CH615296A5 - Integrated driver component with bipolar transistors - Google Patents

Description

The invention relates to the power supply of the output stage of an integrated module, namely with an output stage made of bipolar transistors. It is an integrated driver module with bipolar transistors. The block is used in particular to control relays, e.g. B. polarized, such as bipolar telephone relays that have a well-defined response threshold. The block is suitable

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however also for controlling non-polarized relays or for controlling other devices which have to be controlled with high-energy pulses of one or both polarities, the amplitude of which should be as independent as possible of the voltage of the direct current supply.

Integrated driver modules with bipolar transistors are known in large numbers. For example, in US Pat. No. 3,435,295 and in DT-OS 2,322,639, FIGS. 1 to 4, such integrated driver modules with bipolar transistors are shown, which are used to control relays.

Three-state outputs, usually called tri-state outputs in the technical field, i.e. outputs with two different low-resistance and a very high-resistance state, are often used, cf. e.g. B. Motorola, McMOS Handbook, Oct. 1973, pages 6.20 / 6.21.

An integrated driver module with bipolar transistors is already known from Blomeyer-Bartenstein, microprocessor and microcomputer, Siemens, p. 29, figure 7c, which shows an output push-pull amplifier with two series-controlled, separately controllable push-pull transistors, this output push-pull amplifier having a three-state output . In the high-resistance state of the output, both push-pull transistors are non-conductive; in the two low-resistance states, one or the other of the two push-pull transistors is conductive. This driver module is used in particular to control other TTL circuits via bus lines.

Integrated modules, also the last-mentioned integrated driver module, can normally be supplied with DC supply voltages, which can already have a relatively large tolerance.

DT-OS 2 237 559 discloses a constant voltage source as a supply source for an integrated module. In addition to a series connection of zener diodes, the constant voltage source also contains a multi-collector transistor for supplying this series connection.

DT-OS 2 256 640 discloses a constant current source for direct current supply to an integrated module with bipolar transistors. This constant current source contains a multi-collector transistor, the collectors of which can supply a constant current. So that this current is constant, there is a further transistor in series with the emitter of this multi-collector transistor, the resistance of its collector-emitter path is controlled by a further control amplifier, the control amplifier in turn being controlled by the current in one of the collectors of the multi-collector transistor.

By z. B. Electronic Engg., Sept. 1953, pp. 358-364, esp. Fig. 4 and 13 it is known that the collector-emitter current of saturated transistors depends on the base current, but almost not on the collector-emitter voltage . The object of the invention is to greatly increase the tolerance of the DC supply voltages of a driver module, that is to say to produce a module with a so-called giant tolerance, although output currents of both polarities are to occur at the module output with relatively narrow tolerances. Because of this special task, the driver module integrated according to the invention is particularly suitable for controlling polarized telephone relays which have at least three different switching states, depending on the size and polarity of the output current, the DC supply voltages used in the system, here the ones in the telephone system, for example, one Tolerance between 36 V and 6.8 V. The tolerance of the DC power supply voltage is therefore a multiple of the minimum necessary DC power supply voltage. The driver module with such a huge tolerance of its DC power supply can therefore be extremely versatile in systems

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are used, which may largely have any supply voltages. In particular, the driver module according to the invention should, however, additionally allow the control of unpolarized relays at particularly low DC supply voltages of the driver module, i.e. relays with two switching states, which in their first switching state by output currents with a certain minimum magnitude of one polarity and by output currents below one second minimum size of the same polarity io can be controlled in the second switching state; In order to prevent driver module output currents from flowing in the absence of control signals, which load the output stage of the driver module and the organ connected to the driver module output, in particular polarized relays, with a quiescent current, the driver module output must also be able to be controlled in a high-impedance state; a three-state output should therefore be provided.

