7 is simultaneously connected with one end of the resistor R8 and the non-inverting input end of the operational amplifier U1A, the other end of the resistor R7 is grounded, and the other end of the resistor R8 and the output end of the operational amplifier U1A are connected together and used for outputting a voltage Vf.
9. The line loss compensation circuit of claim 8, wherein: the resistances of the resistor R5, the resistor R6, the resistor R7 and the resistor R8 are the same.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110756719.8A CN113541479A (en) | 2021-07-05 | 2021-07-05 | Line loss compensation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110756719.8A CN113541479A (en) | 2021-07-05 | 2021-07-05 | Line loss compensation circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113541479A true CN113541479A (en) | 2021-10-22 |
Family
ID=78097747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110756719.8A Withdrawn CN113541479A (en) | 2021-07-05 | 2021-07-05 | Line loss compensation circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113541479A (en) |
-
2021
- 2021-07-05 CN CN202110756719.8A patent/CN113541479A/en not_active Withdrawn
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3756515B2 (en) | Impedance emulator | |
| CN112462838B (en) | Low Dropout Linear Regulator Overcurrent Protection Circuit with Adjustable Overcurrent Limit and Foldback | |
| CN109491440B (en) | Voltage reference circuit | |
| CN102033561B (en) | Power supply circuit | |
| US20090134709A1 (en) | System and method for cable resistance cancellation | |
| CN207488871U (en) | A kind of CMOS low pressure difference linear voltage regulators using novel buffer | |
| CN104122920B (en) | Configurable upper low pressure difference linear voltage regulator | |
| CN108512282B (en) | Power supply circuit, terminal equipment and power supply control method thereof | |
| CN104333221A (en) | Adaptive line loss compensation circuit for DC-DC (direct current) converter | |
| JP2024526280A (en) | Power detection circuit, chip and communication terminal | |
| EP0337444A2 (en) | MOS voltage to current converter | |
| CN118739227B (en) | A closed-loop control surge suppression circuit based on PMOS tube | |
| US4564879A (en) | Electronic power overload protection circuit | |
| CN113541479A (en) | Line loss compensation circuit | |
| CN109036301A (en) | A kind of distal end voltage compensating method compensated automatically based on hardware circuit | |
| CN116243749A (en) | Low-dropout linear voltage regulator and electronic equipment | |
| CN216290682U (en) | Line loss compensation circuit | |
| CN115480611A (en) | Power supply circuit, power supply system and electronic equipment | |
| US4588858A (en) | Differential amplifiers and method of differentially driving a two-wire line circuit | |
| CN111864534A (en) | A semiconductor laser constant current drive circuit | |
| CN116679782A (en) | Low-dropout linear voltage regulator with current limiting protection function, chip and electronic equipment | |
| CN101510724B (en) | Low voltage output circuit | |
| US5050210A (en) | Metallic current limiter | |
| CN107040228A (en) | A kind of failure circuit suitable for dead-band regulator | |
| CN206790449U (en) | A kind of failure circuit suitable for dead-band regulator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20211022 |