Utility model content
The technical problems to be solved in the utility model is to avoid above-mentioned the deficiencies in the prior art part and propose a kind of profit
The time-sharing multiplex circuit of LED control and key-press input is carried out with same terminal.
Solving the technical scheme that above-mentioned technical problem uses is:It is a kind of to carry out LED control and button using same terminal
The time-sharing multiplex circuit of input includes control signal input for cyclic control signal input, for external LED lamp
Push button signalling lead-out terminal of the switch control with the input and output terminal of key-press input time-sharing multiplex and for push button signalling output;
The time-sharing multiplex circuit includes switch metal-oxide-semiconductor, No.1 current source, No. two current sources and the electric current for being used for control signal input
Mirror;The grid of the switch metal-oxide-semiconductor is used as control signal input of cyclic control signal input;The No.1 current source
Positive pole and No. two current sources positive pole all with positive source electrically connect;The negative pole and No.1 resistance of the No.1 current source
One end electrical connection;The other end of the No.1 resistance electrically connects with one end of No. two resistance;The other end of No. two resistance
Electrically connected with the low current input of the current mirror;The High-current output end of the current mirror is negative with No. two current sources
Pole electrically connects, and is used as push button signalling lead-out terminal;The drain electrode of the switch metal-oxide-semiconductor or source electrode connect positive source;The switch
Metal-oxide-semiconductor is another not to connect the source electrode electrically connected with positive source or drain electrode, connects with one end of No.1 resistance and one end of No. two resistance
Connect, the input and output terminal as time-sharing multiplex.
The current mirror includes No. five NMOS tubes and No. six NMOS tubes;The grid of No. five NMOS tubes and described No. six
The grid electrical connection of NMOS tube;The drain electrode electrical connection of the grid of No. five NMOS tubes and No. five NMOS tubes is used as the electricity
Flow mirror low current input;The source electrode of No. six NMOS tubes and the source electrode of No. five NMOS tubes electrically connect and are used as the electricity
Flow the earth terminal of mirror;High-current output end of the drain electrode as the current mirror of No. six NMOS tubes.
The No.1 current source includes built-in current source, No.1 PMOS and No. two PMOSs;No. two current source bags
Include No. three PMOSs;The source electrode of the No.1 PMOS, No. two PMOSs and No. three PMOSs three PMOSs
Connect the positive pole that power supply VCC is used as the No.1 current source;The No.1 PMOS, No. two PMOSs and No. three PMOS
Manage the grid electrical connection of three PMOSs;The drain electrode electrical connection of the grid of the No.1 PMOS and the No.1 PMOS,
And electrically connected with the positive pole in the built-in current source;The negative pole ground connection in the built-in current source;The leakage of No. two PMOSs
Pole is used as the negative pole of the No.1 current source;The source electrode of No. three PMOSs is used as the positive pole of No. two current sources;It is described
Negative pole of the drain electrode as No. two current sources of No. three PMOSs.
The switch metal-oxide-semiconductor is No. four PMOSs;The source electrode of No. four PMOSs connects positive source;No. four PMOS
The drain electrode of pipe with No.1 resistance and No. two resistance electrical connections by being used as being electrically connected with the electrical connection of external LED lamp and input button
The input and output terminal connect.
The switch metal-oxide-semiconductor is No. nine NMOS tubes;The drain electrode of the NMOS tube connects positive source;The source electrode of the NMOS tube
By the input for being used as with the electrical connection of external LED lamp and inputting button electrical connection with No.1 resistance and No. two resistance electrical connections
Lead-out terminal.Described time-sharing multiplex circuit includes No.1 phase inverter and No. two phase inverters;The input of the No.1 phase inverter
Control signal input as cyclic control signal input;The output end of the No.1 phase inverter and switch metal-oxide-semiconductor
Grid electrically connects;The input of No. two phase inverters electrically connects with the negative pole of No. two current sources;No. two phase inverters
Output end be used as push button signalling lead-out terminal;No. two phase inverters are Schmitt phase inverter.
Solve the technical scheme that above-mentioned technical problem uses can also be:LED control is carried out using same terminal and is pressed
The time sharing multiplex control method of key input, including:Step 1:Periodicity control for the control of input and output terminal time-sharing multiplex
Signal inputs from control signal input;The cyclic control signal includes LED control time section and push button signalling inputs
Detection time section;Step 2:In LED control time section, pass through the Automatic level control time-sharing multiplex circuit of cyclic control signal
Lighting control state is operated in, and the LED control signal for controlling LED to switch is exported according to illumination control signal;Step
Rapid 3:In push button signalling input detection time section, it is operated in by the Automatic level control time-sharing multiplex circuit of cyclic control signal
Key-press input detects state, and external key input is converted to by key output signal.
