DE2616975C3 - Arrangement of useful signal and control signal lines for low-coupling wiring of semiconductor switches - Google Patents

Description

is chosen. where Cl to C4 are the partial capacitances between adjacent pairs of lines (la. Ib; 2a, 2b) of the printed circuit board equipped for the operational case.

The invention relates to an arrangement of useful signal and control signal lines for low-coupling Wiring of semiconductor cladding, which is used to switch useful signals in the crossing points of a wiring

■ deadline matrix are arranged and shared with which can be operated by control signals via control signal lines, the control means controlling the semiconductor switches are combined in an integrated circuit to form a coupling module which has a housing

■ η two parallel rows of rows of pins with to has a connection window for the integrated circuit leading connection lines and on one Circuit board with two wiring levels externally encased with further coupling lines of the same type

w is.

There are numerous circuit arrangements in technology that form a network of separately operated line and column lines, whereby in the intersections of these lines mostly similar components

Vi elements are each connected to a row line and a column line. These components arranged in the form of a matrix can, for. B. diodes, semiconductor memory cells, relay contacts or transistors designed as electronic Schaller or thyristo-

M ren be. If these components are sensitive to interference Switching signals, these signals must be decoupled from interfering influences from neighboring signals will. This requirement occurs particularly when the, for example, an integrated circuit

^ summarized structure, i'jmente only part of the represent the entire .Schaltmatrix and multiple lines on a circuit board or on several Printed circuit boards with other components of the same

Ari need to be connected.

Particularly high requirements are placed on the means Switches arranged in the form of a matrix are switched through analog signal paths for voice transmission due to the requirement for a high dynamic range and set a high signal-to-noise ratio.

An aggravating secondary condition is that the semiconductor circuits are usually in so-called dual-in-line housing with two parallel Rows of connection seals are installed where a m capacitive decoupling of input and output lines not from the outset by separate, right-angled ones arranged rows of pins is possible.

From the wiring technology of electrical Devices is, for example, from the publication ι> »Flexible, printed circuits - a modern one Wiring element «from PAMPUS, page 14, Fig. 6, both low-coupling routing of unbalanced and balanced signals are known According to this, signal lines which are sensitive to interference and which are unbalanced to earth are arranged in a wiring level between lines at ground potential relocated. Signal lines balanced to ground are susceptible to interference through on both sides of the Signal lines and lines at ground potential are shielded Integrated circuits available space not be applied, so that by there closely adjacent conductor tracks consist of higher capacitive coupling possibilities from adjacent signal lines.

An arrangement of useful signal and control signal lines for wiring semiconductor switches that for switching useful signals at crossing points is are arranged in a wiring matrix and which are combined in an integrated circuit to form a coupling module with control means which can be operated by control signals via control signal lines and which control the semiconductor switches which has a housing with two parallel rows of connecting pins is from DE-AS 22 46 200 known. In this known arrangement, the object is achieved, the same attenuation values of the signals to be achieved via various transmission routes. The known arrangement, however, leaves wedges systematic Detect measures against capacitive coupling between the different useful signal lines.

Measures against capacitive coupling in a switching network are from DE-AS 23 40 414 w known. The switching network there consists of at least two interconnected via intermediate lines, each produced individually using integrated technology Coupling matrices (coupling module) contained stages and intermediate lines form together with the Switching matrices, which are connected to one another by these intermediate lines, are monolithic Block. A coherent shielding layer is provided between the intermediate lines for capacitive decoupling.

The invention is based on a state of the art as it is essentially derived from the »Scientific Reports AEG-TELEFUN KEN ", Vol. 44 (1971), H. 4. Page 165 is known. Here are the semiconductor switches of a coupling multiple with their useful signal and M Control signal lines, including control means, are combined to form a coupling module, which is a Has housing with two parallel rows of connecting pins and on a Leiiungsplatie mn two Wiring levels are connected externally with other coupling modules of the same type. These Coupling modules have the advantage that they are produced as an integrated circuit with a good yield and can be checked individually. The disadvantage, however, is that without special measures between the different useful signal lines in the coupling module and capacitive couplings on the line plate appear.

