Abstract: An amplifier arrangement includes a class-G amplifier, biased by a first and a second pair of bias voltages, a drive control circuit and a second amplifier (C) biased by the second pair of supply voltages, the drive control circuit (DCD) thereby being adapted to turn on said second amplifier (C) at a higher input signal amplitude than the input signal amplitude at which the current in the class-G amplifier is internally switched over from the first pair to the second pair of bias voltages.

Abstract: The invention relates to a method for selecting a sequence of cells of current sources inside a cell matrix structure of a digital-analog converter and also to the corresponding converter. Symmetries are used with regard to the centre (C) of a rectangular or preferably square matrix structure, with regard to a symmetry point (S) located at a quarter of the length of a diagonal (D1) from the centre and with regard to one of the two mean perpendiculars (M1) of the structure for selecting the mapping areas (1, 2, . . . ) for the consecutive cells.

Abstract: A differential output amplifier arrangement (DOA) including two operational amplifiers (OA1,OA2), each having a feedback resistor (R2,R20), and which are coupled by a first resistor (R1) between similar polarity type input terminals, further includes a pair of output resistors (R3,R30), coupled between respective output terminals (OUT1,OUT2), of each respective operational amplifier, and corresponding respective output terminals (ZOUT1,ZOUT2) of said arrangement, and a pair of resistors (R4,R40), each of which is cross-coupled between a respective output terminal of said arrangement (ZOUT1,ZOUT2) and one of the two similar polarity type, by the first resistor coupled, input terminals (INN2,INN1) of the respective cross-coupled operational amplifier. A method for adapting the output impedance of a differential output amplifier arrangement is described as well.