The invention is based on an integrated driver module with bipolar transistors as well as with an output clock amplifier, which is formed by two series-controlled, separately controllable push-pull transistors, the output push-pull amplifier having a three-state output. The driver module according to the invention is characterized in that each of the two push-pull transistors 25 of the output push-pull amplifier is driven via a constant current source that is only switched to supply current when the push-pull transistor in question is controlled in its conductive state. As such, a constant current source of its own can be attached 30 for each push-pull transistor. Both push-pull transistors can also by a common constant current source, z. B. be controlled by a single multi-collector transistor, the first collector of which supplies the base current for the first push-pull transistor and the second collector of which is the base current of the 35 second push-pull transistor, switches, e.g. B. transistor switch, once the constant current to the first, later the second push-pull transistor. Such switches are to be inserted in particular between the constant current source and the control electrodes of the push-pull transistors. The invention and further developments thereof are explained in more detail with reference to the exemplary embodiments shown in FIGS. 1 to 3, wherein

Fig. 1 shows the principle of an embodiment and

FIGS. 2 and 3 show detailed exemplary embodiments for the principle shown in FIG. 1.

The basic circuit diagram shown in FIG. 1 shows the signal input I for the polarity control signal which controls the polarity of the current at the driver module output Q. In addition, the activation signal input EN, in the technical field mostly called Enaso signal input, is shown, via which the driver block output Q can be controlled either in its high-resistance (EN = L) or in a low-resistance state (EN = H). The relay RE connected to the driver module output Q, here polarized, is thus flowed through by currents of one or the opposite polarity in the low-resistance state 55 of the output Q, depending on whether the polarity control signal I is L or H in each case. However, no current flows through the relay RE if the driver module output Q has a high impedance, that is to say if there is no activation signal at the activation signal input EN, ie EN = L.

In the driver module shown in FIG. 1, there is therefore an output push-pull amplifier with two,

separately controllable, bipolar push-pull transistors, whose output Q forms a three-state output. 65 Depending on whether

1. both push-pull transistors A1 / A2 are in their blocking state, or whether

2. the one or

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3. the other of these two push-pull transistors, ie AI or A2, is in its conductive state,

flows through the polarized relay RE

1. no electricity, or a current

2. the one or

3. different polarity.

The output current of the first polarity flowing through the relay RE thus flows via the direct current supply connection USI, via the push-pull transistor A2, via the output Q and via the relay RE to the connection UM. The output current of opposite polarity, on the other hand, flows to the DC supply connection US2 via the push-pull transistor AI, via the output Q and via the relay RE from the connection UM.

As shown in Fig. 1, the potentials at USI, e.g. B. + 15 V, and at connection US2, z. B. -15 V. However, it was shown, as will be described later, that these potentials are also very considerable, e.g. B. each can deviate downwards by a factor of 2, although the output currents through the RE element have an almost constant amplitude - that is, huge tolerances are permitted for the direct current supply.

In this example, each of the two push-pull transistors A1, A2 is controlled via its own constant current source S1, S2. The individually assigned constant current source SI, S2 is in turn switched to its current-supplying state when the associated push-pull transistor AI or A2 to be controlled by it is to be controlled in its conductive state. As long as the associated push-pull transistor A1, A2 is to be controlled in its non-conductive state, however, the relevant constant current source S1 or S2 is also not switched to the state in which this constant current source has a current for controlling the assigned output transistor AI or A2 in it supplies conductive state.

Because the two push-pull transistors A1, A2 can be controlled separately, that is to say can be controlled independently of one another in their conductive or non-conductive state, the driver module output Q forms a three-state output. The fact that the two separately controllable push-pull transistors A1, A2 are only controlled with stabilized currents, that is to say largely independent of the direct current supply, via individually assigned, that is, their own constant current sources SI, S2, means that the supply voltage at the connections USI, US2 can not only have huge tolerances, instead, each of the two constant current sources SI, S2 itself can optionally be switched in its current-supplying and non-current-supplying state without having to install additional switches between these constant current sources and their associated push-pull transistors. Because of the huge tolerance, a stabilized, predetermined current of the constant current sources SI, S2 can control the bipolar push-pull transistors Al, A2 practically independent of the respective size of the DC supply voltage only in those conductive states in which the collector current or emitter current of these push-pull transistors Al, A2 over - one the amplification factor of these output transistors, well-dependent on the stabilized current of the constant current sources SI, S2 - output current provides the organ connected to the driver block output Q, here a bipolarized relay RE. This is particularly the case if the push-pull transistors are each controlled in their saturated state if they are to be conductive. Saturated transistors are traversed by collector currents that are almost independent of the collector-emitter voltage of this transistor.