The current ratio scope of the electric current of the No.1 current source and No. two current sources is 1:1 to 1:2.
The current ratio scope at the current mirror low current input and High-current output end is 1:4 to 1:8.
The cycle of the cyclic control signal is more than or equal to 24 hertz.
Compared with the existing technology compared with, the beneficial effects of the invention are as follows:Button uses electric current with LED time-sharing multiplex circuit
Mirror, a terminal can be used to realize that the comparison of key-press input level obtains key-press input signal, while can also be used using the terminal
Controlled in the switch of LED, the structure of circuit is very simple, it is not necessary to reference voltage, saves the device count of chip, also can
To reduce the cost of chip.
Embodiment
Embodiment of the present utility model is further described below in conjunction with each accompanying drawing.
A kind of time-sharing multiplex circuit that LED control and key-press input are carried out using same terminal as shown in Figures 2 to 4
In 100 embodiment, including input for cyclic control signal control signal input, for external LED lamp switch
Push button signalling lead-out terminal of the control with the input and output terminal of key-press input time-sharing multiplex and for push button signalling output;It is described
Time-sharing multiplex circuit 100 include be used for control signal input switch metal-oxide-semiconductor M5, No.1 current source I1, No. two current source I2 and
Current mirror I3;The grid of the switch metal-oxide-semiconductor M5 is used as control signal input of cyclic control signal input;Described one
Number current source I1 positive pole and the positive pole of No. two current source I2 all electrically connect with positive source VCC;The No.1 current source
One end electrical connection of I1 negative pole and No.1 resistance R1;One end of the other end and No. two resistance R2 of the No.1 resistance R1 is electrically connected
Connect;The other end of No. two resistance R2 electrically connects with the low current input of the current mirror I3;The current mirror I3's is big
Current output terminal electrically connects with the negative pole of No. two current source I2, and is used as push button signalling lead-out terminal;The switch metal-oxide-semiconductor
M5 drain electrode or source electrode meet positive source VCC;Another source electrodes not connect with positive source VCC electrical connections of switch metal-oxide-semiconductor M5
Or drain electrode, it is connected with No.1 resistance R1 one end and No. two resistance R2 one end, the input and output terminal as time-sharing multiplex.
As shown in Figs. 3-4, the current mirror I3 includes No. five NMOS tube NM305 and No. six NMOS tube NM306;Described five
The grid electrical connection of number NMOS tube NM305 grid and No. six NMOS tube NM306;The grid of No. five NMOS tube NM305
Pole and No. five NMOS tube NM305 drain electrode electrical connection are used as the current mirror I3 low current inputs;No. six NMOS
Pipe NM306 source electrode and No. five NMOS tube NM305 source electrode electrically connect and are used as the earth terminal of the current mirror I3;It is described
No. six NMOS tube NM306 High-current output end of the drain electrode as the current mirror I3.
As shown in Figs. 3-4, the No.1 current source I1 includes built-in current source I210, No.1 PMOS PM201 and No. two
PMOS PM202;No. two current source I2 include No. three PMOS PM203;It is the No.1 PMOS PM201, described No. two
The source electrode of PMOS PM202 and No. three PMOS PM203 three PMOSs meets power supply VCC and is used as the No.1 current source
I1 positive pole;The No.1 PMOS PM201, No. two PMOS PM202 and No. three PMOS PM203 this three
The grid electrical connection of PMOS;The drain electrode of the grid of the No.1 PMOS PM201 and the No.1 PMOS PM201 is electrically connected
Connect, and electrically connected with the positive pole of the built-in current source I210;The negative pole ground connection of the built-in current source I210;Described No. two
PMOS PM202 negative pole of the drain electrode as the No.1 current source I1;The source electrode of No. three PMOS PM203 is used as described
No. two current source I2 positive pole;Negative pole of the drain electrode as No. two current source I2 of No. three PMOS PM203.
As shown in figure 3, the switch metal-oxide-semiconductor M5 is No. four PMOS PM204;The source electrode of No. four PMOS PM204
Meet positive source VCC;The drain electrode of No. four PMOS PM204 with No.1 resistance R1 and No. two resistance R2 electrical connections by using
Make to electrically connect and input the input and output terminal that button electrically connects with external LED lamp.
As shown in figure 3, a kind of button and LED time-sharing multiplex circuit, including PMOS PM201, PM202, PM203,
PM204, NMOS tube NM305, NM306, resistance R1, R2, current source I210, phase inverter IVT1, Schmitt phase inverter IVT2;At this
In embodiment, PMOS PM201 drain electrode meets current source I210, and its grid connects with drain electrode, PMOS PM201, PM202,
PM203 source electrode meets power supply VCC, their grid connection composition current mirror;The electricity that PMOS PM201, PM202, PM203 flow through
Stream ratio is 1:1:2, PMOS PM202 drain electrode connect No.1 resistance R1 one end, and No.1 resistance R1 another termination input is defeated
Go out terminal, i.e. KEY pin in Fig. 3.
