CN1258682C

CN1258682C - Use a single bit to detect a network of multiple outlets

Info

Publication number: CN1258682C
Application number: CN 02155289
Authority: CN
Inventors: 谢文龙; 曾志宏
Original assignee: C Media Electronics Inc
Current assignee: C Media Electronics Inc
Priority date: 2002-12-12
Filing date: 2002-12-12
Publication date: 2006-06-07
Anticipated expiration: 2022-12-12
Also published as: CN1506690A

Abstract

The invention discloses a network for detecting multiple sockets by using a single bit, which comprises a plurality of sockets with dome switches, a plurality of resistors which are coupled together in series through dome switches in the sockets respectively followed by the plurality of resistors, and a voltage dividing resistor. The plurality of resistors are connected in series or not according to the state of the socket, and the elastic sheet switch is connected in parallel with the resistors to perform voltage division. The voltage dividing resistor divides the voltage through the parallel coupled resistors to obtain the output voltage of the output node so as to judge the number of the inserted sockets and determine the positions. A first terminal of the network for detecting the multiple sockets is connected to a first reference potential, and the first terminal is a common terminal of a first socket and a corresponding resistor in the plurality of sockets; and a second terminal of the network for detecting the multiple sockets is connected to a second reference potential, the second terminal being a common terminal of a last socket of the plurality of sockets and the corresponding resistor.

Description

Use single bit to detect the networking of multiple socket

Technical field

The present invention is relevant with a kind of device that detects multiple socket, specifically, relates to a kind of resistor networking of using single bit to detect multiple socket.

Background technology

All possess usually in the electronic product relevant with image, sound at present many connection terminals are arranged, the confession user is connected on other external device (ED)s, is beneficial to mutual input, output and transmitting signals.At this wherein, what be widely adopted most is mini earphone terminal, especially on computer system.Its main cause is that this terminal volume is little, does not occupy the area of panel again.And on earphone socket, whether having any plug to exist at present for computer system can be detected, relevant processing is done by the system of being beneficial to, and generally adopts a kind of earphone socket of subsidiary elastic sheet switch.As shown in Figure 1a, the pin 3 of earphone socket and 4 is two signal contacts, and pin 5 is the common reference points of described just now two signal contacts, and

1 and 2 is described just now elastic sheet switchs.The elastic sheet switch of commercially available prod generally is designed to be open-circuit condition (open) when plug inserts at present; Otherwise be short circuit (close or short), shown in Fig. 1 b, i.e. the situation of earphone socket when having plug to insert.Utilize this conventional art, we can install a resistance and a reference voltage VDD additional on switch, shown in Fig. 1 a and Fig. 1 b, and obtain the insertion state of earphone socket from node " Read back ".With this example, if no plug inserts node " Read back " then by the interior elastic sheet switch of socket 1 (Jack 1) be coupled to " " current potential, so will locate to obtain at node " Read back " " " current potential; And when having plug to insert, then because elastic sheet switch is the resistance coupling of open circuit node " Read back " by 10K Ω will obtain " VDD " current potential.If change the elastic sheet switch that when having plug to insert, is short-circuit condition into, then situation and the above-mentioned opposite states on the node " Read back ". Therefore system is as long as the current potential that detection node " Read back " is located can learn just whether socket 1 (Jack) has plug to exist at present.Above detection mode is that each earphone socket must have " Read back " node, and promptly along with the increasing of earphone socket quantity, the quantity of node " Read back " also can be along with increase.

If testing circuit is incorporated in the single integrated circuit, then many nodes " Read back " all need be sent in this integrated circuit.This will increase the pin count and the cost of integrated circuit.

For this reason, have what earphone sockets to need to detect no matter how to provide a kind of, the pin that all only needs an integrated circuit is that grinding of creator created the motivation place among the present invention.

Summary of the invention

The networking of using single bit to detect multiple socket among the present invention mainly is must be furnished with " Read back " node in order to solve existing each socket, causes the problem that also increases IC bond number and cost that increases along with socket.