The invention is based on the object of specifying a space-saving and as clear as possible line arrangement that makes it possible. Semiconductor switches, which are arranged for switching useful signals at crossing points of a wiring matrix, Wiring without additional shielding measures in such a way that capacitive coupling of the various Nuizsignallinien are largely avoided.

In the case of a line arrangement of the type mentioned at the outset, this object is achieved by the method described in claim 1 mentioned features solved here wi.d in more advantageous Exploited the fact that there are two types of signal lines in the above-mentioned arrangement are, namely on the one hand signal lines for useful signals, for example analog signals with frequencies in the range of Hz to a few kHz, and on the other hand Signal lines for the control signals serving logic signals that occur as a result of these Switching edges essentially only contain high frequency components and DC voltages.

Due to the inventive arrangement of the semiconductor switches and their control means on the integrated circuit, the pads of the useful signal and control signal lines are at the edge of the integrated circuit and have an alternating sequence. This allows the external connecting lines from the integrated circuit to the Lead the connecting pins of the coupling module, lay them without crossing so that a control signal line leads between each two adjacent useful signal lines come to lie. If care is now taken that the control signal lines, which are by means of two-level Signals that switch the semiconductor switches on and off, in the two stable logic states of their signals at least for frequencies in the transmission range of the Useful signals are connected to ground with low resistance, the control signal lines act like shielding lines and complex additional shielding lines can be saved.

The individual coupling modules are in a known manner on a circuit board with two Wiring levels connected externally with further coupling modules of the same type. A further education The d-T invention now sees multiple wiring with transverse on one wiring level of the circuit board to the rows of pins running Lewerbahnen, in which the useful signal lines run parallel and are separated by control signal lines running therebetween. On the other wiring level the printed circuit board is a similar multiple wiring system with parallel to the terminals running conductor tracks are provided. In this way, the advantage of the alternating conductor track routing between useful signal lines and control signal lines is also used on the circuit board. Are the input lines of the semiconductor switch on one wiring level and on the other The wiring level, the external lines of the semi-

assigned to a conductor switch, a clear, low-coupling ratio is obtained in spite of the compact conductor arrangement Wiring.

If the semiconductor switches of the coupling modules are intended to switch useful signals balanced to ground, capacitive coupling of the two lines of a line pair is not critical, since this coupling can only influence the linear frequency response of the useful signals, but does not lead to interference in neighboring line pairs. Therefore, in the case of useful signals balanced to ground, it is in each case a line pair consisting of two lines a and b . especially in the case of a pair of voice wires in a switching network. Convenient to arrange the pads of each type a of the line pair on one side of the integrated circuit and the corresponding pads of the other line b of the line pair on the opposite side of the one side of the integrated circuit, opposing pins of the two rows of pins of a coupling module each to connect to a pair of lines and to separate pins of an adjacent pair of lines by intermediate pins connected to control signal lines. This measure is also used for clear wiring and saves additional shielding measures.

The same advantages are achieved with the wiring planes of the printed circuit boards for the case of useful signals symmetrical to ground in that in the multiple wiring the respective lines a and b of a line pair run directly next to one another.

As a rule, multi-pole connecting plugs are provided on one side of the printed circuit board provided with the multiple wiring. A further development of the invention now provides that. If the circuit board has multi-pole, two-row connector plugs on one side, the respective line pairs on the circuit board must be connected without crossing with the connector pins of the connector, in such a way that the respective line pairs are connected to opposing SicvkciMificii sniu umi iwisuiieri Sieckersuf ten adjacent line pairs each two connected to control signal lines Connector pins lie. If the wiring diagram is clear and consistently adhered to, this measure also keeps the capacitive coupling of the useful signal lines including the plug connection low.

However, the planar arrangement of the useful signal lines in the coupling module and on the Wiring levels of the printed circuit board have different partial capacities between the conductors of adjacent ones Useful signal line pairs. In order to compensate for this capacitive coupling, it is in the case of the invention Arrangement of useful signal lines and control signal lines possible in a simple manner, additional capacities to be provided between the two outermost conductors of two adjacent pairs of lines, whose Values according to the one equipped for the operational case Align the circuit board.

