CN209168092U - Voltage follower circuit and electronic equipment - Google Patents
Voltage follower circuit and electronic equipment Download PDFInfo
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- CN209168092U CN209168092U CN201920050996.5U CN201920050996U CN209168092U CN 209168092 U CN209168092 U CN 209168092U CN 201920050996 U CN201920050996 U CN 201920050996U CN 209168092 U CN209168092 U CN 209168092U
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Abstract
It includes first input end, the second input terminal, common output end, first switch circuit, second switch circuit and switch switching circuit that the utility model, which discloses a kind of voltage follower circuit and electronic equipment, voltage follower circuit,；The input terminal of the first switch circuit is connected to the first input end, the output end of the first switch circuit is connected to the common output end；The input terminal of the second switch circuit is connected to second input terminal, the output end of the second switch circuit is connected to the common output end；The input terminal of the switch switching circuit is connected to first input end, and two output ends of the switch switching circuit are respectively connected to first switch circuit and the second switch circuit and select a conducting to control the first switch circuit and the second switch circuit；Wherein, the common output end is connected to I2C interface.The technical solution of the utility model has the advantages that improve the compatibility of principal and subordinate's device in I2C system.
Description
Technical field
The utility model relates to electronic technology field more particularly to a kind of voltage follower circuits and electronic equipment.
Background technique
In electronic field, using the chip of I2C agreement using very universal, such as EEPROM (Electrically
Erasable Programmable read only memory, band electric erazable programmable read-write memory), Driver IC (drive
Dynamic integrated circuit), sensor chip etc. connect from device by I2C bus with main device；And for different products, I2C association
Discussing the operating voltage used may be different, such as 1.8V, 2.8V or 3.3V, but I2C protocol requirement is from device end and main device
Part end I2C electrical level match is just able to achieve normal communication, and existing I2C level shift (level shifting circuit) is general only
It is able to achieve a kind of level conversion at another level, when being converted into 1.8V by 3.3V such as level shift restriction, just not
2.8V can be converted to, the poor compatibility for the system for causing principal and subordinate's device to be formed.
Utility model content
The main purpose of the utility model is to provide a kind of voltage follower circuit and electronic equipments, it is intended to solve existing skill
The problem of poor compatibility for the system that master and slave equipment is formed in art.
To achieve the above object, the utility model provides a kind of voltage follower circuit, and voltage follower circuit includes first defeated
Enter end, the second input terminal, common output end, first switch circuit, second switch circuit and switch switching circuit；
The input terminal of the first switch circuit is connected to the output end of the first input end, the first switch circuit
It is connected to the common output end；
The input terminal of the second switch circuit is connected to the output end of second input terminal, the second switch circuit
It is connected to the common output end；
The input terminal of the switch switching circuit is connected to first input end, two output ends of the switch switching circuit
First switch circuit and the second switch circuit are respectively connected to control the first switch circuit and the second switch
Circuit selects a conducting；
Wherein, the common output end is connected to I2C interface.
Preferably, the switch switching circuit includes the first switching circuit and the second switching circuit, wherein
First switching circuit connects the first input end and the first switch circuit；
Second switching circuit connects the first input end and the second switch circuit.
Preferably, first switching circuit includes the first bleeder circuit and the first electronic switch, first electronic cutting
Closing includes three ends, wherein
First electronic switch one end is connected to the first input end through first bleeder circuit；
The first electronic switch other end is connected to the first switch circuit；
First electronic switch further holds ground connection.
Preferably, first switching circuit further includes the first current-limiting resistance R11, the first current-limiting resistance R11 connection
Between first bleeder circuit and the first electronic switch.
Preferably, first bleeder circuit includes the first divider resistance R1 and the second divider resistance R2, wherein
First electronic switch through the first current-limiting resistance R11, that the first divider resistance R1 is connected to described first is defeated
Enter end, meanwhile, first electronic switch is grounded through the first current-limiting resistance R11, the second divider resistance R2.