The networking of using single bit to detect multiple socket among the present invention includes:

A plurality of sockets, these a plurality of sockets include elastic sheet switch;

A plurality of resistance, series coupled is together by the elastic sheet switch of its described a plurality of sockets of following respectively for these a plurality of resistance, state by above-mentioned a plurality of sockets decides its series connection whether to shunt, and the elastic sheet switch of above-mentioned a plurality of sockets is in parallel with described a plurality of electric resistance partial pressures;

Divider resistance, this divider resistance and the divider resistance of described a plurality of parallel coupled dividing potential drop in parallel again, and get the number that can judge the insertion socket and the output voltage of determining the output node of position;

First end points at the networking of the multiple socket of wherein said detection is connected to first reference potential, and this first end points that detects the networking of multiple socket is meant in above-mentioned a plurality of socket the common ends of corresponding resistance in first socket and a plurality of resistance; Second end points at the networking of the multiple socket of described detection is connected to second reference potential, and this second end points that detects the networking of multiple socket is meant in a plurality of sockets the common ends of corresponding resistance in last socket and a plurality of resistance.

In addition, the networking of using single bit to detect multiple socket among the present invention also can include:

A plurality of resistance, parallel coupled is together by first contact of elastic sheet switch in its a plurality of sockets of following respectively for these a plurality of resistance, state by above-mentioned a plurality of sockets decides its in parallel whether shunting, and the elastic sheet switch of above-mentioned a plurality of sockets is connected with described a plurality of electric resistance partial pressures;

Divider resistance, this divider resistance and the described a plurality of series coupled divider resistances dividing potential drop of connecting again, and can judge number that inserts socket and the output voltage of determining the output node of position; And

The divider resistance at the networking of the multiple socket of wherein above-mentioned detection is connected to first reference potential;

And second contact of elastic sheet switch is connected to second reference potential in a plurality of sockets.

In addition, active resistance in series networking can be adopted in the networking of using single bit to detect multiple socket among the present invention, and it includes:

Parallel coupled and decides its in parallel whether shunting by the state of above-mentioned a plurality of sockets together by first contact of elastic sheet switch in its a plurality of sockets of following respectively for a plurality of resistance, these a plurality of resistance;

Divider resistance, the common ends of above-mentioned a plurality of resistance are connected to first end of this divider resistance;

One inverting amplifier OPA, the OP end of this inverting amplifier OPA is connected to second end of described divider resistance; And

The common end points of wherein said each elastic sheet switch is connected to first reference potential, the IP end of described inverting amplifier OPA is connected to second reference potential, the IN of this inverting amplifier OPA end is connected to the common end points of a plurality of resistance, and in this networking the common ends point measurement output voltage of each elastic sheet switch.

In addition, active parallel resistance networking also can be adopted in the networking of using single bit to detect multiple socket among the present invention, and it includes:

From the above, no matter what sockets the resistor networking of using single bit to detect multiple socket among the present invention has need to detect, all only needing the pin position of an integrated circuit to detect to judge which socket has plug to insert, thereby can reduce the pin count of integrated circuit, reduces cost.

Description of drawings

The specific embodiment of the utility model is described in further detail below in conjunction with accompanying drawing.

Fig. 1 a is the structural representation of socket circuit in the conventional art;

Fig. 1 b is the structural representation of circuit shown in Fig. 1 a when inserting plug;

Fig. 2 uses single bit to detect the networking circuit diagram of multiple socket among the present invention;

Fig. 3 uses single bit to detect the truth table synoptic diagram at multiple socket networking among the present invention;

Fig. 4 uses single bit to detect another enforcement illustration of networking of multiple socket among the present invention;

Fig. 5 a is that the present invention uses single bit to detect the active resistance in series networking synoptic diagram at multiple socket networking;

Fig. 5 b is that the present invention uses single bit to detect the active parallel resistance networking synoptic diagram at multiple socket networking, and output voltage shown in this figure is the state effect of linear change.

Embodiment

The circuit of describing in above-mentioned conventional art, each socket must have " Readback " node, and in other words, when having multiple socket, the quantity of node " Read back " is also along with increase, thereby have increased the quantity and the cost of pin relatively.The present invention has then provided a kind of mode of connection and structure, utilizes this wiring construction and mode, no matter there are what sockets to need to detect, only needs the pin of an integrated circuit to get final product in principle.