The invention will now be based on exemplary embodiments, in particular an exemplary embodiment for Useful signals balanced to the ground, such as those used, for example, as voice signals in switching networks of exchanges are switched, explained in more detail. It is time

F i g. I arrangement of the connection surfaces of an integrated circuit of a coupling module,

F i g. 2 Top view of a housing of a coupling module for receiving an integrated circuit Assignment of the connection pins.

F i g. 3 Multiple wiring of the input lines on one wiring level of the circuit board.

Fig. 4 Multiple wiring of the output lines on the other wiring level of the circuit board,

F i g. 5 Line arrangement on the printed circuit board with a multi-pole connector.

F i g. 6 Equivalent circuit diagram for the capacitive coupling

Hi gene of adjacent pairs of conductors.

In Fig. I is an arrangement of to be contacted Curses (connecting surfaces) of an integrated formwork a coupling arrangement shown. The integrated circuit does not contain a large number of here

ι · shown semiconductor switches that are used to switch Useful signals at crossing points of a wiring matrix are arranged and jointly beireibbaren by control signals via control signal lines. the semiconductor switches controlling Ansteucrmiitcl to

> are combined in a coupling module.

Fig. 1 shows contact surfaces FAa.Ela /: 5a on the left

for the input lines of a-cores, contact surfaces E \ b on the right. £ 26 £ 56 for the F. input lines

of 6 cores above two first contact surfaces A la and

: ■> A \ b for the output lines of a first output wire pair and below two further contact surfaces A 2a and A 2b for the output lines of a second output wire pair. All of these mentioned connection surfaces lead more or less sensitive to interference

jo signals.

In addition to the useful signal connection areas, connection areas St i. St 2 Sf 12 arranged for the control signal lines of the control means which actuate the semiconductor switches. According to an inventive

ii according feature are the semiconductor switches and the control means assigned to them are arranged on the integrated circuit in such a way that the Connection surfaces (contact surfaces) of the useful and control signal lines on the edge of the integrated switch

4Ii direction lie and have an alternating order. This alternating sequence has the gruueri advantage that the external circuitry can now be routed in such a way that between two adjacent interference-sensitive circuits

4i useful signal lines each have a control signal line come to lie. This is explained in more detail below.

As Fig. 2a shows, the integrated circuit in a housing 5 with two parallel rows 41 and 42 of connecting pins installed (dual-in-line housing).

The connection pins are connected to the connection areas of a connection window 11 by means of connecting lines 3 which are free from crossing, in which the semiconductor chip 1 with the integrated circuit and with the connection area arrangement according to FIG. 1 is used. The connection surfaces of the integrated circuit are connected to the connecting lines 3 without crossing via thin bonding wires 2.

F i g. 2b now shows a first embodiment of a conductor arrangement according to the invention for the connecting lines. The connecting lines in the housing are laid as shown in Fig. 2a. Adjacent Connecting lines 3 in the housing have coupling capacitances of about I pF, which is too inadmissible high capacitive coupling of neighboring useful signals would result if useful signal lines there with different useful signals would lie.

Since the coupling capacitances within the

integrated circuit can be kept very small even with high packing density, predominate in a conventional wiring arrangement, the coupling capacitances between the connecting lines of the Housing.

The connection assignment according to the invention now achieves a considerable improvement in the decoupling of connecting lines that are sensitive to interference. For this purpose, the connecting lines 3 are switched in such a way that the useful signal lines 51, 52, 59 in the two rows of pins 41 and 42 are separated by control signal lines 5/1, St 2 5/9. This yourself

The resulting line arrangement for the connecting lines in the housing and the further wiring outside the housing is for example for Useful signals unbalanced to earth are favorable. If it is ensured in the circuits processing the control signals that the control signal lines are in the stable logical states of their signals at least for frequencies in the transmission range of the useful signal lines compared to the alternating current resistance of the Coupling capacitances are connected to ground with low resistance, then these measures can make the Capacity and thus the coupling between the useful signal lines by a factor of 50 to 100 be reduced.

