The invention relates to a signal amplifier circuit for amplifying a signal, in particular an audio amplifier circuit, includes at least one first amplifier transistor (Q1) and at least one second amplifier transistor (Q2), wherein the first amplifier transistor (Q1) and the second amplifier transistor (Q2) are connected to one another in a push-pull circuit and are fed by an amplifier voltage source (V+, V−); and one or more bias diodes (D1, D2) thermally coupled in each case to an associated amplifier transistor (Q1, Q2), wherein the bias diodes (D1, D2) are arranged in a parallel connection with respect to the amplifying transistors (Q1, Q2) to reduce or avoid a crossover distortion, wherein the bias diodes (D1, D2) are fed at least partly by a voltage source (UA) which is independent of the amplifier voltage source (V+, V−). The invention furthermore relates to a system and a voltage converter for providing an output-side DC voltage, including a first transformer (T1) and a second transformer (T2) connected to the first transformer (T1).

An electrical system includes a power supply and an electrical circuit coupled to the power supply and including an operational amplifier. The operational amplifier includes an input stage and a pre-driver stage coupled to the input stage, wherein the pre-driver stage includes a first input terminal, a second input terminal, and a voltage supply terminal. The operational amplifier also includes an output stage with bipolar transistors coupled to the pre-driver stage. The pre-driver stage is configured to: detect a voltage differential across the first and second input terminals of the pre-driver stage; and provide an adjustable bias current based on the voltage differential.

A current-bootstrap comparator includes a receiving unit, a first current generation unit and a second current generation unit. The receiving unit receives a load voltage signal, a low threshold voltage and a high threshold voltage. The first current generation unit generates a first current. The second current generation unit generates a second current having a magnitude substantially same as a magnitude of the first current and a direction reverse to the first current. The first current and the second current are supplied to a next-stage circuit as a source current and a corresponding sink current, respectively, when the level of the load voltage signal is higher than the high threshold voltage or lower than the low threshold voltage. The magnitudes of the first current and the second current substantially equal zero when the level of the load voltage signal is between the high threshold voltage and the low threshold voltage.

An audio reproduction apparatus is shown and includes an amplifier with a power amplification stage having transistors in a push-pull arrangement. A bias generator biases the transistors with a standing current. A processor receives a data stream comprising digital samples of an analog audio signal and analyzes the peak level of each group. It then determines the appropriate standing currents to maintain Class A operation of the power amplification stage given the peak levels of each of the groups. A digital to analog converter produces an analog input signal for the input stage of the amplifier from the data stream. A feedforward path between the processor and the bias generator allows the standing current to be adjusted prior to the arrival of the analog input signal in the power amplification stage.

An inductor-less low noise amplifier (LNA) with high linearity is disclosed. The low noise amplifier includes: an input signal stage receiving an input signal; a first amplifier configured to receive the input signal, generate a first amplification signal by amplifying the received input signal, and output the generated first amplification signal, as a first output signal, to a first output terminal; a second amplifier configured to receive the input signal, generate a second amplification signal by amplifying the received input signal, and output the generated second amplification signal, as a second output signal, to a second output terminal; an output signal stage outputting a superimposition signal obtained by superimposing the first output signal and the second output signal; a first resistor feeding back the superimposition signal to the input signal stage; and a switch connecting/disconnecting between the input signal stage and the output signal stage.

Systems and methods for amplifying signals. In some embodiments, the signals may be amplified using a diode steering network with an amplifier operated in class AB mode. In some embodiments, distortion in the amplified signal may be corrected using a feed forward cancellation circuit operated in class A mode.

An inverter circuit arrangement that connects an IO-link master with a slave includes an AB class transistor circuit of which the currents are replicated by a current mirror to a terminal of the slave. A bias circuit provides bias voltages to the AB class transistors. A comparator forms a feedback between the master and slave terminals. The circuit provides for a bidirectional inversion to make a slave device IO-link compatible.

The invention relates to a signal amplifier circuit for amplifying a signal, in particular an audio amplifier circuit, includes at least one first amplifier transistor (Q1) and at least one second amplifier transistor (Q2), wherein the first amplifier transistor (Q1) and the second amplifier transistor (Q2) are connected to one another in a push-pull circuit and are fed by an amplifier voltage source (V+, V−); and one or more bias diodes (D1, D2) thermally coupled in each case to an associated amplifier transistor (Q1, Q2), wherein the bias diodes (D1, D2) are arranged in a parallel connection with respect to the amplifying transistors (Q1, Q2) to reduce or avoid a crossover distortion, wherein the bias diodes (D1, D2) are fed at least partly by a voltage source (UA) which is independent of the amplifier voltage source (V+, V−). The invention furthermore relates to a system and a voltage converter for providing an output-side DC voltage, including a first transformer (T1) and a second transformer (T2) connected to the first transformer (T1).

The invention relates to a signal amplifier circuit for amplifying a signal, in particular an audio amplifier circuit, includes at least one first amplifier transistor (Q1) and at least one second amplifier transistor (Q2), wherein the first amplifier transistor (Q1) and the second amplifier transistor (Q2) are connected to one another in a push-pull circuit and are fed by an amplifier voltage source (V+, V−); and one or more bias diodes (D1, D2) thermally coupled in each case to an associated amplifier transistor (Q1, Q2), wherein the bias diodes (D1, D2) are arranged in a parallel connection with respect to the amplifying transistors (Q1, Q2) to reduce or avoid a crossover distortion, wherein the bias diodes (D1, D2) are fed at least partly by a voltage source (UA) which is independent of the amplifier voltage source (V+, V−). The invention furthermore relates to a system and a voltage converter for providing an output-side DC voltage, including a first transformer (T1) and a second transformer (T2) connected to the first transformer (T1).

An exemplary embodiment of the invention relates to an electrical amplifier comprising a differential preamplifier having a first output port and a second output port; and a downstream amplifier stage having a first output unit and a second output unit; wherein the first output unit is connected to the first output port of the differential preamplifier and the second output unit is connected to the second output port of the differential preamplifier; and wherein a negative impedance converter is electrically located in at least one of said differential preamplifier and said downstream amplifier stage.