As shown in Figure 2, the networking of using single bit to detect multiple socket among the present invention includes four sockets, must be noted that the number of this socket can dispose arbitrarily according to demand.And cited in the present embodiment number is only done an explanation, is not to be used to limit the present invention.And adopt the elastic sheet switch parallel resistance to carry out dividing potential drop in this embodiment.Resistance R 1, R2, R3, R4 are that series coupled is together by the elastic sheet switch of its four earphone sockets of following respectively in this circuit, state by earphone socket decides its series connection whether to shunt, carry out dividing potential drop with the resistance R 5 of parallel coupled again, thereby obtain the output voltage of dividing potential drop node " Read back ".

As shown in Figure 2, each socket all includes the

1,2 of elastic sheet switch, and the

3,4 of earphone socket is two signal contacts, and pin 5 is the common reference points of signal.The

1,2 of each socket is parallel with a resistance, as R1, R2, R3 and R4.These four sockets and four resistance constitute a multiple socket networking, and the first end N1 at multiple socket networking is meant the common ends of first socket, first pin and corresponding resistance R 1, and this first end is connected to first reference potential, as VDD.The second end N2 at multiple socket networking is meant second pin of the 4th socket and the common ends of corresponding resistance R 4.Other has one second reference potential, as " " current potential, this " " be connected with one the 5th resistance R 5 between current potential and the second end points N2.By with the voltage distribution of the R5 magnitude of voltage of node " Read back " as can be known, judge number and definite position of inserting socket to provide.

In the present embodiment, one has four earphone sockets, if according to demand, can also expand arbitrarily or reduce the socket number, one has five resistance in the foregoing description in addition, and the resistance of these five resistance is identical.It should be noted that in Fig. 2 if the VDD changing-over is become " " current potential, and with original " " the current potential changing-over is to VDD, then still meets the design concept of primary circuit.Suppose that all sockets all do not have plug and insert, then because node " Read back " will be coupled to power vd D by the elastic sheet switch of four series connection, by circuit theory as can be known, the current potential of node " Read back " is VDD (if reversal connection, then is " " current potential).If there is any one socket to insert plug, then node " Read back " is directly coupled to power vd D.But through one among resistance R 1, R2, R3 or the R4.Because the resistance that present embodiment adopts has identical impedance, thus by with the voltage distribution of R5 as can be known the voltage of node " Read back " be VDD/2.Can certainly adopt different impedances according to needs.

Suppose that not only a plug inserts among these four earphone sockets, then the voltage of " Read back " will be lower again than VDD/2 as can be known by circuit theory.After this point voltage sent into integrated circuit, only need one simple " comparer " (Comparator), can tell its magnitude of voltage and be VDD or below the 1/2VDD, thereby can learn whether any plug insertion socket is arranged, and the quantity of insertion socket.

Only need " Read back " node can detect the insertion state of a plurality of earphone sockets in the present embodiment, but can not tell the state of each socket, promptly which socket has plug to insert.Yet we can further adjust the resistance of the resistance that indivedual earphone socket arranges in pairs or groups, and make indivedual sockets different situations can occur when having inserted plug, to produce different " Read back " node voltages, differentiate for testing circuit.Even, under multiple insertion situation, still provide different information to testing circuit.Though have only " Read back " node that information is provided, the information amount that it provides and a plurality of " Read back " node provided do not have different.

As shown in Figure 3, list the resistance value through adjusting in the foregoing description, contrast as can be known with networking shown in Fig. 2, the resistance of resistance R shown in Fig. 31 is 8R (being original 8 times); The resistance of R2 is 4R; The resistance of R3 is 2R, and R4 and R5 are constant.By above-mentioned arrangement, when plug insertion socket (Jack) 4, because R1, R2, R3 be by the elastic sheet switch short circuit in the

socket

1,2,3, so the voltage distribution by R4 and R5, making the voltage of node " Read back " is VDD/2.Be inserted in the socket (Jack) 3 if plug changed, this moment, R1, R2, R4 were by the elastic sheet switch short circuit in Jack1, Jack 2 and the Jack4, so the voltage of node " Read back " can get VDD/3 via the voltage distribution of R3 and R5.Promptly produce aforementioned indivedual socket and inserted the phenomenon that occurs different situations under the plug.Even plug in simultaneously in Jack3 and Jack4, this networking also can obtain dividing potential drop node " Read back " the voltage VDD/4 of R3+R4=3R and R5, thereby distinguishable to go out be to have plugged plug in Jack3 and Jack4 simultaneously at present.