The invention thus makes use of the fact that bipolar push-pull transistors Al, A2, which can be controlled independently of one another, can be controlled by control at their bases with currents supplied by constant current sources SI, S2 in conductive states in which these push-pull transistors are largely independent of the DC supply voltages USI, US2 and only have output currents deliver correspondingly narrow tolerances by the RE element connected to the driver module output Q.

In Fig. 1, a logic circuit V is additionally shown, which the already mentioned inputs I and EN,

and has two outputs. In this example, the first output switches the constant current source S1. The second output switches the constant current source S2. The structure of the logic circuit V ensures that the driver module output Q, that is to say the three-state output attached there, can be controlled in its three different states with the aid of control signals supplied to the driver module, here I and EN.

To further increase the huge tolerance for the direct current supply voltages, it can be provided, as indicated in FIG. 1, that the logic circuit V itself is also supplied with direct current via a voltage-stabilizing and / or current-stabilizing, additional stabilizing unit S3. As a result, each of the constant current sources SI, S2 can be switched with specially stabilized signals via the outputs of the logic circuit V, so that the outputs of the constant current sources SI, S2 in turn deliver very particularly stabilized currents for driving the push-pull transistors A1, A2.

In principle, the output Q of the driver module could also represent a three-state output in that another switch or transistor, e.g. B. between the terminal RE connected to the output Q and the connection point between the push-pull transistors A1, A2. This inserted switch could e.g. B. can be controlled directly by the activation signal EN. In this case, a logic circuit V with its own activation signal input EN could be omitted.

The insertion of such a switch can be avoided if a logic circuit V controlled by an activation signal EN is provided, which directly connects the connection between the constant current sources and the push-pull transistors or which directly switch the constant current sources, so that neither of the two push-pull transistors is controlled in its conductive state and so that the three-state output Q becomes high-resistance as long as no activation signal EN is present at the driver module.

Because the constant current sources S1, S2 controlled by the logic circuit are inserted between the logic circuit and the control lines of the push-pull transistors, the push-pull transistors are controlled directly by the constant current sources and only indirectly by the logic circuit, as a result of which the stabilized control currents supplied to the bases of the push-pull transistors A1, A2 are stabilized even better than if the logic circuit acted directly on the connection between the constant current sources SI, S2 on the one hand and the associated push-pull transistors A1, A2.

The fact that the logic circuit has two separate inputs, which, as shown in FIG. 1, are supplied with the output current polarity signal I and the activation signal EN, and has two separate outputs, which directly or indirectly control the push-pull transistors, can be used in a simple manner the binary signals I and EN separate control of the two push-pull transistors and thus the desired, optional control of the state of the three-state output Q can be achieved.

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In the example shown in FIG. 1, this logic circuit is therefore inserted between the signal inputs 1 and EN of the driver module on the one hand and the two push-pull transistors and their constant current sources SI, S2 on the other hand.

As already mentioned, it can be provided that the constant current sources SI, S2 are supplied with highly stabilized switching currents by the logic circuit having a further constant source, e.g. B. another constant current source that stabilizes these switching currents of the outputs of the logic circuit. As a result, the driver module is particularly insensitive to changes in the DC supply voltages USI, US2, even though the output currents supplied to the device RE have narrow tolerances.

The switched constant current sources SI, S2 and / or the further constant source S3 can each be formed by multi-collector transistors, with at least the basis of switched constant current sources, here SI, S2, being supplied with a stabilized direct current controlled depending on the output current polarity signal I. The collectors then deliver the stabilized currents. An example of this is shown in FIG. 2. The multi-collector transistors SI, S2, here formed by integrated, lateral pnp transistors T9, T10, TI 1 and T12, T13, T14, each represent the constant current sources S2 and Sl. The path between the collector and the base of the parts TI 1 and T12 of both multicollector transistors are bridged, so that the transistors T15, T16 contained in the logic circuit V and switching the constant current sources each feed the switching currents directly into the base of the multicollector transistors SI, S2. The emitters of both multi-collector transistors are each connected to one another and are at the USI potential in the exemplary embodiment shown. The transistors T15, T16 thus control the collector currents of the two collectors of each of the transistors SI, S2, the first collector in each case, cf. T10 and T13, supplies the stabilized direct current to its associated push-pull transistors A2, AI and T20, T23, respectively. An advantage of a multi-collector transistor compared to several individual, separate transistors as a constant current source with several outputs is that, due to reduced manufacturing tolerances, the stabilized currents supplied by the various outputs of the multi-collector can be made relatively easily almost the same, i.e. that then Stabilization is particularly great. The push-pull transistors themselves are constructed here as Darlington amplifiers T19 / T20.T22 / T23 by means of npn transistors, so that the stabilized currents to be supplied by the collectors of the multicollector transistors SI, S2 can be low.