As shown in figure 3, NMOS tube NM305 drain electrode connects No. two resistance R2 one end, No. two resistance R2 another termination
KEY pin in input and output terminal, i.e. Fig. 3;NMOS tube NM305 grid connects with drain electrode, NMOS tube NM305's and NM306
Source ground, their grid connection composition current mirror;The current ratio that NMOS tube NM305 and NM306 flows through is 1:8, No. four
PMOS PM204 drain electrode connection NMOS tube NM306 drain electrode, input signal, Schmitt are provided for Schmitt phase inverter IVT2
The output of phase inverter is push button signalling lead-out terminal;No. four PMOS PM204 source electrode meets power supply VCC, and its drain electrode connects input
Lead-out terminal is the KEY pin in Fig. 3, and its grid meets No.1 phase inverter IVT1, and the input of No.1 phase inverter is defeated for control signal
Enter terminal, illumination control signal is inputted from the terminal.
Cyclic control signal is illustrated in figure 5, its cycle is T;Cycle T is divided into T1 and two periods of T2,
The T1 periods, it is allowed to which illumination LED is bright, in the T2 periods, makes illumination LED go out, it is allowed to which button detects.
As shown in figure 3, when if the instruction of outside input needs the illumination LED to close, cyclic control signal level is low
Level, No. four PMOS PM204 cut-offs make illuminating LED lamp go out;If illumination LED works, cyclic control signal is used as LED
The illumination control signal of lamp, now cyclic control signal is switching signal.
In the T1 periods, cyclic control signal level is high level, and No. four PMOS PM204, which are opened, allows illumination LED
Lamp is bright or closes, and in the T1 periods, the cyclic control signal can be the switching signal of low and high level, control bright LED to open
Or close;In the T1 periods, PMOS PM201, PM202, PM203 are to open, and NMOS tube NM305 and NM306 is also what is opened.
In the T1 periods, if illumination LED is closed, No. four PMOS PM204 cut-offs, no matter whether button is pressed, illumination
LED is all gone out;If illumination LED works, No. four PMOS PM204 are opened, and power supply VCC powers to illuminating LED lamp, power supply
VCC voltages are significantly larger than the conduction voltage drop of illuminating LED lamp, make illuminating LED lamp bright;Now No. two resistance R2 limitations flow to NOMS pipes
NM305 current value, illuminating LED lamp will be flowed to by ensureing No. four PMOS PM204 drain current;Due to the visual frequency of human eye
Less than 24Hz, cycle T frequency is set to be significantly larger than 24Hz, then the brightness for seeing LED is exactly continuous.
In the T2 periods, cyclic control signal level low level, No. four PMOS PM204 cut-offs make illuminating LED lamp go out,
Carry out button detection;In T2 periods, No. four PMOS PM204 cut-offs, if button is pressed, NMOS tube NM305 and NM306 is cut
Only, NMOS tube NM306 drain voltage is power supply VCC, i.e. Schmitt phase inverter IVT2 input signal is high level;If press
Key is not pressed, because the current ratio that NMOS tube NM305 and NM306 flows through is 1:8, PMOS PM201, PM202, PM203
The current ratio flowed through be 1:1:2, because the electric current for flowing through NMOS tube NM306 is much smaller than setting value, NMOS tube NM306
Drain voltage be low level, i.e., the input signal of level signal, i.e. Schmitt phase inverter IVT2 that voltage relatively is zero
For low level, the low and high level signal exported by Schmitt phase inverter IVT2 is it may determine that whether button is pressed.
In the T2 periods, if button is not pressed, grid source electricity of the voltage equal to NMOS tube NM305 of input and output terminal
VGS is pressed plus No. two resistance R2 voltage, setting this voltage, illuminating LED lamp is to go out much smaller than the conducting pressure pressure drop of illuminating LED lamp
's;If button is pressed, the voltage of input and output terminal is low level, i.e., the level signal that voltage relatively is zero, shines
Bright LED is also what is gone out.
As shown in figure 4, the switch metal-oxide-semiconductor M5 is No. nine NMOS tube NM309;The drain electrode of the NMOS tube NM309 connects electricity
Source positive pole VCC;The source electrode of the NMOS tube NM309 with No.1 resistance R1 and No. two resistance R2 electrical connections by being used as with outside
LED electrically connects and the input and output terminal of input button electrical connection.