Listed the truth table of resistance in Fig. 3, listed four earphone sockets under all situations about all being inserted into according to above-mentioned principle, the voltage of node " Read back " does not all repeat.As long as this voltage sent into utilizes a simple ADC to differentiate the roughly voltage range of input in the integrated circuit, the state of four sockets outside can only judging with the pin of an integrated circuit.Subsidiary one what carry is that the allocation scheme of resistance value is an example among Fig. 3, also can use other allocation scheme instead.Even the resistance value of adjusting R5 also can improve the variable quantity of node " Read back " voltage, helps ADC and differentiates its difference.For example R5 uses 4R instead, when then Jack4 is plugged plug, the voltage of node " Read back " can become 4/5VDD from 1/2VDD, and Jack1, Jack2, when Jack3, Jack4 are plugged plug, the voltage of node " Read back " can become 4/19VDD from 1/16VDD.Have only Jack4 to be plugged plug thereby be used for differentiating, the voltage variety when all being plugged the plug both of these case with Jack1, Jack2, Jack3, Jack4 has improved about 35%.More than be elastic sheet switch to the explanation at networking among Fig. 3 at aforementioned " be the open circuit shape when having plug to insert, otherwise be short circuit ".In other words, when becoming the elastic sheet switch of operation conversely, present embodiment is still effective, and only listed resistance value need be done suitable adjustment among Fig. 3.In addition as described above, the networking shown in Fig. 3 is an embodiment with four sockets among the present invention, in theory the quantity of socket and unrestricted.In addition, networking shown in Fig. 3 is to adopt the resistance of series connection different resistance values to come dividing potential drop, to differentiate different earphone sockets.If adopt the resistance of different resistance values in parallel to shunt, still belong to design spirit of the present invention.

Fig. 4 is the embodiment of a parallel resistance shunting.Be appreciated that by circuit theory resistance R 1, R2, R3, R4 are that parallel coupled is together by the elastic sheet switch of its four earphone sockets of following respectively in this circuit.State by earphone socket determines its in parallel whether shunting, carries out dividing potential drop with the resistance R 5 of series coupled again, thereby can get the voltage of node " Read back ".

As seen from the above embodiment, under the various combination when plug insertion socket, the output at its electric resistance partial pressure or shunting networking changes situation, can find out by the truth table shown in Fig. 3, be not to be linear change, this will increase ADC distinguishes node " Read back " magnitude of voltage in the testing circuit degree of difficulty and cost.For example a system that has only four earphone sockets just has 16 kinds at most and inserts combination, but but can not adopt an ADC who has only the 4-Bit resolution; Above example, the resolution of ADC need reach 8-Bit.Can change for this reason and adopt active (Active) resistance networking to implement.

Shown in Fig. 5 a, when adopting the active networking to implement, it includes a plurality of sockets, this socket also includes elastic sheet switch and

1,2, the

3,4 of earphone socket is two signal contacts, and pin 5 is the common reference points of signal, as shown in Figure 2, but in Fig. 5, omit, and do not shown.But similar among its circuit structure and Fig. 2, its difference is that the 5th resistance R 5 is connected between first reference potential (" VDC ") and the multiple socket networking first end points N1.The first end N1 refers to the common ends of multiple socket networking first socket, first pin and corresponding resistance R 4.Include an inverting amplifier OPA in this embodiment, the first end points I N of this sign-changing amplifier OPA is connected with the above-mentioned first end N1, the second end points IP of inverting amplifier OPA and second reference potential as " " current potential is connected.The 3rd end points of this inverting amplifier OPA then is connected with the second end points N2 at multiple socket networking, and the second end N2 refers to the common ends of multiple socket networking the 4th socket second pin and corresponding resistance R 1.Measure output voltage " Read back " at the multiple socket networking second end points N2.