The first collector of the multi-collector transistors SI, S2 can each be connected to the control connection of the associated push-pull transistors T20, T23, or T19, T22. The second collector of these multi-collector transistors can in each case be connected to the control connection of a blocking switch K2, K1, which in each case does not control the assigned push-pull transistor, but rather the other push-pull transistor, namely releases or blocks it. These blocking switches are intended to supply an additional blocking potential to this controlled push-pull transistor during the reversal of the push-pull transistor controlled by it from the conductive to the non-conductive state, so that the reversal is accelerated. These blocking switches K1, K2 are also indicated in FIG. 1.

In the example shown in FIG. 2, the blocking switch K1, K2 is thus mounted such that it is itself conductive when the controlled push-pull transistor is to be controlled in the non-conductive state, and vice versa. Since a bipolar, especially a saturated bipolar transistor can be controlled relatively quickly in its conductive state, but only relatively slowly from the conductive to the non-conductive state, the blocking switch K1, K2 thus switched becomes the controlled push-pull transistor T23 / 20 in it Control the non-conductive state, because the blocking switch Kl, K2 or T24 / T21 itself is particularly quickly controlled in the conductive state and thus very quickly eliminates the flooding of the base of the push-pull transistor with charges and thus particularly quickly a blocking potential to the control electrode of the controlled push-pull transistor delivers. In addition, it is thereby achieved that, when switching over, both push-pull transistors T20 / T23 are never conductive at the same time, which could destroy them.

In the example shown in FIGS. 2 and 3, the logic circuit is essentially formed by a differential amplifier, which in turn can supply a relatively constant current to the bases of the multi-collector transistors SI, S2. This is particularly easily possible if the transistor T18 mounted in the collector branch of the differential amplifier is controlled into the saturation state and the resistor R6 is high-impedance, that is to say e.g. B. is approximately 15 kOhm and if the reference voltage supplied to the differential amplifier, cf. D7 represents a constant reference potential for the transistor T16 of the differential amplifier - the above-mentioned further constant source S3 enables the differential amplifier T15 / T16 to deliver particularly well stabilized switching currents to the bases of the multi-collector transistors or constant current sources S1, S2.

In particular, the circuit example shown in FIG. 3 has proven itself for the production of an integrated driver module. 2 and 3 differ in that, in FIG. 3, additional resistances R7 to R14 have been added to the push-pull transistors A1, A2, the blocking switches K1, K2 and the constant current sources SI, S2, which provide even better stabilization of the characteristic curves of the transistors in question and above all allow faster control of the transistors in question in the blocked state. In the example shown in FIG. 3, the further constant source S3 is likewise formed by a multi-collector transistor, which is controlled by a reference voltage source RV. This is because a first comparison voltage arises at the zener diode D3, which stabilizes the voltage across the voltage divider R2 / R3. The potential controlling the transistor T2 or its control current is therefore stabilized, so that this transistor T2 impresses a highly stabilized current on the base of the multi-collector transistor S3. Two collectors of the multicollector transistor S3 forming the further constant source are connected to the control electrodes of the differential amplifier T15 / T16, so that these control electrodes are operated with stabilized currents. In addition, collectors of the multi-collector transistor S3 are connected to the control electrodes of transistors T17, T18, which control and additionally stabilize the state of the transistor T18 depending on the activation signal EN, so that the transistor T18 can take on two stabilized states defined by the activation signal EN, namely one well-defined saturated and a non-conductive state. In order to promote stabilization, the logic circuit V additionally contains the transistor T1 as a preamplifier and the zener diode D4 which serves the same purpose.

