The present disclosure relates an interface unit having an input for receiving an input voltage from an electrochemical measuring probe; a first transistor; a first operational amplifier; a second transistor; and a second operational amplifier. The first operational amplifier is arranged to provide a variable tension to a first source terminal of the first transistor, in accordance with a comparison between a reference voltage and a second resistor voltage, in order to control an operating point of the first transistor.

A push-pull dynamic amplifier is operable in reset and amplification phases. The amplifier includes first NMOS and PMOS input transistors that are electrically coupled to a first input terminal and a first output terminal. Second NMOS and PMOS input transistors are electrically coupled to a second input terminal and a second output terminal. First and second reset switches are electrically coupled to the first and second output terminals, respectively. A power supply switch is electrically coupled to the first and the second PMOS transistors, and a ground switch is electrically coupled to the first and the second NMOS transistors. During the reset phase, the reset switches are closed and the power supply switch and the ground switch are opened. During the amplification phase, the reset switches are opened and the power supply switch and the ground switch are closed.

A push-pull dynamic amplifier is operable in reset and amplification phases. The amplifier includes first NMOS and PMOS input transistors that are electrically coupled to a first input terminal and a first output terminal. Second NMOS and PMOS input transistors are electrically coupled to a second input terminal and a second output terminal. First and second reset switches are electrically coupled to the first and second output terminals, respectively. A power supply switch is electrically coupled to the first and the second PMOS transistors, and a ground switch is electrically coupled to the first and the second NMOS transistors. During the reset phase, the reset switches are closed and the power supply switch and the ground switch are opened. During the amplification phase, the reset switches are opened and the power supply switch and the ground switch are closed.

The present disclosure relates an interface unit having an input for receiving an input voltage from an electrochemical measuring probe; a first transistor; a first operational amplifier; a second transistor; and a second operational amplifier. The first operational amplifier is arranged to provide a variable tension to a first source terminal of the first transistor, in accordance with a comparison between a reference voltage and a second resistor voltage, in order to control an operating point of the first transistor.

A push-pull dynamic amplifier is operable in reset and amplification phases. The amplifier includes first NMOS and PMOS input transistors that are electrically coupled to a first input terminal and a first output terminal. Second NMOS and PMOS input transistors are electrically coupled to a second input terminal and a second output terminal. First and second reset switches are electrically coupled to the first and second output terminals, respectively. A power supply switch is electrically coupled to the first and the second PMOS transistors, and a ground switch is electrically coupled to the first and the second NMOS transistors. During the reset phase, the reset switches are closed and the power supply switch and the ground switch are opened. During the amplification phase, the reset switches are opened and the power supply switch and the ground switch are closed.

A push-pull dynamic amplifier is operable in reset and amplification phases. The amplifier includes first NMOS and PMOS input transistors that are electrically coupled to a first input terminal and a first output terminal. Second NMOS and PMOS input transistors are electrically coupled to a second input terminal and a second output terminal. First and second reset switches are electrically coupled to the first and second output terminals, respectively. A power supply switch is electrically coupled to the first and the second PMOS transistors, and a ground switch is electrically coupled to the first and the second NMOS transistors. During the reset phase, the reset switches are closed and the power supply switch and the ground switch are opened. During the amplification phase, the reset switches are opened and the power supply switch and the ground switch are closed.

The electronic circuit having an input stage for pre-amplifying an electrical input signal of the electronic circuit provided by a transducer. The electronic circuit has an output stage for providing a microphone output signal by processing an output signal of the input stage. The electronic circuit has an adjustable output load arranged and configured for setting a current draw of the output stage. Additionally, the electronic circuit has a measurement circuit configured to capture the output signal of the input stage and an automatic control circuit configured to adjust the adjustable output load dependent on the captured output signal of the input stage.

Design of ultra broadband transimpedance amplifiers (TIA) for optical fiber communications is disclosed. In one embodiment, a TIA comprises a g.sub.m-boosted dual-feedback common-base stage, a level shifter and an RC-degenerated common-emitter stage, and a first emitter-follower stage, wherein the first emitter follower stage is inductively degenerated. An output of the TIA is buffered using a second emitter-follower stage.

A first circuit unit of an audio amplifier includes a first emitter follower connected to an pre stage input terminal, a second emitter follower connected to an pre stage input terminal, a main transistor connected to an output path of the first emitter follower and an output path of the second emitter follower, a first resistor and a second resistor, which are series-connected between the output path of the first emitter follower and a DC voltage source, and a zener diode connected to a series-connection point between the first resistor and the second resistor. A second circuit unit has a circuit configuration that is complementary to the first circuit unit. A path leading to a collector of each transistor configuring the first and second emitter followers in one of the circuit units is connected to the series-connection point in the other circuit unit.

A first circuit unit of an audio amplifier includes a first emitter follower connected to an pre stage input terminal, a second emitter follower connected to an pre stage input terminal, a main transistor connected to an output path of the first emitter follower and an output path of the second emitter follower, a first resistor and a second resistor, which are series-connected between the output path of the first emitter follower and a DC voltage source, and a zener diode connected to a series-connection point between the first resistor and the second resistor. A second circuit unit has a circuit configuration that is complementary to the first circuit unit. A path leading to a collector of each transistor configuring the first and second emitter followers in one of the circuit units is connected to the series-connection point in the other circuit unit.