Preferably, second switching circuit includes the second bleeder circuit and the second electronic switch, second electronic cutting
Closing includes three ends, wherein
Second electronic switch one end is connected to the first input end through second bleeder circuit；
The second electronic switch other end is connected to the second switch circuit；
Second electronic switch further holds ground connection.
Preferably, second switching circuit further includes the second current-limiting resistance R12, the first current-limiting resistance R12 connection
Between second bleeder circuit and the second electronic switch.
Preferably, second bleeder circuit includes third divider resistance R3 and the 4th divider resistance R4, wherein described
Two electronic switches are connected to the first input end through the second current-limiting resistance R11, third divider resistance R3, meanwhile, it is described
Second electronic switch is grounded through the second current-limiting resistance R12, the 4th divider resistance R4.
Preferably, the I2C interface includes main device connecting pin, data signal end, clock signal terminal, the second pull-up resistor
R42 and third pull-up resistor R43, wherein
The main device connecting pin is connected to the first input end；
The data signal end is connected to the common output end through the second pull-up resistor R42；
The clock signal terminal is connected to the common output end through third pull-up resistor R43.
In addition, to achieve the above object, the utility model also provides a kind of electronic equipment, the electronic equipment includes main device
Part and from device, the main device includes first power supply with the first input end, it is described from device include have it is described
The second source of second input terminal, it is described include from device further include the voltage follower circuit stated such as any of the above-described, it is described from
Device is connect through the I2C interface with the main device.
In the technical solution of the utility model, the first switch circuit and described is controlled by the switch switching circuit
Second switch circuit selects a conducting, when the first input end has voltage input, first switch circuit conducting and by institute
Operating voltage of the first voltage as the I2C interface of first input end input is stated, so that main device and between device
Voltage matches realize normal communication, the first voltage of first input end input can there are many, and by the work of the I2C interface
Make voltage high to corresponding first voltage, principal and subordinate's device normal communication can be realized, to improve principal and subordinate's device group composition
I2C system compatibility；In first input end no-voltage input, the power supply carried from device is enabled from described second
Input terminal is to the second switch circuit output voltage, the second switch circuit conducting and by second input terminal input
Operating voltage of the voltage as the I2C interface, guarantee main device and between device being capable of normal communication.
Detailed description of the invention
Fig. 1 is the circuit diagram of the voltage follower circuit first embodiment of the utility model；
Fig. 2 is the circuit diagram of the I2C interface of the utility model；
Fig. 3 is the circuit diagram of the control circuit of the slave device of the utility model.
The embodiments will be further described with reference to the accompanying drawings for the realization, functional characteristics and advantage of the utility model aim.
Specific embodiment
The following will be combined with the drawings in the embodiments of the present invention, carries out the technical scheme in the embodiment of the utility model
Clearly and completely describing, it is clear that described embodiment is only a part of the embodiment of the utility model, rather than all
Embodiment.Based on the embodiments of the present invention, those of ordinary skill in the art are not making creative work premise
Under every other embodiment obtained, fall within the protection scope of the utility model.
It is to be appreciated that the directional instruction (such as up, down, left, right, before and after ...) of institute in the utility model embodiment
It is only used for explaining in relative positional relationship, the motion conditions etc. under a certain particular pose (as shown in the picture) between each component, such as
When the fruit particular pose changes, then directionality instruction also correspondingly changes correspondingly.
In addition, the description for being related to " first ", " second " etc. in the present invention is used for description purposes only, and cannot understand
For its relative importance of indication or suggestion or implicitly indicate the quantity of indicated technical characteristic.Define as a result, " first ",
The feature of " second " can explicitly or implicitly include at least one of the features.In addition, the technical side between each embodiment
Case can be combined with each other, but must be based on can be realized by those of ordinary skill in the art, when the combination of technical solution
Conflicting or cannot achieve when occur will be understood that the combination of this technical solution is not present, also not in the requires of the utility model
Protection scope within.
