Siemens Aktiengesellschaft

Infineon Technologies Ag

Udo Matter

Stefan Heinen

Christian Grewing

Stefan Van Waasen

Stephan Weber

Klaus Getta

Abdul-Karim Hadjizada

Faramarz Rassouli

A voltage-controlled oscillator for frequency modulation includes an oscillator core with a tunable resonant circuit component which is driven with a control voltage. Furthermore, a modulator component is provided which is driven with a modulation signal for frequency modulation. The modulator component is additionally coupled to the terminal for supplying the control voltage. As a result, a constant modulation deviation can be achieved over the entire tuning range even in the case of oscillators having a large tuning range. The oscillator circuit is particularly suitable for use in transmitting circuits for digital communication.

Voltage-controlled oscillator for frequency modulation

A signal to be produced, which represents a digital data stream, is generated using the currents or voltages from current or voltage sources selected from multiple current or voltage sources. The current or voltage sources whose currents or voltages are used to generate the signal which is to be produced are selected based on the contents of the elements of a shift register whose input connection has the signal which is to be filtered applied to it.

Apparatus and method for filtering a signal which represents a digital data stream

The ON and OFF states of a second device are controlled by a first device through a three-conductor bus. The bus carries data, clock, and enable signals and the second device is in the OFF state when all the signals of the three-conductor bus have an L level. The second device is in the ON state when at least one of the signals has an H level (higher potential than the L level). The enable signal is set to the H level during the data transmission. Otherwise, it carries an L level, while the data or clock signal has an H level. The system obviates an additional housing pin. The operating state information is transmitted relatively rapidly.

Method and circuit configuration for controlling operating states of a

A circuit for generating a reference potential includes a first transistor having an emitter connected to a ground potential, a base, and a collector connected to the base; a second transistor having a base connected to the base of the first transistor; a first resistor connected between the collector of the first transistor and an output terminal outputting the reference potential; a second resistor connected between the collector of the second transistor and the output terminal; a third resistor connected between the emitter of the second transistor and ground potential; a third transistor having a base connected to the collector of the second transistor, and an emitter connected to the ground potential; a fourth transistor having a collector connected to a supply potential, an emitter connected to the output terminal, and a base connected to the collector of the third transistor; a first current source connected between the base and the collector of the fourth transistor; and a second current source connected in parallel with the first current source, the second current source generating a compensation current compensating for current fluctuations of the first current source.

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Düsseldorf, Germany

Udo Matter