Wherein the purpose of DC voltage " VDC " be make among the embodiment OPA that is " inverting amplifier " configuration can produce one to be different from " " output voltage of current potential.Be appreciated that by circuit theory, the total resistance value at the resistance in series networking in last example between the IN of OPA pin and OP pin is the plug insertion combination decision by each socket, and is to be the linear changing relation between the total resistance value at combination that plug inserts and resistance networking.Different combination when therefore the output voltage " Read back " of OPA inverting amplifier also will be along with plug insertion socket and be linear change.Can only differentiate the system status of four earphone sockets thus with the ADC of 4-Bit.

Certainly Fig. 5 a is a kind of embodiment that the present invention adopts active resistance in series networking, and the similar embodiment of other same spirit also can be arranged.For example adopt active parallel resistance networking or other modes, shown in Fig. 5 b, promptly adopt an embodiment at active parallel resistance networking, resistance R 1, R2, R3, R4 are that parallel coupled is together by the elastic sheet switch of its four earphone sockets of following respectively in this circuit, and decide its in parallel whether shunting by the state of earphone socket, be connected with first end of resistance R 5 again at the common end points N 3 of above-mentioned resistance R 1, R2, R3, R4, and the OP of inverting amplifier OPA end is connected to second end of resistance R 5; The common end points N4 of above-mentioned each elastic sheet switch then is connected to first reference potential (" VDC ").The IP end of above-mentioned inverting amplifier OPA is connected to second reference potential, as " " current potential, the IN end of inverting amplifier OPA is connected to the common end points N3 of above-mentioned resistance R 1, R2, R3, R4.Measure output voltage " Read back " at second end of resistance R 5.

Wherein the purpose of DC voltage " VDC " be make the OPA that is the inverting amplifier state among this embodiment can produce one to be different from " " output voltage of current potential.Be appreciated that by circuit theory, the total resistance value at the parallel resistance networking in last example between the IN of OPA pin and OP pin is to insert combination by the plug of each socket to decide, and is the linear changing relation between the total resistance value at combination that plug inserts and resistance networking.Different combination when therefore the output voltage " Read back " of OPA inverting amplifier also will be along with plug insertion socket and be linear change.Thereby can only tell the situation of four earphone socket systems with the ADC of 4-Bit.

Though the very suitable computer system that is applied to of the embodiment among the present invention, it also can be applicable in other systems with similar demand.In addition, the present invention is to be embodiment with the earphone socket, but for the personnel that know this technology; also can be applicable in the socket of other types; therefore, every modification and similar arrangement of being done in not breaking away from design spirit of the present invention and scope all should comprise in protection scope of the present invention.

Claims

1. A network that uses a single bit to detect multiple sockets, including:

a plurality of sockets including dome switches;

A plurality of resistors, the plurality of resistors are coupled in series through the shrapnel switches of the plurality of sockets respectively followed by them, whether the series shunt is determined by the state of the plurality of sockets, the shunt switches of the plurality of sockets and the The plurality of resistors are divided and connected in parallel;

A voltage-dividing resistor, the voltage-dividing resistor and the plurality of parallel-coupled voltage-dividing resistors are then parallel-connected to divide the voltage, and the output voltage of the output node that can determine the number of plugged sockets and determine the position;

Wherein the first terminal of the network for detecting multiple sockets is connected to the first reference potential, the first terminal of the network for detecting multiple sockets refers to the first socket in the plurality of sockets and the corresponding resistor in the plurality of resistors the common end; the second terminal of the network for detecting multiple sockets is connected to the second reference potential, and the second terminal of the network for detecting multiple sockets refers to the connection between the last socket in the plurality of sockets and the corresponding resistance in the plurality of resistors common end.

2. The network using a single bit to detect multiple sockets according to claim 1, wherein the first reference potential is VDD or "ground" potential.

3. The network using a single bit to detect multiple sockets according to claim 1, wherein the second reference potential is VDD or "ground" potential.

4. The network using a single bit to detect multiple sockets according to claim 1, wherein each socket of the plurality of sockets includes a pin 1 and a pin 2 for the dome switch, Pin 3 and pin 4 are two signal contacts, and pin 5 is a common reference point for signals.