In the case of useful signals balanced to ground, which are routed in line pairs consisting of two lines a and b , as is the case, for example, with a speaking pair of a switching network of a telephone exchange, the outward and return lines of a line pair do not interfere with each other and can therefore be on one PCB are laid next to each other. With a view to multiple wiring of the usually numerous useful signal inputs, the connecting lines of which run across the rows of pins, and the useful signal outputs, the connecting lines of which run parallel to the rows of pins, the pin assignment of the integrated circuit was chosen in the order given. This now makes it possible to arrange a control signal or an operating voltage line between interfering useful signal lines minücMcii ». Even if the control signal lines briefly carry pulse signals in the event of logical signal transitions, they act like earthed shielding lines due to their low alternating current resistance to ground, so that the partial capacitances between adjacent pairs of lines are reduced by a factor of more than 10. This improvement applies both to the connecting lines including the connecting pins of the housing and to the much more extensive line routing on the circuit board in which the coupling modules are used. The alternating arrangement of useful signal lines and control signal lines also advantageously prevents leakage currents between adjacent useful signal lines, which could otherwise cause considerable galvanic coupling.

As Fig. 1 and Fig.2c show, in the case of useful signals balanced to ground, the pads of each line a of the pair of lines are on one side of the integrated circuit, in the exemplary embodiment on the left, and the corresponding pads of the other line b of the line. gspsares on the side opposite the one side of the integrated circuit, that is to say on the right side in the exemplary embodiment, are arranged opposite pins of the rows of connecting pins 41 and 42 of the housing are each connected to a pair of lines. So are z. B. the inputs of the first pair of lines E 1 a and E 1 b with the pins labeled in the same way (Fig. 2c) verbun-ί the. Via the connecting lines shown in FIG. 2a, this first line pair is connected by means of the bonding wires to the connection surfaces E 1 a and E 1 b on opposite sides of the integrated circuit shown in FIG. The same goes for that

m output lines of the first line pair A \ a and A 16 etc.

Furthermore, F i g. 2c it can be seen that the connection pins of an adjacent pair of lines, for example (A la, A 1 b) and (EIa, ElW, are located in between.

π pins connected to control signal lines (St i and 5/2) are separated.

The coupling modules switched internally in this way can now be combined in an optimal way Koppeibausieiiieii the same, Ar! interconnect For this purpose, the coupling modules are used in a printed circuit board with two wiring levels. A conductor arrangement according to the invention for the one wiring level of the circuit board with housings inserted 51 to 54 of the coupling modules is shown in FIG. 3 shown.

α At this level, the circuit board is provided with transverse to the rows of terminal pins conductor tracks provided a multiple wiring, wherein the Nutzsignalleitungen are parallel and separated by intervening running control signal lines.

in In F i g. 3 and the subsequent F i g. 4 and 5, only a part E \ to E3 of the input terminal pairs E \ to £ "5 is shown for a better overview of the line arrangement

> s useful signals instead of a useful signal line pair, only one useful signal line has to be laid.

Due to the mirror-image to the housing axis assignment of the a and b wires as shown in Figure 2c can be an immediate neighboring routing of a and b Cores with less than 13 mm spacing realize the are separated from neighboring wire pairs by at least one oKti-mrinpnrfp connector.

On this circuit board level is also that of a control signal line, in the embodiment shown Example 5/7 surrounding useful signal line A 2a of an output line is arranged, which leads to a via point 6 /. The via point 6 / belongs to the useful signal line A 3a of the housing 5 /, where ι in the embodiment shown equals 1. 2, 3 and 4. This somewhat unusual routing of the output signal line A 2a shown in FIG. 3 has the advantage that it is a particularly space-saving ver on the back of the circuit board, that is to say on the other wiring level wiring allowed

F i g. 4 shows the multiple wiring of the outputs of the useful signal lines on the other wiring level of the circuit board with the same viewing direction as at Fig.3, so that there is no reversal of the The output lines of the useful signal line pairs A 1 and A 3 of the odd useful signal line pairs, for example, are multiple-switched under the housings and the output lines A 2 and A 4 of the even useful signal, for example In addition to the housings, there are many signal lines switches The multiple wiring of this level is similar to that of the wiring level described above, but the conductor tracks run here

parallel to the rows of connecting pins. Only that .Control signal lines Sf I and Sf 8 are meandering and partially routed in two ways to the output signal lines that are under the housings run, not to cross over and they / u decouple. .