Referring to Fig. 1, the utility model provides a kind of voltage follower circuit, the voltage follower circuit includes the first input
Hold 1A, the second input terminal 1B, common output end 2, first switch circuit 3, second switch circuit 4 and switch switching circuit 5；
The input terminal of the first switch circuit 3 be connected to the first input end 1A, the first switch circuit 3 it is defeated
Outlet is connected to the common output end 2；
The input terminal of the second switch circuit 4 be connected to the second input terminal 1B, the second switch circuit 4 it is defeated
Outlet is connected to the common output end 2；
The input terminal of the switch switching circuit 5 is connected to first input end 1A, and two of the switch switching circuit 5
Output end is respectively connected to first switch circuit 3 and the second switch circuit 4 to control the first switch circuit 3 and described
Second switch circuit 4 selects a conducting；
Wherein, the common output end 2 is connected to I2C interface (see Fig. 2).
In the present embodiment, the voltage follower circuit is applied to set using the electronic equipment of I2C agreement (bus), electronics
It standby main device and is connected from device by I2C bus, I2C bus is connected to the I2C interface from device, described to pass through from device
I2C interface and the main device, which are realized, to be connected.The first switch circuit 3 and described is controlled by the switch switching circuit 5
Second switch circuit 4 selects a conducting, that is, the second switch circuit 4 is closed when the first switch circuit 3 conducting, when
When the first switch circuit 3 is closed, the second switch circuit 4 is connected.
When the first switch circuit 3 conducting, the second switch circuit 4 is closed, since first switch circuit 3 connects
To the first input end 1A, meanwhile, so that the first input end 1A is connected to the voltage output end of the main device, the master
Device exports first voltage VCC-IN to the first switch circuit 3, and first voltage VCC-IN is through the first switch circuit
3 send the I2C interface to, using the first voltage VCC-IN as the operating voltage of the I2C interface, at this point, being connected to
The operating voltage of the I2C bus of the I2C interface is the first voltage VCC-IN, is connected to the I2C bus at this time
The operating voltage of slave device be the first voltage VCC-IN, namely at this point, the main device and the work electricity from device
Press identical, the main device is communicated with can be normally carried out from device.Specifically, the first voltage VCC-IN can for 1.8V/,
The operating voltage of 2.8V, 3.8V etc., the 2C bus can also accordingly be adjusted to 1.8V/, 2.8V, 3.8V etc..
When the second switch circuit 4 conducting, the first switch circuit 3 is closed, at this point, the first input end 1A
There is no voltage input.Since second switch circuit 4 is connected to the second input terminal 1B, meanwhile, make the second input terminal 1B
It is connected to the voltage output end of the power supply carried from device, it is described to export second from device to the second switch circuit 4
Voltage VDD, second voltage VDD send the I2C interface to through the second switch circuit 4, at this point, if the second voltage
VDD is consistent with the operating voltage of the main device, is such as all 1.8V, then it is described can positive normal open between device and the main device
News；At this point, setting pull-up resistor etc. can be passed through if the operating voltage of the second voltage VDD and the main device are inconsistent
Mode the second voltage VDD is pulled to it is consistent with the operating voltage of the main device, guarantee the main device with from device
Between normal work.Preferably, the second voltage VDD can be set to described from the more commonly used operating voltage of device,
Such as 1.8V, 2.8V, 3.8V.
In the present embodiment, the first switch circuit 3 and the second switch are controlled by the switch switching circuit 5
Circuit 4 selects a conducting, when the first input end 1A has voltage input, the first switch circuit 3 conducting and by described the
Operating voltage of the first voltage VCC-IN as the I2C interface of one input terminal 1A input so that main device with from device it
Between voltage matches realize normal communication, the first voltage VCC-IN of first input end 1A input can there are many, and by institute
The operating voltage for stating I2C interface draws high corresponding first voltage VCC-IN, principal and subordinate's device normal communication can be realized, to mention
The high compatibility of the I2C system of principal and subordinate's device composition；In first input end 1A no-voltage input, enable from device certainly
The power supply of band is from the second input terminal 1B to 4 output voltage of second switch circuit, and the conducting of second switch circuit 4 is simultaneously
Using the second voltage VDD of the second input terminal 1B input as the operating voltage of the I2C interface, guarantee main device with from
Between device being capable of normal communication.