When I = H, the diode D5 derives the constant current of the T6 via D7 to the ground connection E of the driver module. The diode D5 thus limits the voltage rise at the base of T15 and prevents the saturation of T15 and a possible base-emitter breakdown of T16. The diode D5 thus causes a constant potential at the base of T15 at I = H and thus a constant impressing current at the base of the multicollector transistor S3.

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It has been shown that the example shown in FIG. 3 can even be operated with 36 V between USI and US2, namely with + 18 V at USI and -18 V at US2, because of the huge tolerance achieved by the stabilizations. However, this same example can also be operated with 13.6 V between USI and US2, namely with only 6.8 V at USI and with —6.8 V at US2, without significantly influencing the output current through the organ RE.

Because the push-pull transistors Al, A2 are protected against voltages by diodes D9, D8, relays can also be connected as organs RE to the output Q of the driver module. This is because high voltage peaks occurring at the output Q when the relay is switched off are kept away from the push-pull transistors A1, A2.

The driver module shown in Fig. 3 can even be operated with DC supply voltages down to 6.8 V without interference due to the huge tolerance achieved and deliver the predetermined, closely tolerated DC current at the output Q to the organ RE if the organ RE only with output currents of the one Polarity, i.e. not to be controlled with output currents of both polarities. The organ RE can then, for. B. be an unpolarized relay. In this case, earth connection E can be short-circuited to connection US2. If there is then no activation signal EN, the output Q is in its high-impedance state because T18 is non-conductive and therefore also the multi-collector transistors SI, S2 are non-conductive, so that both the push-pull transistor A2 and the push-pull transistor AI are non-conductive.

If, on the other hand, an activation signal EN is present, depending on the output current polarity signal I, either T16 or T15 and thus either S1 or S2 is conductive, so that either AI or A2 is conductive. If the push-pull transistor AI is conductive, practically no output current flows through the organ RE connected to the output Q if earth potential is present at the connection UM. However, if the push-pull transistor A2 is conductive, an output current flows through the element RE, with a narrow, predetermined tolerance, even if the voltage between the connections UM and USI and between E and USI is only 6.8 V each - corresponding to the approximately similarly large Zener voltage of the Zener diode D7 in the logic circuit V. In this “unpolarized” mode of operation, however, the voltage between UM and USI and between E and USI can also be greatly increased without disturbing the operation, for. B. to 30 V. Also in this mode of operation there is a huge tolerance, which is • 30 V - 6.8 V = 23.2 V, which is about three and a half times the minimum value of 6.8 V.

For the integration it turned out to be favorable to use a p-substrate with pnp lateral transistors and npn transistors, as shown in FIGS. 2 and 3. The protective diodes D8 / D9, which are intended to protect the push-pull transistors against switch-off voltage peaks from an organ RE formed by a relay, can then also be easily integrated. In particular, a special protective diode D9 can then be omitted because the arrangement of the push-pull transistors on the substrate is such that the protective diode is, as it were, formed by a parasitic pn diode between the substrate and the collector of the T23.

An integrated driver module with bipolar transistors is dealt with above, which has an output push-pull amplifier which is formed by two separately controllable push-pull transistors lying in series. The output amplifier has a tri-state output. Each of the two push-pull transistors is controlled via a constant current source, which is only connected to supply current when the relevant push-pull transistor controlled by it is to be controlled in its conductive state. This driver module is suitable for controlling bipolar telephone relays. Multi-collector transistors, which are known per se, can be used to create constant current sources (see DT-AS 1036 315, DT-OS 2 256 640).

The following shows how this technique can be achieved with particularly little effort.

For this purpose, collectors of a single multi-collector transistor are used as constant current sources, and the current supply switching for the purpose of controlling the push-pull transistors is effected by switching high-impedance switching means which are individually connected to the relevant collectors and by means of which the collector current is otherwise kept away from the relevant push-pull transistor. Since the collectors of a single multi-collector transistor are used as constant current sources, there is a particularly low outlay in terms of circuitry, and the module can be manufactured particularly easily in integrated technology. However, this technique is also advantageous if it is a discrete component interconnected component.

The block is explained in more detail below with reference to FIGS. 4 and 5. Fig. 4 shows a block diagram comprising the output push-pull amplifier and the constant current sources. 5 shows the circuit design of these parts of the module.

