Atmel Germany Gmbh

Atmel Automotive Gmbh

Temic Semiconductor Gmbh

Karl-Josef Gropper

Herbert Knotz

Stefan Markus Schabel

Holger Vogelmann

Armin Prohaska

Udo Karthaus

Guenther Bergmann

Michael Offenwanger

Knut Brenndoerfer

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 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

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.

Method for feedback control of a controlled variable

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Karl-Josef Gropper