Preferably, the switch switching circuit 5 includes the first switching circuit 51 and the second switching circuit 52, wherein
First switching circuit 51 connects the first input end 1A and the first switch circuit 3；
Second switching circuit 52 connects the first input end 1A and the second switch circuit 4.
In the present embodiment, the first input end 1A is simultaneously to first switching circuit 51, the second switching circuit 52
First voltage VCC-IN is inputted, the first switch circuit 3 is connected in the first voltage VCC-IN, while making described the
Two switching circuits 4 are closed, and send the first voltage VCC-IN to the common output end 2 when first switch circuit 3 is connected,
Using the operating voltage by the first voltage VCC-IN as the I2C interface.
Preferably, first switching circuit 51 includes the first bleeder circuit 511 and the first electronic switch Q1, and described the
One electronic switch Q1 includes three ends, wherein
Described one end first electronic switch Q1 is connected to the first input end 1A through first bleeder circuit 511；
The first electronic switch Q1 other end is connected to the first switch circuit 3；
The first electronic switch Q1 further holds ground connection.
In the present embodiment, the first electronic switch Q1 is triode, and the base stage of the triode is through described first point
Volt circuit 511 is connected to the first input end 1A, and the collector of the triode is connected to the first switch circuit 3, institute
State the emitter ground connection of triode.The first voltage VCC-IN of the first input end 1A input is through first bleeder circuit
The first electronic switch Q1 is driven to open after 511 partial pressures, the first electronic switch Q1 drives the first switch when opening
Circuit 3 is connected, so that the first switch circuit 3 sends the first voltage VCC-IN to the common output end 2,
Using the operating voltage by the first voltage VCC-IN as the 2C interface.
It is understood that the first electronic switch Q1 can be other electronic switching devices such as metal-oxide-semiconductor etc., it is any to pass through
The design that transformation transistor types and quantity reach equifinality should be included in the protection scope of the utility model.
Preferably, first switching circuit 51 further includes the first current-limiting resistance R11, the first current-limiting resistance R11 company
It is connected between first bleeder circuit 511 and the first electronic switch Q1.
In the present embodiment, the first current-limiting resistance R11 is set to the first electronic switch Q1 namely triode
Base stage protects the PN junction of triode not damage because of high current.
Preferably, first bleeder circuit 511 includes the first divider resistance R1 and the second divider resistance R2, wherein institute
It states the first electronic switch Q1 and is connected to the first input end 1A through the first current-limiting resistance R11, the first divider resistance R1,
Meanwhile the first electronic switch Q1 is grounded through the first current-limiting resistance R11, the second divider resistance R2.
In the present embodiment, the first voltage VCC-IN of the first input end 1A input is through the first divider resistance R1
And second drive the first electronic switch Q1 to open after divider resistance R2 partial pressure, is triode in the first electronic switch Q1
When, it need to only guarantee that the both ends the second divider resistance R2 are greater than 0.7V and the first electronic switch Q1 opening can be driven.Together
When, in first input end 1A no-voltage input, the second divider resistance R2 can prevent the base stage of described three extreme Q1
Vacantly.
Preferably, second switching circuit 52 includes the second bleeder circuit 521 and the second electronic switch Q2, and described the
Two electronic switch Q2 include three ends, wherein
Described one end second electronic switch Q2 is connected to the first input end 1A through second bleeder circuit 521；
The second electronic switch Q2 other end is connected to the second switch circuit 4；
The second electronic switch Q2 further holds ground connection.
