CN204290265U - A kind of feed protection circuit - Google Patents
A kind of feed protection circuit Download PDFInfo
- Publication number
- CN204290265U CN204290265U CN201420738265.7U CN201420738265U CN204290265U CN 204290265 U CN204290265 U CN 204290265U CN 201420738265 U CN201420738265 U CN 201420738265U CN 204290265 U CN204290265 U CN 204290265U
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- max4788
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- electric capacity
- feed
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Abstract
The utility model discloses a kind of feed protection circuit, comprise MAX4788 chip, electric capacity C156, electric capacity C157, wherein MAX4788 chip pin 1 is output, is connected with low noise output, for low noise provides feed; Play filtering to be connected with MAX4788 chip pin 1 output with electric capacity C156 one end of stabilization, other end ground connection; Chip ground pin two ground connection; Chip pin 3 is Enable Pin, is connected with positive source; MAX4788 chip pin 4 is power feed inputs, is connected with positive source, plays filtering and is connected with positive source with electric capacity C157 one end of stabilization, other end ground connection.The utility model has fault masking time and automatic retray function, can reduce system power dissipation, reduces device failure risk.
Description
Technical field
The utility model relates to a kind of feed protection circuit, belongs to communication equipment field.
Background technology
A lot of receiver need be connected with source antenna Received signal strength now, and receiver need to active antenna feed.Microwave circuit feed generally carries out impedance matching by inductance, feedthrough direct current supply.
In product test and use procedure, active antenna and stube cable likely make the short circuit of feed both positive and negative polarity, cause receiver feed circuit to burn, make complete machine cisco unity malfunction.The current-limiting protection circuit in the past applied, when short trouble, inside still keeps connecting, and still keep a larger current, one is the increase in system power dissipation, and two is that device inside temperature rises, and there is the risk of device failure.
Utility model content
Technical problem to be solved in the utility model is: for overcoming the deficiencies in the prior art, provides a kind of feed protection circuit.
Technical solution of the present utility model is:
A kind of feed protection circuit, comprise MAX4788 chip, electric capacity C156, electric capacity C157, wherein MAX4788 chip pin 1 is output, is connected with low noise output, for low noise provides feed; Play filtering to be connected with MAX4788 chip pin 1 output with electric capacity C156 one end of stabilization, other end ground connection; Chip ground pin two ground connection; Chip pin 3 is Enable Pin, is connected with positive source; MAX4788 chip pin 4 is power feed inputs, is connected with positive source, plays filtering and is connected with positive source with electric capacity C157 one end of stabilization, other end ground connection.
The utility model advantage is compared with prior art:
The utility model has fault masking time and automatic retray function, can reduce system power dissipation, reduces device failure risk.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model.
Embodiment
As shown in Figure 1, a kind of feed protection circuit, comprises MAX4788 chip, electric capacity C156, electric capacity C157, and wherein MAX4788 chip pin 1 is output, is connected with low noise output, for low noise provides feed; Play filtering to be connected with MAX4788 chip pin 1 output with electric capacity C156 one end of stabilization, other end ground connection; Chip ground pin two ground connection; Chip pin 3 is Enable Pin, is connected with positive source; MAX4788 chip pin 4 is power feed inputs, is connected with positive source, plays filtering and is connected with positive source with electric capacity C157 one end of stabilization, other end ground connection.
Power supply enters MAX4788 chip by feed input, and electric capacity C157 is input power filtering, and electric capacity C156 is output current filtering.3 pin of chip MAX4788 are switch closure signals input, and high level makes pass close.
Under normal circumstances, electric current flows into from 4 pin of chip MAX4788, and internal resistance is 0.7 ohm, and the size of threshold current is 100mA.Once the duration that load current exceedes threshold is greater than the fault masking time, switch just disconnects.Owing to having automatic retray function, after the internal retry time, incite somebody to action Closing Switch again; After the shielding time, if load faulty still exists, switch will disconnect again, so go round and begin again, once overload disappears, switch will keep on-state.
The current-limiting protection circuit applied than ever mutually, due to when short trouble, still keeps a larger current (as hundreds of mA); if keep this electric current for a long time; one is the increase in system power dissipation, and two is that device inside temperature rises, and there is the risk of device failure.Chip MAX4788 then thoroughly turns off, and electric current only has 8uA, greatly reduces power consumption and eliminates device failure risk.
Chip MAX4788 is encapsulated as miniature SC70, saves space greatly, and the protective circuit volume applied than ever has had larger reduction, is more suitable for miniaturized receiver.
The unexposed technology of the utility model belongs to general knowledge as well known to those skilled in the art.
Claims (1)
1. a feed protection circuit, is characterized in that, comprises MAX4788 chip, electric capacity C156, electric capacity C157, and wherein MAX4788 chip pin 1 is output, is connected with low noise output, for low noise provides feed; Play filtering to be connected with MAX4788 chip pin 1 output with electric capacity C156 one end of stabilization, other end ground connection; Chip ground pin two ground connection; Chip pin 3 is Enable Pin, is connected with positive source; MAX4788 chip pin 4 is power feed inputs, is connected with positive source, plays filtering and is connected with positive source with electric capacity C157 one end of stabilization, other end ground connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420738265.7U CN204290265U (en) | 2014-11-28 | 2014-11-28 | A kind of feed protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420738265.7U CN204290265U (en) | 2014-11-28 | 2014-11-28 | A kind of feed protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204290265U true CN204290265U (en) | 2015-04-22 |
Family
ID=52873395
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201420738265.7U Active CN204290265U (en) | 2014-11-28 | 2014-11-28 | A kind of feed protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204290265U (en) |
-
2014
- 2014-11-28 CN CN201420738265.7U patent/CN204290265U/en active Active
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |