Temic Telefunken Microelectronic Gmbh

Atmel Germany Gmbh

Hermann Hammel

Jurgen Schnabel

Friedemann Schmidt

Henrik Gutsch

Horst Hafner

Hans-Peter Waible

Wolfgang Roeper

Horst Haefner

Juergen Schnabel

Reinhard Reimann

Burkhard Gehring

Gerald Krimmer

Thorsten Fahlbusch

Juergen Eckert

Hans-Werner Groh

Michael Hecker

Wolfgang Schneider

Michael Vogt

A d.c. signal controlled oscillator includes a frequency-determining network having a control input and a modulation input. A phase regulating loop includes the oscillator and components that provide a control signal to the control input. A circuit apparatus for driving the oscillator includes a modulation generator that provides a modulation signal to the modulation input, and a circuit arrangement that autonomously generates a signal depending on and representing a slope of the modulation and provides this slope signal to the modulation generator, which generates the modulation signal dependent on the slope signal. A method of operating the oscillator involves switching a frequency divider successively to two different frequencies, respectively sampling and holding the two different arising control voltages, forming a difference between the two control voltages, and activating the modulation generator so that a modulation swing of the modulation signal is determined by this difference between the control voltages.

Method and apparatus for driving a direct current or voltage controlled oscillator with modulation slope feedback

In order to protect against any damage caused by electrostatic discharges, an integrated circuit layout is provided with at least one circuit connection which is connected via one of two diodes, respectively, to a first supply line and a second supply line. The diodes are reverse biased, i.e., one of them becomes conductive if a potential exists at the circuit connection that is either higher or lower than the supply potentials applying to the supply lines. The circuit layout is provided with an overvoltage suppression device connecting the two supply lines. The overvoltage suppression device is switched into a low impedance state by a steep rate increase or rise in a supply voltage applied between the supply lines such that a discharge current counteracting the increase in the supply voltage will flow via the overvoltage suppression device from the one supply line to the other supply line, and the discharge energy is converted into heat in the overvoltage suppression device.

Electrostatic discharge circuit layout

A switch is described with a bipolar transistor as first switching element having a high breakdown voltage when operated in the reverse direction. This can be accomplished by a second switching element provided in the switch, a switching transistor, e.g. an MOS transistor, through which the base and the collector of the bipolar transistor are joined together, is activated in the reverse mode of the switch, i.e. when the bipolar transistor is in inverse mode, in such a way that the second switching element becomes conductive. The collector-emitter breakdown voltage of the bipolar transistor, i.e. its maximum permissible collector-emitter voltage, is thus brought closer to its higher base-emitter breakdown voltage.

Switch with a first switching element in the form of a bipolar transistor

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Rot am See, Germany

Hermann Hammel