Siemens Aktiengesellschaft

Hans Kriedt

Josef Fenk

Andreas Dietze

Heinz Zietemann

Jean-Marc Zulauf

Wladimir Mueller

Eckart Shatter

A monolithically integratable transistor circuit for limiting transient positive high voltages on an electric conductor includes a pnp transistor being conductive only upon exceeding a predetermined potential threshold value being positive as compared with a reference potential. The pnp transistor has an emitter terminal connected to an electric conductor, a collector terminal connected to the reference potential, and a base terminal. A parallel circuit is connected between the base terminal and the electric conductor. The parallel circuit has a high-impedance resistor and a first capacitor. A second capacitor is connected between the base terminal and the reference potential.

Monolithically integratable transistor circuit for limiting transient

Integrated semiconductor circuit, including a control loop including a first current source acting as an actual value transmitter for the control loop, and a final control element acting on the first current source as a control, the first current source being in the form of a current mirror having a plurality of transistors each forming an output part driving a respective load element, and a second constant current source being independent of the first current source and acting as a desired value transmitter for the control loop.

Integrated semiconductor circuit

A circuit configuration for low-distortion switching of signals to a given operating potential includes a countercoupled operational amplifier having an output, a push-pull end stage connected to the output, a differential amplifier stage connected to the push-pull end stage, a switchable resting current source for the differential amplifier stage, and a segment to be switched. The segment has end points being defined by the output of the operational amplifier and a reference potential being the reference potential of the operational amplifier.

Circuit configuration for low-distortion signal switching

Integrable frequency divider circuit, including a preamplifier in the form of a differential amplifier having a signal input for receiving signals to be processed, a reference input and two outputs, a frequency divider having divider stages including a first divider stage, each being in the form of identical series-connected flip-flop cells, the first divider stage having two inputs each being connected to a respective one of the two outputs of the differential amplifier for receiving the signals to be processed, an operational amplifier having an output directly connected to the reference input of the differential amplifier and having two inputs, two resistors each being connected between a respective one of the inputs of the operational amplifier and a respective one of the outputs of the differential amplifier, a capacitor connected between the inputs of the operational amplifier, and another capacitor connected between the output of the operational amplifier and reference potential.

Integrable frequency divider circuit having a feedback controlled

Integrable signal-processing semiconductor circuit, including four transistors being combined into two pairs, the transistors of each pair being connected together through their current inputs forming first and second differential amplifiers, the current outputs of one transistor of each transistor pair being connected to each other and to a first signal output and the current outputs of the other transistor pair being connected to each other and to a second signal output, third and fourth differential amplifiers addressed by first and second signals, first and second current mirror amplifiers each being connected to one output of the third differential amplifier, third and fourth current mirror amplifiers each being connected to one output of the fourth differential amplifier, reference potential connected to the current mirror amplifiers, a supply potential connected to the current outputs of the transistors, two load elements connected to the supply potential, the current inputs of the transistors of the first differential being connected to the first current mirror amplifier and the current inputs of the transistors of the second differential amplifier being connected to the second current mirror amplifier, the controls of one transistor of each pair being connected together to the third current mirror amplifier and through one load element to the supply potential, and the controls electrode of the other transistor of each pair being connected together to the fourth current mirror amplifier and through the other load element to the supply potential.

Integrable signal-processing semiconductor circuit

Monolithically integrable lowpass filter circuit having at least one capacitor and one ohmic resistor includes a signal input, a circuit node connected to the signal input, a first series resistor connected between the signal input and circuit node, an operational amplifier, a signal output connected to the output of the operational amplifier and to the circuit node, a second resistor connected between the circuit node and the signal output, a third resistor connected between the circuit node and the non-inverting input of the operational amplifier, and a capacitor connected between the non-inverting input and ground, the signal output being further connected to the inverting input of the operational amplifier.

Monolithically integrable lowpass filter circuit

Amplifier for aperiodic signals with a base-coupled and an emitter-coupled differential amplification stage in which the emitters and the bases of the two differential amplification stages respectively form an input of which one can be charged with a signal and the respectively other one is capacitively grounded; a third input lies at the directly coupled emitters of the emitter-coupled differential amplification stage; the collectors of both differential amplification stages are cross-coupled; the bases of the base-coupled differential amplification stage is connected to supply potential with a series resistor; static dc currents are fed into the inputs so that a current of the same magnitude flows over the inputs at the bases and emitters of the differential amplification stages and a current of double magnitude flows over the third input.

Amplifier circuit arrangement for aperiodic signals

Circuit arrangement for the compensation of leakage currents in control elements used for wide band amplifiers, said control elements including two transistors whose bases and collectors are respectively directly connected to one another, whose emitters form the resistor connections and in whose bases a control current is fed. A further identical control element is provided into which such a current is fed that a control current with the value required for the control process flows over its control branch; the control branch of this control element being connected to the control branch of the control element lying in the wide band amplifier for the purpose of feeding in the same control current.

Dynamic resistor current leakage compensation arrangement

A common emitter differential amplifier is arranged to receive an amplitude modulated high frequency signal and demodulate it. The common emitter differential amplifier has the emitters of two transistors connected together and these emitters are then connected through a constant current source to a reference potential. At least one of the collectors of the two transistors is connected through a collector resistor to a potential source. The collector of the other transistor is connected to the same potential source either directly or through a resistor associated with it. Negative feedback is provided through a serially connected rectifier and current amplifier. The output of the current amplifier is also connected through a low pass filter to an output terminal. The high frequency signal is fed to the base of one of the above transistors, while the base of the other transistor is connected to a reference voltage. When it is desired to have the differential amplifier provide push-pull rectification, two rectifiers are connected to the current amplifier in the feedback path from the collectors respectively, of the differential amplifier transistors. An improved circuit is shown for push-pull rectification in the negative feedback arm with symmetrical operation of the differential amplifier.

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Munich, Germany

Hans Kriedt