In the present embodiment, the second electronic switch Q2 is triode, and the base stage of the triode is through described second point
Volt circuit 521 is connected to the first input end 1A, and the collector of the triode is connected to the second switch circuit 4, institute
State the emitter ground connection of triode.The first voltage VCC-IN of the first input end 1A input is through second bleeder circuit
The second electronic switch Q2 is driven to open after 521 partial pressures, the second electronic switch Q2 drives the second switch when opening
Circuit 4 is closed, so that second switch circuit 4 is closed when first switch circuit 3 is connected.
It is understood that the second electronic switch Q2 can be other electronic switching devices such as metal-oxide-semiconductor etc., it is any to pass through
The design that transformation transistor types and quantity reach equifinality should be included in the protection scope of the utility model.
Preferably, second switching circuit 52 further includes the second current-limiting resistance R12, the first current-limiting resistance R12 company
It is connected between second bleeder circuit 521 and the second electronic switch Q2.
In the present embodiment, second current-limiting resistance is set to the base of the second electronic switch Q2 namely triode
Pole protects the PN junction of triode not damage because of high current.
Preferably, second bleeder circuit 521 includes third divider resistance R3 and the 4th divider resistance R4, wherein institute
It states the second electronic switch Q2 and is connected to the first input end 1A through the second current-limiting resistance R11, third divider resistance R3,
Meanwhile the second electronic switch Q2 is grounded through the second current-limiting resistance R12, the 4th divider resistance R4.
In the present embodiment, the first voltage VCC-IN of the first input end 1A input is through the third divider resistance R3
And the 4th drive the second electronic switch Q2 to open after divider resistance R4 partial pressure, is triode in the second electronic switch Q2
When, it need to only guarantee that the 4th divider resistance R4 both end voltage is greater than 0.7V and the second electronic switch Q2 opening can be driven.
Meanwhile in first input end 1A no-voltage input, the 4th divider resistance R4 can prevent hanging for described three extreme Q2
It is empty.
Specifically, the first switch circuit 3 includes third electronic switch Q3 and biasing resistor R30, in the present embodiment,
The third electronic switch Q3 is metal-oxide-semiconductor, and the source electrode of the third electronic switch Q3 is connected to the first input end 1A, described
The drain electrode of third electronic switch Q3 is connected to the common output end 2, and the biasing resistor R30 is connected across the third electronic cutting
Between the source electrode and grid for closing Q3, the grid of the third electronic switch Q3 is connected to the first electronic switch Q1 (triode)
Collector, the first input end 1A to first switching circuit 51 input first voltage VCC-IN when, described first
Switching circuit 51 controls the first electronic switch Q1 conducting, the third electricity connecting with the first electronic switch Q1 collector
The grid of sub switch Q3 (metal-oxide-semiconductor) is drawn as low level, the third electronic switch Q3 conducting, at this point, the first input end
The first voltage VCC-IN of 1A is transmitted to the common output end 2 through the third electronic switch Q3.
It is understood that the third electronic switch Q3 can be other electronic switching devices such as triode etc., Ren Hetong
Crossing the design that transformation transistor types reach equifinality with quantity should be included in the protection scope of the utility model.
Specifically, the second switch circuit 4 includes the 4th electronic switch Q4 and the first pull-up resistor R41, in this implementation
In example, the 4th electronic switch Q4 is triode, and the base stage of the 4th electronic switch Q4 is connected to second electronic cutting
The collector of Q2 (triode) is closed, and is connected to the second input terminal 1B through the first pull-up resistor R41, the described 4th
The collector of electronic switch Q4 is connected to the second input terminal 1B, and the transmitting collection of the 4th electronic switch Q4 is connected to described
Common output end 2.When the first input end 1A inputs first voltage VCC-IN to the second switch circuit 4, described the
Two electronic switch Q2 conducting, the base for the 4th electronic switch Q4 (triode) being connect with the second electronic switch Q2 collector
Pole is drawn as low level, the 4th electronic switch Q4 cut-off, at this point, the second voltage VDD of the second input terminal 1B can not
It is transmitted to the common input end.