In the difference of the embodiment shown in the embodiment and Fig. 3 of a kind of button as shown in Figure 4 and LED time-sharing multiplex circuit
Different to be, the switch metal-oxide-semiconductor M5 is No. nine NMOS tube NM309.It should be noted that the switch metal-oxide-semiconductor M5 can also by for
Changing other into has the pipe or circuit of equivalent circuit characteristic, can be by the cyclic control signal access of input simultaneously as long as can play
Receive its its control.
In the difference of the embodiment shown in the embodiment and Fig. 3 of a kind of button as shown in Figure 4 and LED time-sharing multiplex circuit
Different to also reside in, PMOS PM201, PM202, PM203 current ratio flowed through are 1:1:1;NMOS tube NM305 and NM306 flows
The current ratio crossed is 1:4.
As shown in Figs. 3-4, including No.1 phase inverter IVT1 and No. two phase inverter IVT2;The No.1 phase inverter IVT1's
Input is used as control signal input of cyclic control signal input;The output end of the No.1 phase inverter IVT1 is with opening
Close metal-oxide-semiconductor M5 grid electrical connection;The negative pole of the input and No. two current source I2 of No. two phase inverter IVT2 is electrically connected
Connect;The output end of No. two phase inverter IVT2 is used as push button signalling lead-out terminal;No. two phase inverter IVT2 are Schmitt
Phase inverter.
As shown in figure 5, a kind of carry out LED control using same terminal based on above-mentioned time-sharing multiplex circuit 100 and press
The time sharing multiplex control method of key input, including:Step 1:Periodicity control for the control of input and output terminal time-sharing multiplex
Signal inputs from control signal input;The cyclic control signal includes LED control time section T1 and push button signalling is defeated
Enter detection time section T2;Step 2:In LED control time section T1, answered by the Automatic level control timesharing of cyclic control signal
Lighting control state is operated in circuit 100, and the LED control for controlling LED to switch is exported according to illumination control signal
Signal processed;Step 3:In push button signalling input detection time section T2, answered by the Automatic level control timesharing of cyclic control signal
Key-press input detection state is operated in circuit 100, and external key input is converted to by key output signal.
The electric current of the No.1 current source I1 and No. two current source I2 current ratio scope are 1:1 to 1:2.The electric current
The current ratio scope at mirror I3 low currents input and High-current output end is 1:4 to 1:8;The both ends output of the current mirror I3
Current ratio include 1:8.
No.1 current source I1 described above electric current and No. two current source I2 current ratio need and the current mirror I3
Low current input and the current ratio at High-current output end need to match each other, to realize specific level comparison, when
When comparison relation changes, the current ratio of each current mirror can be adjusted as needed to obtain suitable output.
The cycle of the cyclic control signal is more than or equal to 24 hertz.May also be other be more than human eye sensitivity's frequency its
His in cycle.Can also according to be actually needed adjustment a cycle in LED control time section T1 and push button signalling input detection when
Between section T2 period distribution.
Advantageous effects of the present utility model are:Button uses current mirror with LED time-sharing multiplex circuit, can use one
Individual terminal realizes that the comparison of key-press input level obtains key-press input signal, while the terminal can also be used to be used for opening for LED
Control is closed, the structure of circuit is very simple, it is not necessary to reference voltage, save the device count of chip, also can reduces chip
Cost.
The time-sharing multiplex circuit and controlling party of the control of LED switch and push button signalling input are carried out using same terminal
Method, from the cyclic control signal of the input and output terminal time-sharing multiplex control of control signal input son input;This is periodically
Control signal includes LED control time section T1 and push button signalling input detection time section T2;In LED control time section T1
Interior, circuit is according to illumination control signal control LED switch;In push button signalling input detection time section T2, circuit is by outside
Key-press input is converted to by key output signal;The circuit only includes switch two current sources of metal-oxide-semiconductor and an electric current
Mirror, it is simple in construction, without setting comparator and reference voltage, with extremely low into the local time-sharing multiplex work(for realizing a terminal
Energy.
Separately it should be noted that, for convenience, the electronic component such as NMOS tube, NMOS tube, resistance, electric capacity all employs
First, second-class serial number, these serial numbers do not represent its position or restriction sequentially, and it is convenient to be intended merely to description.
Any feature disclosed in this specification, unless specifically stated otherwise, can be by other equivalent or with similar purpose
Alternative features are replaced.I.e. unless specifically stated otherwise, each feature is an example in a series of equivalent or similar characteristics
.
Embodiment of the present utility model is the foregoing is only, not thereby limits the scope of the claims of the present utility model, it is every
The equivalent structure or equivalent flow conversion made using utility model specification and accompanying drawing content, or directly or indirectly it is used in it
The technical field of his correlation, is similarly included in scope of patent protection of the present utility model.