Miscellaneous active electrical nonlinear devices – circuits – and – Gating – Utilizing three or more electrode solid-state device
Patent
1995-01-17
1995-10-17
Callahan, Timothy P.
Miscellaneous active electrical nonlinear devices, circuits, and
Gating
Utilizing three or more electrode solid-state device
327 66, H03K 1756
Patent
active
054594294
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
Symmetrical bipolar transistors have many applications. In a known application, a bipolar transistor is used as a reverse-polarity protection element in a coupling circuit to a bus system. (See European Patent Publication No. EP-A-0487 759, FIG. 3.) Such reverse-polarity protection is preferably suitable for assemblies in bus systems, in computers and in controllers with a storage capability. The reverse-polarity protection element is located in a signal coupling path and serves as a controllable element which switches the signal coupling path on and off as a function of the polarity of an electrical signal. The known bipolar transistor is designed as a double-emitter transistor whose emitter current can be controlled uniformly in both directions.
A bipolar transistor structure is also generally suitable for checking whether a potential difference is less than a specific value and thus, in addition, whether a voltage is approaching another voltage. Until now, comparators have been used for such applications. The required comparator arrangements are normally rather complex, however. A national German application having an older priority (German Patent Application No. DE-A-43 16 608) discusses a bipolar transistor structure.
If a bipolar transistor structure is intended to be integrated in an integrated circuit, it is desirable to minimize the power losses which occur and to keep the currents for driving such bipolar transistor structures correspondingly low. The object of the present invention is to find a driver circuit for a symmetrical bipolar transistor and for a bipolar transistor structure in an IC circuit, which operates with drive currents which are as low as possible.
SUMMARY OF THE INVENTION
The above mentioned object is achieved by providing an improved driver circuit for controlling a symmetrical bipolar transistor, or for controlling a symmetrical bipolar transistor structure, having two operating electrodes. The driver circuit includes a pair of balanced circuits, a pair of inverse balanced circuits and a switch. The pair of balanced circuits is coupled with the two operating electrodes, are coupled to one another by their bases, and have a reference current supplied to their bases. The pair of inverse balanced circuits are acted upon by collectors of the pair of balanced circuits. The switch is controlled by the pair of inverse balanced circuits and has an open state and a closed state in which a triggering current flows to the base of the symmetrical bipolar transistor. The switch is in the open state when the two operating electrodes of the symmetrical bipolar transistor are at the same potential.
A balanced circuit of a type which is known per se is connected to the two operating electrodes of the symmetrical bipolar transistor or of the symmetrical bipolar transistor structure. The balanced circuit can preferably be connected with the operating electrode by means of its emitter. In this case, the bases of the two balanced circuits are connected to one another, and the collectors of the two balanced circuits act on inverse balanced circuits. The inverse balanced circuits regulate the control current required to control the bipolar transistor. In such an arrangement, using low drive currents for the symmetrical bipolar transistor or the symmetrical bipolar transistor structure is possible. Both arrangements are called bipolar transistors, for short, in the following text.
The balanced circuits can each be extended, as first balanced circuits, by a second amplifying balanced circuit. The second balanced circuits are each connected to a collector of the first balanced circuit. Such an arrangement permits current pulses having a very high edge gradient to be sent via the bipolar transistor.
In a preferred embodiment of the present invention, the second, amplifying balanced circuits are connected, via coupled ENABLE switches, to the first balanced circuits. In each case, the collectors of the first balanced circuits in this case act on one amplifying balanced cir
REFERENCES:
patent: 3207927 (1965-09-01), Wells
patent: 4096399 (1978-06-01), Davis et al.
Sziklai, "Symmetrical Properties of Transistors And Their Applications" pp. 717-724 Proceedings of the I.R.E. Jun. 1953.
Callahan Timothy P.
Siemens Aktiengesellschaft
Zweizig Jeffrey
LandOfFree
Drive for a symmetrical bipolar transistor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Drive for a symmetrical bipolar transistor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Drive for a symmetrical bipolar transistor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-600305