4 shows those parts which are important for the explanation. These include the two stages Al 1 and A22 of the output push-pull amplifier. These two stages are connected to the terminals with the voltages Usi and Us2 of the operating voltage source. The three-state output is labeled Q. Either voltage Usi or voltage Us2 can be supplied there, depending on whether stage A1 or stage A22 is controlled to be conductive. The three-state output Q can also be high-impedance, namely if neither of these two stages is controlled. The stages All and A22 are controlled by the constant current sources Sil and S22. These constant current sources are in turn also connected to the terminals with the voltages Usi and Us2. The current supply switching of the constant current sources Sil and S22 can be effected via the control terminals Va and Vb.

5 shows the pnp multi-collector transistor MKT, the collectors kl and k2 of which are used as constant current sources. The one stage of the output push-pull amplifier, to which the npn transistors TI 11 and T112 belong, is connected to the collector kl, and the other stage of the output push-pull amplifier, to which the npn transistors T221 and T222 belong, is connected to the collector k2. The control terminal Va is connected to the collector kl and the control terminal Vb is connected to the collector k2. The schematically represented switching means va and vb, which act like normally closed contacts and which are individually connected to the collectors kl and k2 via the control terminals Va and Vb, are used here to switch the current supply of the constant current sources. In the idle state, the collector current is therefore kept away from the stages of the output push-pull amplifier and thus from the associated push-pull transistors. If the normally closed contact va is actuated, the stage is controlled with the transistors TI 11 and T112. If the normally closed contact vb is actuated instead, the stage is turned on using the transistors T221 and T222. The emitter of the multi-collector transistor MKT is namely connected to the terminal with the voltage Usi of the operating voltage source, which is positive here. The collector k3 and the associated base of the multi-collector transistor MKT is connected via the resistor R to the terminal with the voltage Us2 of the operating voltage source, which here has a negative potential. This circuit technology has the consequence that the multi-collector transistor in

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a state of saturation is controlled so that its collectors kl and k2 can be used as constant current sources. In FIG. 5, the transistor T is also connected in series with the resistor R and is controlled in a conductive manner with the aid of the control voltage Us21 at its base. In this way, the current flowing through the resistor R can be stabilized, which results in particularly constant operating conditions.

The constant current supplied by the collectors of the multi-collector transistor could be used directly to control push-pull transistors of the output push-pull amplifier. In the circuit example shown in FIG. 5, a control transistor is connected upstream of each push-pull transistor. The push-pull transistor T112 is preceded by the control transistor Till and the push-pull transistor T222 by the control transistor T221. The control transistors are used for current amplification and are used for adaptation

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exploited the operating properties of the multi-collector transistor MKT to the operating properties of the push-pull transistors T112 and T222. With the help of the diode G22 and the resistors R111, R112 and R22 the correct functioning of the 5 output push-pull amplifier is ensured.

The switching means va and vb shown as normally closed contacts in FIG. B. realized by transistors, which are occasionally controlled by control signals, but are controlled locked in the idle state.

io The transistors TI 11 and TI 12 are preceded by the diode Gl 1. It is used to protect these transistors when the three-state output Q is connected to the same bus line together with other such outputs from components. It is then prevented that the emitter-base paths of these transistors in the blocking state are subjected to an impermissibly high load by a voltage which is supplied to the output Q.

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Claims (20)