The line formation of the output signal lines A ϊά the in F i g. The wiring level shown in FIG. 3 is shown in dashed lines in FIG. These lines cross the neighboring output signal line pairs which run under the housings between the rows of connection slits and are connected at the through-hole contact point 61 or 62 to the useful signal lines assigned to them a of the output signal line pairs running between the housings.

This special routing of the A2a lines advantageously enables multiple wiring under the housings so that the coupling components can be wired more economically and without mutual interference through capacitive coupling.

In Fig. 5 shows how the wiring of FIG. J and F i g. 4 to the plug connections 71 and 72 for the input signal line pairs and 73 for the output Useful signal line pairs of the circuit board is guided without the principle of decoupling by control signal lines to hurt. The conductor tracks of one wiring level (Fig. 3) are thick here Lines, the conductor tracks of the other wiring level (FIG. 4) represented by thin lines. The Fig. 5 shows the two wiring levels in one picture and also various options for routing cables for the control signal lines within the scope of the invention.

The plug connections are shown schematically and drawn as a direct plug connection on the circuit board in section through the plate. It can thus be seen that the shading of the connections is carried out in such a way that the respective pairs of lines that belong together on the circuit board are connected to the connector pins of the connector without crossing; iitvl P ^ip jpwpil «7i. Line pairs belonging to a group are connected to mutually opposite connector pins. Furthermore, connector pins of adjacent line pairs are separated by connector pins connected to control signal lines. This theoretically guarantees complete decoupling in the connector as well.

In Fig. 5 are the remaining vias of the Lines that do not contribute to the understanding of the invention are not shown. These vias are sometimes required in the vicinity of the connecting plugs because of multiple wiring on both sides the input lines of the useful signal lines z. B. only on one wiring level (FIG. 3) and the output lines of the useful signals are only on the other wiring level (FIG. 4).

Of course, it is not enough to just consider the cable routing of a wiring level in isolation and assess it as sufficiently decoupled. The circuit board is, for example, 1.5 mm thick, that is, a little thicker than the line spacing of a and b wires that belong together. However, the dielectric constant of a circuit board is relatively high on the order of E = 6. Therefore, capacitive coupling also occurs through the circuit board.

In Fig. 6a is an equivalent circuit diagram of the partial capacities

between two adjacent pairs of lines (la, ib)

; and (2a, 2b) are shown for a general perspective. The effective capacitance for coupling the two pairs of lines is

Cuts a straight input line la on one wiring level of the

a parallel output line pair (2a, 2b) in the printed circuit board on the other wiring level of the conductor pairs, this creates capacitance components C1 and C3 of the same size, which cancel each other out according to equation I. The same applies to an input line ib which is a parallel

π output line pair intersects. In this case too, the capacity shares C2 and CA cancel each other out. Complete crossovers are therefore not dangerous.

never capacitive coupling of conductor tracks in the

2i) level is in F i g. 6b. The effective capacitance of parallel line pairs (la, Xb) and (2a, 2b) with a control signal line in between cannot be completely compensated in principle without additional measures, since the difference between the partial capacitances C1 and C4 is greater than the difference between the partial capacitances of C2 and C3. The remaining effective capacitance Cn- is, however, much smaller than an individual capacitance of the partial capacitances Cl to C4 and decreases considerably with the number of shielding lines between the line pairs.

A complete decoupling of two adjacent pairs of lines can be achieved by an additional capacitance Cz , which can be used as a compact capacitor, as a trimmer or as a flat element on the printed circuit board

) i can be realized and their size

is. The residual coupling between adjacent pairs of lines can thus be reduced by at least a factor of 10. This advantageous compensation of the remaining residual capacitance cannot be effectively carried out without the line arrangement according to the invention, because if the Cw is too high, the compensation depends too much on the long-term constancy of the partial capacities. On a stcckbaiciV printed circuit board of the format 160x225 mm ^J (double European

* ϊ card) decoupling of 130db at 6.4 kHz can be implemented through additional capacities.