When the first input end 1A no-voltage is input to the second switch circuit 4, the second electronic switch Q2
Cut-off, the base stage of the 4th electronic switch Q4 are high level by the first pull-up resistor R41 pull-up, and the 4th electronic switch Q4 is full
And the second voltage VDD is transmitted to described common defeated by conducting, the second input terminal 1B through the 4th electronic switch Q4
Outlet 2.
It is understood that the 4th electronic switch Q4 can be other electronic switching devices such as metal-oxide-semiconductor etc., it is any to pass through
The design that transformation transistor types and quantity reach equifinality should be included in the protection scope of the utility model.
In conclusion the second divider resistance R2 is by the first electronic switch Q1's when the input of first input end 1A no-voltage
Base stage is pulled down to low level, meanwhile, the second divider resistance R2 can prevent the first electronic switch Q1 base stage hanging, at this point, the first electricity
Sub switch Q1 cut-off, then the biasing resistor R30 no current of the grid of third electronic switch Q3 flows through, i.e. third electronic switch Q3's
Grid voltage Vg=source voltage Vs, third electronic switch Q3 cut-off.Meanwhile the 4th branch pressure voltage R4 by the second electronic switch
The base stage of Q2 is pulled down to low level, and the second electronic switch Q2 cut-off, then the base stage of the 4th electronic switch Q4 passes through the first pull-up electricity
Hindering R41 pull-up is high level, and the voltage VCC of the 4th electronic switch Q4 saturation conduction, at this time common input end output is equal to second
The second voltage VDD of input terminal 1B input, second voltage VDD are the output voltage of the internal electric source carried from device, namely
The operating voltage of I2C interface is the output voltage from the internal electric source of device.
When first input end 1A has first voltage VCC-IN input, the base level of the first electronic switch Q1 is second point
The partitioned level (V=(R2/ (R2+R1)) * VCC_IN) of piezoresistance R2 and the first divider resistance R1 only needs the second divider resistance
R2 both end voltage is greater than 0.7V, then the first electronic switch Q1 is connected, then the grid of third electronic switch Q3 is low level, at this point,
Pressure difference Vgs < 0 of third electronic switch Q3 grid and source electrode, third electronic switch Q3 conducting, the electricity of common input end output at this time
The operating voltage of the first voltage VCC-IN namely I2C interface that press VCC=first input end 1A input are the work electricity from device
Flat VCC_IN.Meanwhile second electronic switch Q2 base level be the 4th divider resistance R4 and third divider resistance R3 partial pressure
Level (V=(R4/ (R4+R3)) * VCC_IN) only needs the 4th divider resistance R4 both end voltage to be greater than 0.7V, then the second electronic cutting
Q2 conducting is closed, then the base stage of the 4th electronic switch Q4 is pulled low as low level, the 4th electronic switch Q4 cut-off.
Preferably, referring to Fig. 2, the I2C interface includes main device connecting pin 6, data signal end 7, clock signal terminal
8, the second pull-up resistor R42 and third pull-up resistor R43, wherein
The main device connecting pin 6 is connected to the first input end 1A；
The data signal end 7 is connected to the common output end 2 through the second pull-up resistor R42, and transmits data-signal
SDA；
The clock signal terminal 8 is connected to the common output end 2 through third pull-up resistor R43, and transmits clock signal
SCL。
In the present embodiment, when the first switch circuit 3 is closed and second switch circuit 4 is connected, the I2C interface
Operating voltage be the second input terminal 1B input that the second switch circuit 4 is sent second voltage VDD, described second
Voltage VDD is exported by the power supply carried from device, when the operating voltage of second voltage VDD and the main device mismatches,
It will lead to the main device and from normal communication is unable between device, the present embodiment pass through the second pull-up resistor R42, third
The voltage of data signal end 7, clock signal terminal 8 is pulled to the operating voltage with the main device by pull-up resistor R43 respectively
Match, guarantees main device and from the normal communication between device.
In addition, to achieve the above object, the utility model also provides a kind of electronic equipment, the electronic equipment includes main device
Part and from device, the main device includes first power supply with the first input end 1A, and described from device includes having institute
State the second source of the second input terminal 1B, it is described from device further include the voltage follower circuit stated such as any of the above-described, it is described from
Device is connect through the I2C interface with the main device.