615 296 PATENT CLAIMS 1.Integrated driver module with bipolar transistors and with an output push-pull amplifier, which is formed by two series-connected, separate controllable push-pull transistors, the output amplifier having a three-state output, characterized in that each of the two push-pull transistors (A1 / A2, T23 / T20, Al 1 / A22, TI 12 / T222) of the output push-pull amplifier is controlled via a constant current source (S1 / S2, SI 1 / S22, MKT) that only supplies current when the relevant push-pull transistor controlled by it is controlled in its conductive state . 2. Driver module according to claim 1, characterized in that a logic circuit (V) controlled by an activation signal (EN) is provided, via the output or the outputs of which the push-pull transistors (A1; A2) are controllable and / or their associated constant current sources (SI, S2) are switchable, so that in the absence of the activation signal (EN = L) neither of the two push-pull transistors is controlled in its conductive state. 3. Driver module according to claim 2, characterized in that between the logic circuit (V) and the push-pull transistors (A1, A2) the constant current source (s) (SI, S2) connected by the logic circuit (V) is or are inserted . 4. Driver module according to claim 3, characterized in that between two of its signal inputs (I, EN) and the two push-pull transistors (Al, A2) the logic circuit (V) is inserted, which in turn contains two inputs and two outputs that the first logic input the activation signal (EN) and the second logic input are supplied with an output current polarity signal (I) which determines the polarity of the driver module output current and that one of the two push-pull transistors can be controlled directly or indirectly via the two outputs of the logic circuit (V). 5. Driver module according to claim 2, characterized in that the logic circuit (V) has a further constant source (S3) which stabilizes the currents of the output of the logic circuit (V), so that the logic circuit has a stabilized current corresponding to the output current polarity signal (I) delivers. 6. Driver module according to claim 1, characterized in that a blocking transistor (K1, K2) is attached to each push-pull transistor, which supplies a blocking potential to the push-pull transistor with low resistance when reversing the push-pull transistor from the conductive to the non-conductive state. 7. Driver module according to claim 6, characterized in that the switched (n) constant current source (s) (Sl, S2) is / are formed by a multi-collector transistor (T9 / T10 / Tl 1) and that the basis of each is dependent on the output current polarity signal ( I) controlled, stabilized direct current is supplied. 8. Driver module according to claim 7, characterized in that the first of the collectors (T13, T10) with the control connection of the associated push-pull transistor and the second of the collectors (T14, T9) each with the control connection of one of the blocking switches (Kl, K2 or T24 ) is connected, which in turn - during the control of the push-pull transistor (Al, A2) connected to the emitter-collector path of the blocking switch from its conductive to its non-conductive state - supplies an additional blocking potential which controls this push-pull transistor into the blocking state and supplies this push-pull transistor. 9. Driver module according to claim 7, characterized in that the multi-collector transistor is saturated in the switched-on state. 10. Driver block according to claim 6, characterized in that the blocking switch (Kl, K2) connected to the control input of the push-pull transistor with its emitter-collector path is controlled in the conductive state when the connected push-pull transistor (A1, A2) is controlled in the non-conductive state and vice versa. 11. Driver module according to claim 6, characterized in that the blocking switch (Kl) of a push-pull transistor (AI) is controlled in each case by the constant current source (S2) which directly controls the other push-pull transistor (A2). 12. Driver module according to claim 1, characterized in that the push-pull transistors (Al, A2) are each protected by a protective diode (D8, D9) against switch-off voltage peaks of a relay (RE) connected to the module output (Q). 13. Driver module according to claim 1, characterized in that the push-pull transistors are three-layer transistors, namely NPN transistors. 14. Driver module according to claim 12 and 13, characterized in that the one push-pull transistor (AI) protecting the first protective diode (D9) is formed by a sub-strat-collector-pn junction between the substrate and collector of this push-pull transistor (AI). 13- Driver module according to claim 1, characterized in that the constant current source in each case delivers sufficient current to control the associated push-pull transistor in its saturated state. 16. Driver module according to claim 1, characterized in that each push-pull transistor is assigned its own constant current source. 17. Driver module according to claim 1, characterized in that the two push-pull transistors are assigned the same constant current source. 18. Driver module according to claim 1, characterized in that the constant current sources are the collectors of a single multi-collector transistor (MKT), that the current supply switching for the purpose of controlling the push-pull transistors is effected by high-resistance switching of switching means (Va, Vb), which are individually connected to the relevant collectors (kl , k2) are connected and otherwise the collector current is kept away from the relevant push-pull transistor (TI 12, T222). 19. Module according to claim 18, characterized in that a collector (k3) and the associated base of the multi-collector transistor (MKT) via a resistor (R) to one terminal (Us2) and that its emitter to the other terminal (Usi) the operating voltage source are connected. 20. Module according to claim 19, characterized in that the current flowing through the resistor (R) is stabilized by a transistor (T) which is connected in series and conductively controlled to the resistor (R). 21. Module according to claim 1, characterized in that a control transistor (TI 11, T221) is connected upstream of each push-pull transistor (TI 12, T222).