5. A network using a single bit to detect multiple sockets, comprising:

a plurality of sockets including dome switches;

A plurality of resistors, the plurality of resistors are coupled together in parallel through the first contacts of the shrapnel switches in the plurality of sockets respectively followed by them. a switch is connected in series with the plurality of resistors;

A voltage dividing resistor, which is connected in series with the plurality of series coupled voltage dividing resistors to divide the voltage, and obtains the output voltage of the output node capable of judging the number of plugged sockets and determining the position; and

Wherein the voltage dividing resistor of the network for detecting multiple sockets is connected to the first reference potential;

And the second contacts of the dome switches in the plurality of sockets are connected to the second reference potential.

6. The network using a single bit to detect multiple sockets according to claim 5, wherein the first reference potential is VDD or "ground" potential.

7. The network for detecting multiple sockets using a single bit as claimed in claim 6, wherein the second reference potential is VDD or "ground" potential.

8. The network using a single bit to detect multiple sockets according to claim 5, characterized in that: each socket of the plurality of sockets includes a pin 1 and a pin 2 which are shrapnel switches. Pin 3 and pin 4 are two signal contacts, and pin 5 is a common reference point for signals.

9. A network using a single bit to detect multiple sockets, the network adopts an active series resistor network, which includes:

a plurality of sockets including dome switches;

A plurality of resistors, the plurality of resistors are coupled in series through the shrapnel switches of the plurality of sockets respectively followed by them;

A voltage dividing resistor, the voltage dividing resistor is connected between the first reference potential and the first terminal of the network for detecting multiple sockets, the first terminal is the corresponding pin of the first socket in the network for detecting multiple sockets The common end of the resistor;

An inverting amplifier OPA, the first terminal IN of the inverting amplifier is connected to the first terminal of the above-mentioned network, the second terminal IP of the inverting amplifier is connected to the second reference potential, the first terminal of the inverting amplifier OPA The three-terminal OP is connected to the second terminal of the network, which is the common end of the second pin of the last socket in the network and the corresponding resistor, and is at the second terminal of the network Measure the output voltage.

10. The network using a single bit to detect multiple sockets according to claim 9, characterized in that: the first reference potential is to enable the inverting amplifier OPA to generate an output voltage different from the "ground" potential The DC voltage "VDC".

11. The network using a single bit to detect multiple sockets according to claim 9, wherein the second reference potential is "ground" potential.

12. The network using a single bit to detect multiple sockets according to claim 9, characterized in that: each socket of the plurality of sockets includes a pin 1 and a pin 2 which are shrapnel switches. Pin 3 and pin 4 are two signal contacts, and pin 5 is a common reference point for signals.

13. A network using a single bit to detect multiple sockets, the network adopts an active parallel resistor network, which includes:

a plurality of sockets including dome switches;

A plurality of resistors, the plurality of resistors are coupled together in parallel through the first contacts of the shrapnel switches in the plurality of sockets respectively followed by the plurality of resistors, and whether the parallel shunt is determined by the state of the plurality of sockets;

A voltage dividing resistor, the common end of the plurality of resistors is connected to the first end of the voltage dividing resistor;

An inverting amplifier OPA, the OP end of the inverting amplifier OPA is connected to the second end of the voltage dividing resistor; and

Wherein the common terminal of each shrapnel switch is connected to the first reference potential, the IP terminal of the inverting amplifier OPA is connected to the second reference potential, the IN terminal of the inverting amplifier OPA is connected to the common terminal of a plurality of resistors, and The output voltage is measured at the common terminal of each dome switch in the network.

14. The network using a single bit to detect multiple sockets according to claim 13, characterized in that: the first reference potential is to enable the inverting amplifier OPA to generate an output voltage different from the "ground" potential The DC voltage "VDC".

15. The network for detecting multiple sockets using a single bit as claimed in claim 13, wherein the second reference potential is a "ground" potential.

16. The network using a single bit to detect multiple sockets according to claim 13, characterized in that: each socket of the plurality of sockets includes a pin 1 and a pin 2 which are shrapnel switches. Pin 3 and pin 4 are two signal contacts, and pin 5 is a common reference point for signals.