CN2824466Y - Level converting matching circuit and TV set with same - Google Patents
Level converting matching circuit and TV set with same Download PDFInfo
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- CN2824466Y CN2824466Y CNU2005200883059U CN200520088305U CN2824466Y CN 2824466 Y CN2824466 Y CN 2824466Y CN U2005200883059 U CNU2005200883059 U CN U2005200883059U CN 200520088305 U CN200520088305 U CN 200520088305U CN 2824466 Y CN2824466 Y CN 2824466Y
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- level conversion
- match circuit
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Abstract
The utility model discloses a level conversion matching circuit and a television set with the level conversion matching circuit, which comprises a high-low level signal input end which can be an FB signal output end of an SCART chip in the television set; the FB signal output end is connected with a control end of a switching element, one end of a strobe end of the switching element is in earth contact; the other end is connected with a direct-current power supply, and connected with an input end of a level conversion chip; an output end of the level conversion chip is connected with an I/O port of a back level MCU chip. The switching element and the level conversion chip are additionally arranged between the SCART chip of the television set and the MCU chip, and thus, the utility model realizes output level conversion of an FB base pin of the SCART chip so as to be matched with the definition of the I/O port of the MCU chip; thereby, the accuracy identification of SCART chip output signals by the MCU chip can be achieved to ensure the working reliability of a complete appliance.
Description
Technical field
The utility model relates to a kind of level shifting circuit, specifically, thereby relates to a kind ofly be applied in the HDTV to realize that level promotes the change-over circuit that the level that makes different chip chambers reaches coupling.
Background technology
Increase along with digital television program, country will carry out television digitization in 2015 comprehensively, domestic part city has begun to pilot now, so just make the use of high-definition television increase gradually, and all include decoding chip basically in these television set inside, the MCU chip, chips such as SCART, because the 3V that needs that these chips have powers, the 5V that needs that has powers, and also there is difference in the input and output I/O mouth of chip to the identification of high-low level, so just produced the unmatched problem of chip chamber level, this just needs a kind of special change-over circuit of design to realize the efficient transformation of chip chamber level, the demand that makes it to mate different chips.
Summary of the invention
There is the unmatched problem of level in the utility model in order to solve between the prior art chips, a kind of novel level conversion match circuit is provided, by adopting simple circuit configuration, realized effective conversion of level, solved the problem of chip chamber level match.
For solving the problems of the technologies described above, the utility model is achieved by the following technical solutions:
A kind of level conversion match circuit and have the television set of described match circuit, comprise the high-low level signal input part, described high-low level signal input part connects the control end of a switch element, the gating end one end ground connection of described switch element, the other end connects DC power supply on the one hand, the input that connects a level transferring chip on the other hand, the output of described level transferring chip connect the I/O mouth of back level chip.
As further qualification to technique scheme, the FB pin that described high-low level signal input part is a SCART chip in the television set, described switch element adopts a NPN type triode to realize, the base stage of described triode connects the FB pin of SCART chip, collector electrode connects described DC power supply on the one hand, the input that connects level transferring chip on the other hand, grounded emitter.
As the further qualification again to technique scheme, the input of described level transferring chip is through a filter capacitor ground connection, and its output connects the I/O mouth of MCU chip.
As the further qualification again to technique scheme, the model of described level transferring chip is 74LVC14, and its supply power voltage is all identical with the power supply voltage of described DC power supply and MCU.
Compared with prior art, advantage of the present utility model and good effect are: the utility model is by setting up phase inverter and the level transferring chip of being made up of triode between the SCART of television set chip and MCU chip, realized conversion to SCART chip FB pin output level, make it to be complementary with the I/O mouth level definition of MCU chip, thereby realized of the accurate identification of MCU chip, guaranteed the reliability of complete machine work the SCART chip signal output.
Description of drawings
Fig. 1 is the concrete circuit connection diagram of level conversion match circuit in the utility model.
Embodiment
Below in conjunction with the drawings and specific embodiments the utility model is done explanation in further detail.
In the development process of tv product; through regular meeting run between the interface, the unmatched problem of level between the chip; in the tv product that exports to Europe at some; the FB pin of SCART chip; the level that is Fast Blanking signal output pin is defined as: 0～0.4V is a low level; 1～3V is a high level; normally used MCUM16C chip then needs 5V direct current supply; and the I/O mouth is defined as: 0～1V is a low level; 4～5V is a high level, has so just had the unmatched problem of chip chamber level.Address this problem, need a kind of special level conversion match circuit of design to realize that the utility model just provides a kind of like this level conversion match circuit.
Among Fig. 1, to be identification come from the SCART chip from the FB signal of the Pin16 pin of SCART chip output is RGB pattern or CVBS pattern, if the FB signal is a low level, what then select is the CVBS pattern; If the FB signal is a high level, what then select is the RGB pattern, now respectively circuit of the present utility model is analyzed with regard to two kinds of situations.