The additional capacities Cz are in Fi g. 5 shown as surface elements 81 to 84. Since printed circuit boards have different numbers depending on the intended use

μ can be equipped with coupling modules and / or connectors, the required additional capacities Cz are expediently dimensioned for the respective operating case. The additional capacitances can also be used to compensate, among other things, component tolerances, the temperature dependency of the dielectric constant of the circuit board or the capacitances in the semiconductor. The coupling of not directly adjacent pairs of lines is so small in the line arrangement according to the invention that it is practically undetectable. B. 91 to 94 effectively decouple in a simple manner.

Q ^: about 5 sheets of drawings

Claims (6)

Patent claims: 1. Arrangement of useful signal and control signal lines for the low-coupling wiring of semiconductor cladding, which are arranged for switching useful signals at crossing points of a wiring matrix and which are combined with control means which can be operated by control signals via control signal lines and which control the semiconductor switches in an integrated circuit to form a coupling module, which has a housing with two parallel rows of connection pins with connecting lines leading to a connection window for the integrated circuit and is connected externally to further coupling modules of the same type on a printed circuit board with two wiring levels, characterized in that the semiconductor switches usil the control messages assigned to them are arranged on the integrated circuit in such a way that the connection surfaces (contact surfaces) of the useful signal lines (EIa. £ 16, ..., Aia, Aib, ...) and control signal lines (SfI, St2, ...) lie at the edge of the integrated circuit of the coupling module and have an alternating order that the connecting surfaces are connected to the connecting lines (3) without crossing and that the control signal lines (StI, St 2, ...) are in the stable logic states of their signals at least for overcoupling currents at frequencies in the transmission range of the Nutzsignalleitungcn low-olimig rr.ii are connected to ground. 2. Arrangement according to claim, characterized in that on the one wiring level (FIG. 3) of the circuit board a multiple wiring is provided with transverse to the rows of pins running conductor tracks, in which the useful signal lines (Ei, E2, ...) run parallel and through control signal lines (5 (3, 5 (4 ....)) running in between are separated and that on the other wiring level (FIG. 4) of the circuit board a similar multiple wiring with conductor tracks (Λ 1, / t 2 Si 1.5 (8) is provided. 3. Arrangement according to claim I for the case of useful signals balanced to ground in each case a line pair consisting of two lines (a, b) , in particular a pair of speech wires of a Koppclfcldcs, characterized in that the connection surfaces of each line (a) of the line pair (a. B) on one side of the integrated circuit (FIG. 1: Eia, EIa, ..., £ 5aj and the corresponding connection surfaces of the respective other line (b) of the line pair (a, b) on the side opposite one of the ropes of the integrated circuit ( FIG. I: Eib, EIb, ..., Eib) are arranged mutually opposite pins of the terminal * sliflreihen each mil a pair of lines (FIG. 2c: / 4 1a, Aib, Eia, Eib ,.) are connected and terminal pins of a adjacent pair of lines (FIG. 2c: / Ils, Aib, Eia, Eib, ...) are separated by intermediate pins (Sf 2, ...) connected to control signal lines. 4. Arrangement according to claim 2 for the case of earth-symmetrical groove / signals in each one of two lines (a, b) existing line pair. in particular a pair of voice wires in a switching network, characterized in that, in the case of the multiple wiring, the respective lines (a, b) of a line pair run directly next to one another (FIGS. 3 and 4). 5. Arrangement according to claim 4 with multi-pole, two-row connecting sockets (FIG. 5: 71, 72, 73) on one side of the circuit board, characterized in that the respective pairs of lines (a, b) on the circuit board without crossing with the pins of the connector ( 71, 72, 73) are connected in such a way that the respective line pairs (a, b) with opposite one another Connector pins (bEia, bE2a ) are connected and between the connector pins of adjacent line pairs (bEia, bE2a ) there are two connector pins connected to control signal lines (Sr 4. Sf 3). 6. Arrangement according to claim 4 or 5, characterized in that for the capacitive compensation of adjacent pairs of lines (la _r 16; 2a, 2b) an additional capacitance (C /) between the two outermost conductors (la. 2b) of two pairs of lines (la. 16; 2a, 2b) is provided, the size of which (FIG. 6b)