In the present embodiment, the first power supply of the main device exports the first voltage VCC-IN, described out of device
The included second source in portion exports second voltage VDD, passes through the first electricity of first input end 1A output in first power supply
When pressing VCC-IN, the first switch circuit 3 conducting and using the first voltage VCC-IN of first input end 1A input as
The operating voltage of the I2C interface, so that main device and realizing normal communication from the voltage matches between device.It can manage
Solution, the first voltage VCC-IN of first input end 1A input can there are many, the operating voltage of the I2C interface is drawn high
To corresponding first voltage VCC-IN, principal and subordinate's device normal communication can be realized, to improve the I2C of principal and subordinate's device group composition
The compatibility of system；In first input end 1A no-voltage input, enable from the second source that device carries from described the
Two input terminal 1B are to 4 output voltage of second switch circuit, the conducting of second switch circuit 4 and by second input terminal
Operating voltage of the voltage as the I2C interface of 1B input, guarantee main device and between device being capable of normal communication.
Referring to Fig. 3, Fig. 3 show from device for example camera module, sensor, EEPROM, Driver IC control electricity
Road U1, wherein pin A0-A3 is address pin, and GND is grounding pin, and VCC is power pins, and WP is erasing protection pin,
SCL is clock pins, and SDA is data pin.The voltage VCC of common output end output can synchronize as foot A0-A3, VCC and
WP power supply.It wipes protection pin and the 5th divider resistance R5 is connected to the common output end, and through the 6th divider resistance
R6 ground connection, the power pins VCC is grounded through filter capacitor, the clock pins SCL be connected to the interface chip J1 when
Clock signal end 8, the data pin SDA are connected to the data signal end 7 of the interface chip J1.
The voltage follower circuit of the utility model and electronic equipment with the voltage follower circuit at least have following
Effect:
(1) using the voltage follower circuit of discrete part composition not only instead of level conversion class chip, also synchronous section
Level conversion class circuit has been saved, has not only simplified circuit design, and reduce design cost.
(2) adjustable from the pull-up level of device inside.For distinct electronic apparatuses, the work of I2C interface (I2C bus)
Level may be different.The utility model can be inputted first voltage VCC-IN by first input end 1A and adjust I2C interface work electricity
It is flat, to meet different I2C system communication level demands, improve the compatibility of system.
(3) it when this input of main device no-voltage, enables and works from equipment is self-powered for I2C interface.
(4) the case where carrying pull-up circuit from the I2C interface of equipment, being inputted for main device no-voltage, principal and subordinate's device
Operation level can mismatch, and will be pulled upward to, guarantee I2C system consistent with main device from the operating voltage of device by pull-up circuit
Normal work, improve the use popularity of the voltage follower circuit.
The above is only the preferred embodiments of the utility model, and therefore it does not limit the scope of the patent of the utility model, all
Equivalent structure or equivalent flow shift made based on the specification and figures of the utility model, is applied directly or indirectly in
Other related technical areas are also included in the patent protection scope of the utility model.
Claims (10)
1. a kind of voltage follower circuit, which is characterized in that voltage follower circuit includes first input end, the second input terminal, common
Output end, first switch circuit, second switch circuit and switch switching circuit；
The input terminal of the first switch circuit is connected to the output end connection of the first input end, the first switch circuit
To the common output end；
The input terminal of the second switch circuit is connected to the output end connection of second input terminal, the second switch circuit
To the common output end；
The input terminal of the switch switching circuit is connected to first input end, two output ends difference of the switch switching circuit
First switch circuit and the second switch circuit are connected to control the first switch circuit and the second switch circuit
Select a conducting；
Wherein, the common output end is connected to I2C interface.
2. voltage follower circuit as described in claim 1, which is characterized in that the switch switching circuit includes the first switching electricity
Road and the second switching circuit, wherein
First switching circuit connects the first input end and the first switch circuit；
Second switching circuit connects the first input end and the second switch circuit.
