Atmel Germany Gmbh

Atmel Corporation

Atmel Automotive Gmbh

Temic Semiconductor Gmbh

Herbert Knotz

Holger Vogelmann

Karl-Josef Gropper

Stefan Markus Schabel

Guenther Bergmann

Armin Prohaska

Peter Kolb

Michael Offenwanger

Udo Karthaus

Erwin Dotzauer

Knut Brenndoerfer

Wolfgang Wernig

A circuit and method for operating a circuit with a terminal for connecting a photodiode to output an output current dependent on the photocurrent of the photodiode, with a resistance device for generating a voltage drop dependent on a photocurrent of the photodiode, with a control loop connected to the resistance device for generating the output current dependent on the photocurrent, with a switching means connected to the terminal with first switch positions for a first operating mode for operating the photodiode in the reversed bias and with second switch positions for a second operating mode for operating the photodiode in the photovoltaic mode, wherein in the first operating mode in the first switch positions of the switching means, the resistance device and the control loop are bridged and/or are not connected, and in the second operating mode in the second switch positions of the switching means, the terminal is connected to the resistance device.

Circuit and method for operating a circuit

A laser driver circuit comprising an amplifier device with a plurality of switchable subamplifiers, which can be or are connected to an output for connection of a laser, ith an analog switching device for switching of analog input signals, a plurality of analog inputs for the analog input signals, a plurality of control inputs for receiving digital control signals, wherein each switchable subamplifier has a switching device for switching the amplification by one of the digital control signals, a digital switching device connected to an input of each switching device for the selectable connection of the input of the switching device of each switchable subamplifier to a control input. Whereby each switchable subamplifier has an analog input, which is connected to the analog switching device for the selectable switching of an analog input signal to the analog input.

Laser driver circuit, method for controlling a laser driver circuit, and use

A laser drive circuit and use of digital-to-analog converters is provided, each with a current input and a current output to set current values of partial currents switchable by means of digital channel signals to provide a laser current pulse at least on the basis of a sum of partial currents, wherein at least one current output of one of the digital-to-analog converters is connected to at least one current input of an additional digital-to-analog converter via an analog switch.

Laser drive circuit and use

A method is provided for determining a laser threshold of a laser diode, which is operated by a drive circuit as a function of a first signal in a first feedback and a second signal in a second feedback, the first feedback being supplied via an optical coupling of an optical output signal of the laser diode. The method is characterized in that the second feedback is supplied by an electrical signal picked up between the drive circuit and the laser diode, the electrical signal is compared with an adjustable activation threshold, only a portion of the electrical signal that exceeds the adjustable activation threshold is transmitted to the drive circuit in such a way that the second feedback is active only when such a portion occurs, the adjustable activation threshold is changed in such a way that the activity state of the second feedback changes, and the laser threshold of the laser diode is determined as a function of the value of the adjustable activation threshold during a change in the activity state of the second feedback. Furthermore, a drive circuit is presented which carries out the method.

Method and device for determining an activation threshold

A driver circuit is provided, which includes a differential amplifier whose output signal controls the driving input signal, a reference signal generator that supplies a reference input of the differential amplifier, an external feedback that applies a signal, which is dependent on the output signal, to a feedback input of the differential amplifier, an adapter circuit, and an internal feedback activated in a compensation mode as an alternative to the external feedback, which internal feedback provides a signal to both the feedback input and the adapter circuit even for input signals that do not exceed the first threshold. The adaptor circuit generates and stores a compensation signal that compensates an offset signal acting alone at the reference input when the reference signal generator is switched off, and feeds the stored compensation signal, together with a reference signal, to the reference input or feedback input when the external feedback is activated.

Driver circuit with automatic offset compensation of an amplifier and method for offset compensation of an amplifier of a driver circuit

An amplifier array includes a servo amplifier, which has a reference signal input, a return signal input, and an output signal connection, which supplies an output signal path, a reference signal generator, which supplies reference signals with different level heights to the reference signal input, and with a return, which supplies a signal, attenuated by a value of the feedback attenuation, from the output path as a return signal to the return signal input, whereby the servo amplifier supplies an amplified difference between the reference signal and return signal in the output signal path. The amplifier array has a connectable bypass gain path, which in the connected state is supplied phase-coupled to the reference signal generator and which supplies a bypass output signal in the output path.

Signal amplification method and amplifier array

A driver circuit and a method drive an electronic component such as a laser diode with a variable electric current that is controlledly switched between at least two discrete current levels. The driver circuit includes circuit elements that damp ringing or initial transient oscillations that arise when switching the current between the current levels. The driver circuit includes a current mirror having a mirror amplification factor dependent on the frequency of the variable electric current. In order to counteract parasitic capacitances and/or inductances leading to the ringing, an inductance and/or a resistance are connected between the two series circuits making up the current mirror, a capacitance is connected parallel to a reference resistor of one of the series circuits, and/or a capacitance is connected across the voltage supply.

Driver circuit and method for driving an electronic component

A signal when transmitting digital transmission signals between a transmitter unit and at least one receiver unit, one signal lead is generally required as a transmission medium for each digital transmission signal. To permit simultaneous transmission of several digital transmission signals through a common signal lead, the digital transmission signals (S,. . . S,) are totaled with several logical signal levels in the transmitter unit (,) to form a multilevel signal (m). This multilevel signal (m) is transmitted from the transmitter unit (,) to the receiver unit (,) through a signal lead (,). For the purpose of forming digital received signals (S,. . . S,) corresponding to the digital transmission signals (S,. . . S,), the received multilevel signal (m) is compared in the receiver unit (,) with signal thresholds (V,. . . V,) located between the logical signal levels of the multilevel signal (m).

Method for transmitting digital signals

Method for automatically controlling a controlled variable. In a feedback control process, a control loop is used to compare the controlled variable with a command variable that determines the setpoint of the controlled variable and minimizes a deviation between setpoint and actual value of the controlled variable with the help of a manipulated variable that acts on the controlled variable. A disadvantage of this process is the transient behavior of the control loop due to temperature influences and degradation phenomena. The method according to the invention is intended to prevent a change in the transient behavior of the control loop. In accordance with the invention, the loop gain (A) of the control loop (1) is regulated to a value at which the actual value of the controlled variable (x) overshoots the setpoint value (s) by a predetermined tolerance value (m) as the result of a pulse-shaped change in the command variable (w). Consequently, the controlled variable (x) settles to the setpoint value (s) in a minimum of time and ensures stable feedback control operation. The circuiting of the invention is suited for feedback control of the emission power of light sources, in particular of laser diodes.

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Erbach, Germany

Herbert Knotz