When the FB signal is that low level is promptly during 0～0.4V, NPN type triode Q7 ends, its collector electrode is high level, + 5V DC power supply affacts the input 1A of level transferring chip U15 (its model is 74LVC14) through resistance R 159, R161, after its conversion, export the I/O mouth of 0V to the MCU chip by its output 1Y, then MCU judges that the FB signal is a low level, thereby switches to corresponding C VBS pattern.When the FB signal is a high level promptly during 1～3V, NPN type triode Q7 conducting, because its grounded emitter, so its collector electrode level is dragged down.Because its collector electrode is connected to the input 1A of level transferring chip U15 through resistance R 161, so what level transferring chip U15 received is low imput, convert thereof into the high level signal of pact+5V, output to the I/O mouth of MCU chip by its output 1Y, then MCU judges that the FB signal is a high level, thereby switches to corresponding RGB pattern.Realized that thus the SCART chip is to the level conversion between the MCU chip.
In the circuit in order to satisfy the I/O mouth requirement of MCU chip, the feeder ear VCC employing+5V direct current supply of level transferring chip U15, on the feeder ear VCC of level transferring chip U15 and input 1A, be connected with filter capacitor C225, C224 respectively, effectively filter out power is made an uproar ripple to the influence of level transferring chip U15, guarantees the accuracy and the stability of circuit working.
The utility model has solved the problem of chip chamber level match by adopting above-mentioned simple circuit configuration, not only can be widely used in equally also extending in the unmatched circuit design of any level in the HDTV (High-Definition Television) product, has wide application.Certainly; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example, and variation, remodeling, interpolation or replacement that those skilled in the art are made in essential scope of the present utility model also should belong to protection range of the present utility model.
Claims (10)
1. level conversion match circuit, comprise the high-low level signal input part, it is characterized in that: described high-low level signal input part connects the control end of a switch element, the gating end one end ground connection of described switch element, the other end connects DC power supply on the one hand, the input that connects a level transferring chip on the other hand, the output of described level transferring chip connect the I/O mouth of back level chip.
2. level conversion match circuit according to claim 1, it is characterized in that: described switch element adopts a NPN type triode to realize, the base stage of described triode connects described high-low level signal input part, collector electrode connects described DC power supply on the one hand, the input that connects level transferring chip on the other hand, grounded emitter.
3. level conversion match circuit according to claim 2 is characterized in that: the input of described level transferring chip is through a filter capacitor ground connection.
4. level conversion match circuit according to claim 1 and 2 is characterized in that: the model of described level transferring chip is 74LVC14A.
5. television set with described level conversion match circuit, comprise the high-low level signal input part, it is characterized in that: described high-low level signal input part connects the control end of a switch element, the gating end one end ground connection of described switch element, the other end connects DC power supply on the one hand, the input that connects a level transferring chip on the other hand, the output of described level transferring chip connect the I/O mouth of back level chip.
6. the television set with described level conversion match circuit according to claim 5, it is characterized in that: described switch element adopts a NPN type triode to realize, the base stage of described triode connects described high-low level signal input part, collector electrode connects described DC power supply on the one hand, the input that connects level transferring chip on the other hand, grounded emitter.
7. the television set with described level conversion match circuit according to claim 6 is characterized in that: the FB pin that described high-low level signal input part is a SCART chip in the television set.
8. the television set with described level conversion match circuit according to claim 7 is characterized in that: the input of described level transferring chip is through a filter capacitor ground connection, and its output connects the I/O mouth of MCU chip.
9. the television set with described level conversion match circuit according to claim 8 is characterized in that: the voltage of described DC power supply is identical with the power supply voltage of MCU.
10. according to each described television set with described level conversion match circuit in the claim 5 to 9, it is characterized in that: the model of described level transferring chip is 74LVC14, and its supply power voltage is identical with the power supply voltage of described MCU.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2005200883059U CN2824466Y (en) | 2005-10-19 | 2005-10-19 | Level converting matching circuit and TV set with same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2005200883059U CN2824466Y (en) | 2005-10-19 | 2005-10-19 | Level converting matching circuit and TV set with same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2824466Y true CN2824466Y (en) | 2006-10-04 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2005200883059U Expired - Fee Related CN2824466Y (en) | 2005-10-19 | 2005-10-19 | Level converting matching circuit and TV set with same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2824466Y (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959003B (en) * | 2009-07-16 | 2012-08-22 | 深圳市九洲电器有限公司 | SCART function selection switching control signal processing circuit and method |
| CN110401490A (en) * | 2019-08-02 | 2019-11-01 | 东莞铭普光磁股份有限公司 | Support the level shifting circuit and level conversion method of MDIO communication |
-
2005
- 2005-10-19 CN CNU2005200883059U patent/CN2824466Y/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101959003B (en) * | 2009-07-16 | 2012-08-22 | 深圳市九洲电器有限公司 | SCART function selection switching control signal processing circuit and method |
| CN110401490A (en) * | 2019-08-02 | 2019-11-01 | 东莞铭普光磁股份有限公司 | Support the level shifting circuit and level conversion method of MDIO communication |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |