CN105811945B - A kind of adaptive switched circuit of car-mounted terminal downloading mode - Google Patents
A kind of adaptive switched circuit of car-mounted terminal downloading mode Download PDFInfo
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- CN105811945B CN105811945B CN201410834567.9A CN201410834567A CN105811945B CN 105811945 B CN105811945 B CN 105811945B CN 201410834567 A CN201410834567 A CN 201410834567A CN 105811945 B CN105811945 B CN 105811945B
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Abstract
It the invention discloses a kind of adaptive switched circuit of car-mounted terminal downloading mode, is connected between the downloading pin of equipment power supply, download interface and car-mounted terminal chip, including metal-oxide-semiconductor, triode, first resistor, second resistance, 3rd resistor and the 4th resistance；The equipment power supply is connected by transforming circuit with the download interface power supply；Equipment power supply is connected to the grid of metal-oxide-semiconductor by first resistor, and download interface power supply is connected with the source electrode of metal-oxide-semiconductor, and the drain electrode of metal-oxide-semiconductor is grounded by second resistance and 3rd resistor；The concatenation point of second resistance and 3rd resistor is connected with the base stage of triode, and download interface power supply is connected by the 4th resistance with the collector of triode, the emitter ground connection of triode；The downloading pin of car-mounted terminal chip is connected with the collector of triode.The circuit structure, instead of traditional physical method, is simplified the down operation of car-mounted terminal, keeps product simpler practical using the mode of level triggers.
Description
Technical field
The present invention relates to a kind of adaptive switched circuits of car-mounted terminal downloading mode, can pass through incoming level more particularly to one kind
Automatically switch the circuit of downloading mode.
Background technique
Car-mounted terminal needs to be downloaded the switching of mode during using for the first time or online upgrading, pass through by
The downloading pin of car-mounted terminal chip is set to low level, so that the chip of car-mounted terminal chip is entered downloading mode, under then passing through
Carry downloading or upgrading that interface carries out program.The method that the prior art switches downloading mode usually installs additional at downloading pin
The downloading pin of car-mounted terminal chip is set to low level, into downloading by physical method by one toggle switch or jumper cap
Mode.This class formation makes to download or update to operate often be carried out by user oneself, and special technical staff is needed to carry out
Operation, while there is also the failure due to caused by toggle switch or jumper cap aged deterioration, inconvenience is caused to actual use.
Summary of the invention
It is an object of the invention to overcome the deficiency of the prior art, provides a kind of adaptive switched electricity of car-mounted terminal downloading mode
Road, by the level triggers of download interface power supply, under the premise of not needing the operation of other physical methods, so that the downloading of chip
Pin level switching, into downloading mode, operating the downloading of car-mounted terminal with online upgrading becomes more simple and convenient.
The technical solution adopted by the present invention to solve the technical problems is: a kind of adaptive switched electricity of car-mounted terminal downloading mode
Road is connected between the downloading pin of equipment power supply, download interface power supply and car-mounted terminal chip, which includes
Metal-oxide-semiconductor, triode, first resistor, second resistance, 3rd resistor and the 4th resistance；The equipment power supply passes through a transforming circuit
It is connected after decompression with the download interface power supply；The equipment power supply is connected to the grid of metal-oxide-semiconductor by first resistor, and downloading connects
Mouth power supply is connected with the source electrode of metal-oxide-semiconductor, and the drain electrode of metal-oxide-semiconductor is grounded by second resistance and 3rd resistor；Second resistance and
The concatenation point of three resistance is connected with the base stage of triode, and download interface power supply passes through the collector phase of the 4th resistance and triode
Connection, the emitter ground connection of triode；The downloading pin of car-mounted terminal chip is connected with the collector of triode.
It preferably, further include the 5th resistance, the grid of the metal-oxide-semiconductor passes through the 5th resistance eutral grounding.
Preferably, the transforming circuit is DC-DC transforming circuit.
Preferably, the transforming circuit is LDO linear voltage-stabilizing circuit.
Preferably, the metal-oxide-semiconductor is P-channel structure.
Preferably, the triode is NPN structure.
The beneficial effects of the present invention are:
1, equipment power supply is connected by a transforming circuit with download interface power supply, and the gate source voltage of metal-oxide-semiconductor, which is greater than, to be cut
Only threshold voltage, metal-oxide-semiconductor cut-off, then triode ends, and the current potential of download interface power supply is made to be maintained at high level；Work as cut-off equipment
Power supply, after download interface power supply is connected with downloading equipment, the gate source voltage of metal-oxide-semiconductor is negative, and metal-oxide-semiconductor conducting, then triode is led
Logical, the current potential for downloading pin is pulled down ground connection, is held in low level, and flip chip enters downloading mode；Made by using level
For trigger condition, during making device downloads more new procedures, shape is carried out without using physical methods such as toggle switch, jumper cap
State switching, and the adaptive switched of downloading mode can be realized by the switching of power supply, operation is simplified, the simpler reality of product is made
With；
2, it is converted between equipment power supply and download interface power supply by DC-DC transforming circuit, can be used for this circuit
In equipment power supply and the biggish equipment of chip power pressure difference；
3, it is converted between equipment power supply and download interface power supply by LDO linear voltage-stabilizing circuit, this circuit is enable to be used
In equipment power supply and the lesser equipment of chip power pressure difference.
Invention is further described in detail with reference to the accompanying drawings and embodiments；But under a kind of car-mounted terminal of the invention
The adaptive switched circuit of load mode is not limited to the embodiment.
Detailed description of the invention
Fig. 1 is circuit diagram of the invention.
Specific embodiment
Embodiment
A kind of adaptive switched circuit of car-mounted terminal downloading mode shown in Figure 1, of the invention, is to be connected to equipment power supply
Between the downloading pin DOWNLOAD of VDD, download interface power supply VCC and car-mounted terminal chip, which includes metal-oxide-semiconductor
Q1, triode Q2, first resistor R1, second resistance R2,3rd resistor R3 and the 4th resistance R4；The equipment power vd D passes through
It is connected after the decompression of one transforming circuit with the download interface power supply VCC；The equipment power vd D is connected to by first resistor R1
The grid of metal-oxide-semiconductor Q1, download interface power supply VCC are connected with the source electrode of metal-oxide-semiconductor Q1, and the drain electrode of metal-oxide-semiconductor Q1 passes through second resistance
R2 and 3rd resistor R3 ground connection；The concatenation point of second resistance R2 and 3rd resistor R3 is connected with the base stage of triode Q2, downloading
Interface power VCC is connected by the 4th resistance R4 with the collector of triode Q2, the emitter ground connection of triode Q2；Vehicle-mounted end
The downloading pin DOWNLOAD of end chip is connected with the collector of triode Q2.
It preferably, further include the 5th resistance R5, the grid of the metal-oxide-semiconductor Q1 is grounded by the 5th resistance R5.
Preferably, the transforming circuit is DC-DC transforming circuit；DC-DC transforming circuit connects for equipment power supply with downloading
The larger situation of mouth power supply pressure difference.
Preferably, the transforming circuit is LDO linear voltage-stabilizing circuit；LDO linear voltage-stabilizing circuit is for equipment power supply under
Carry the lesser situation of interface power pressure difference.
Preferably, the metal-oxide-semiconductor Q1 is P-channel structure.
Preferably, the triode Q2 is NPN structure.
Metal-oxide-semiconductor Q1 uses the P-channel metal-oxide-semiconductor of model AO3401 in the present embodiment, and triode Q2 uses model
The NPN triode of BC817-25, first resistor R1 use resistance value for the resistance of 2K Ω, and second resistance R2 uses resistance value for 100K Ω
Resistance, 3rd resistor R3 uses resistance value for the resistance of 100K Ω, and the 4th resistance R4 uses resistance value for the resistance of 10K Ω, the 5th
Resistance R5 uses resistance value for the resistance of 100K Ω
The course of work of the invention is as follows:
When equipment power vd D accesses circuit, download interface power supply VCC is obtained by equipment power vd D by transforming circuit,
Gate source voltage V simultaneouslygsMore than blanking voltage Vth, end metal-oxide-semiconductor Q1, metal-oxide-semiconductor drain potential is pulled down to place current potential, three poles
The decline of pipe Q2 base potential, triode Q2 cut-off, the collector potential of triode Q2 are pulled to the electricity of download interface power supply VCC
Position, i.e. the downloading pin DOWNLOAD of car-mounted terminal chip are set to high level.
When equipment power vd D and download interface power supply VCC access circuit simultaneously, since equipment power vd D is through transformation electricity
The current potential of current potential obtained and download interface power supply VCC maintain an equal level after the conversion of road, therefore the break-make situation of metal-oxide-semiconductor Q1 and triode Q2
It will not change, the downloading pin DOWNLOAD of car-mounted terminal chip still keeps as high level.
When equipment power vd D does not access circuit and download interface power supply VCC access circuit, equipment power vd D disconnects floating
Sky, the grid potential of metal-oxide-semiconductor Q1 are pulled down to place current potential, and the source electrode of metal-oxide-semiconductor Q1 accesses the current potential of download interface power supply VCC, i.e.,
VgsThe drain voltage of < 0, metal-oxide-semiconductor Q1 conducting, metal-oxide-semiconductor Q1 rises, and triode Q2 base potential is driven to rise, triode Q2 conducting,
The collector potential of triode Q2 declines, and so that the downloading pin DOWNLOAD of car-mounted terminal chip is set to low level, makes vehicle-mounted end
End chip enters downloading mode.
Above-described embodiment is only used to further illustrate a kind of adaptive switched circuit of car-mounted terminal downloading mode of the invention, but this
Invention be not limited to embodiment, according to the technical essence of the invention it is to the above embodiments it is any it is simple modification,
Equivalent variations and modification, fall within the scope of protection of technical solution of the present invention.
Claims (4)
1. a kind of adaptive switched circuit of car-mounted terminal downloading mode is to be connected to equipment power supply, download interface power supply and car-mounted terminal
Between the downloading pin of chip, the adaptive switched circuit include metal-oxide-semiconductor, triode, first resistor, second resistance, 3rd resistor and
4th resistance；The equipment power supply is connected after being depressured by a transforming circuit with the download interface power supply；The equipment electricity
Source is connected to the grid of metal-oxide-semiconductor by first resistor, and download interface power supply is connected with the source electrode of metal-oxide-semiconductor, and the drain electrode of metal-oxide-semiconductor passes through
Second resistance and 3rd resistor ground connection；The concatenation point of second resistance and 3rd resistor is connected with the base stage of triode, and downloading connects
Mouth power supply is connected by the 4th resistance with the collector of triode, the emitter ground connection of triode；Under car-mounted terminal chip
Pin is carried to be connected with the collector of triode；The metal-oxide-semiconductor is P-channel structure；The triode is NPN structure.
2. a kind of adaptive switched circuit of car-mounted terminal downloading mode according to claim 1, it is characterised in that: further include the 5th
The grid of resistance, the metal-oxide-semiconductor passes through the 5th resistance eutral grounding.
3. a kind of adaptive switched circuit of car-mounted terminal downloading mode according to claim 1, it is characterised in that: the transformation electricity
Road is DC-DC transforming circuit.
4. a kind of adaptive switched circuit of car-mounted terminal downloading mode according to claim 1, it is characterised in that: the transformation electricity
Road is LDO linear voltage-stabilizing circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410834567.9A CN105811945B (en) | 2014-12-29 | 2014-12-29 | A kind of adaptive switched circuit of car-mounted terminal downloading mode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410834567.9A CN105811945B (en) | 2014-12-29 | 2014-12-29 | A kind of adaptive switched circuit of car-mounted terminal downloading mode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105811945A CN105811945A (en) | 2016-07-27 |
| CN105811945B true CN105811945B (en) | 2019-04-09 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410834567.9A Active CN105811945B (en) | 2014-12-29 | 2014-12-29 | A kind of adaptive switched circuit of car-mounted terminal downloading mode |
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| CN (1) | CN105811945B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110908689B (en) * | 2019-11-27 | 2023-09-15 | 杭州莱宸科技有限公司 | Program upgrade interface circuit, embedded device, download interface circuit, and downloader |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101751369A (en) * | 2010-01-19 | 2010-06-23 | 深圳市普博科技有限公司 | Online software updating and resetting control circuit and system thereof |
| CN203350646U (en) * | 2013-07-01 | 2013-12-18 | 昆明理工大学 | Automatic downloading device of single-chip microcomputer |
-
2014
- 2014-12-29 CN CN201410834567.9A patent/CN105811945B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101751369A (en) * | 2010-01-19 | 2010-06-23 | 深圳市普博科技有限公司 | Online software updating and resetting control circuit and system thereof |
| CN203350646U (en) * | 2013-07-01 | 2013-12-18 | 昆明理工大学 | Automatic downloading device of single-chip microcomputer |
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| Publication number | Publication date |
|---|---|
| CN105811945A (en) | 2016-07-27 |
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