3. voltage follower circuit as claimed in claim 2, which is characterized in that first switching circuit includes the first partial pressure electricity
Road and the first electronic switch, first electronic switch include three ends, wherein
First electronic switch one end is connected to the first input end through first bleeder circuit；
The first electronic switch other end is connected to the first switch circuit；
First electronic switch further holds ground connection.
4. voltage follower circuit as claimed in claim 3, which is characterized in that first switching circuit further includes the first current limliting
Resistance R11, the first current-limiting resistance R11 are connected between first bleeder circuit and the first electronic switch.
5. voltage follower circuit as claimed in claim 4, which is characterized in that first bleeder circuit includes the first partial pressure electricity
Hinder R1 and the second divider resistance R2, wherein
First electronic switch is connected to the first input end through the first current-limiting resistance R11, the first divider resistance R1,
Meanwhile first electronic switch is grounded through the first current-limiting resistance R11, the second divider resistance R2.
6. voltage follower circuit as claimed in claim 2, which is characterized in that second switching circuit includes the second partial pressure electricity
Road and the second electronic switch, second electronic switch include three ends, wherein
Second electronic switch one end is connected to the first input end through second bleeder circuit；
The second electronic switch other end is connected to the second switch circuit；
Second electronic switch further holds ground connection.
7. voltage follower circuit as claimed in claim 6, which is characterized in that second switching circuit further includes the second current limliting
Resistance R12, the second current-limiting resistance R12 are connected between second bleeder circuit and the second electronic switch.
8. voltage follower circuit as claimed in claim 7, which is characterized in that second bleeder circuit includes third partial pressure electricity
Hinder R3 and the 4th divider resistance R4, wherein second electronic switch is through the second current-limiting resistance R11, third divider resistance
R3 is connected to the first input end, meanwhile, second electronic switch is through the second current-limiting resistance R12, the 4th partial pressure electricity
Hinder R4 ground connection.
9. such as the described in any item voltage follower circuits of claim 1-8, which is characterized in that the I2C interface includes main device
Connecting pin, data signal end, clock signal terminal, the second pull-up resistor R42 and third pull-up resistor R43, wherein
The main device connecting pin is connected to the first input end；
The data signal end is connected to the common output end through the second pull-up resistor R42；
The clock signal terminal is connected to the common output end through third pull-up resistor R43.
10. a kind of electronic equipment, which is characterized in that the electronic equipment includes main device and from device, and the main device includes
The first power supply with first input end, it is described from device include the second source with the second input terminal, it is described from device packet
Include further include such as the described in any item voltage follower circuits of claim 1-9, it is described from device through the I2C interface and the master
Device connection, the first input end of first power supply are connect with the first input end of the voltage follower circuit, and described second
Second input terminal of power supply is connect with the second input terminal of the voltage follower circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920050996.5U CN209168092U (en) | 2019-01-11 | 2019-01-11 | Voltage follower circuit and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920050996.5U CN209168092U (en) | 2019-01-11 | 2019-01-11 | Voltage follower circuit and electronic equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN209168092U true CN209168092U (en) | 2019-07-26 |
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ID=67328289
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920050996.5U Active CN209168092U (en) | 2019-01-11 | 2019-01-11 | Voltage follower circuit and electronic equipment |
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| Country | Link |
|---|---|
| CN (1) | CN209168092U (en) |
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2019
- 2019-01-11 CN CN201920050996.5U patent/CN209168092U/en active Active
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Effective date of registration: 20201022 Address after: 261031 north of Yuqing street, east of Dongming Road, high tech Zone, Weifang City, Shandong Province (Room 502, Geer electronic office building) Patentee after: GoerTek Optical Technology Co.,Ltd. Address before: 266104 Laoshan Qingdao District North House Street investment service center room, Room 308, Shandong Patentee before: GOERTEK TECHNOLOGY Co.,Ltd. |
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