A logarithmic amplifier circuit includes an adaptive gain amplifier circuit and a transistor. The adaptive gain amplifier circuit includes a gain stage and a diode. The gain stage includes an input terminal, and an output terminal. The diode includes a cathode terminal coupled to the output terminal, and an anode terminal coupled to a common terminal. The transistor includes a first terminal coupled to the input terminal, a second terminal coupled to the common terminal, and a third terminal coupled to the output terminal.

An amplifier circuit with an overshoot suppress scheme is provided. The amplifier circuit includes an input amplifier, an output amplifier and a diode device. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier and a method of outputting a waveform of a music signal capable of outputting a waveform of a music signal exceeding a power supply voltage is provided. An amplifier includes a power supply, an input terminal for a music signal, an amplifying circuit which amplifies the music signal using the power supply, and a jumping-up circuit which is connected to an output end of the amplifying circuit and outputs a waveform exceeding a voltage value of the power supply.

An operational amplifier includes a voltage terminal; a common terminal; a first amplification stage for receiving a differential signal pair to generate a single-end amplification signal; a first buffer for generating a first voltage according to the single-end amplification signal; a first diode for reducing the first voltage to generate a second voltage; a second amplification stage for amplifying the second voltage to generate a third voltage; a voltage stabilizing circuit for stabilizing the third voltage; a second diode coupled between the second amplification stage and the common terminal; a second buffer for generating an output voltage according to the third voltage; and a current mirror coupled to the common terminal, the first amplification stage, the first diode and the second amplification stage.

The present invention is directed to electrical circuits. More specifically, an embodiment of the present invention provides a variable impedance module with a first capacitor coupled to a first input terminal and the second capacitor coupled to a second input terminal. A diode bridge is connected between the input capacitors. The anodes of the top diodes are connected to a supply through a resistor, and the cathodes of the lower diodes are connected to a high-impedance current source. A third capacitor is connected between these two nodes.

The present invention is directed to electrical circuits. More specifically, an embodiment of the present invention provides a variable impedance module with a first capacitor coupled to a first input terminal and the second capacitor coupled to a second input terminal. A diode bridge is connected between the input capacitors. The anodes of the top diodes are connected to a supply through a resistor, and the cathodes of the lower diodes are connected to a high-impedance current source. A third capacitor is connected between these two nodes.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier includes a PMOSFET and an NMOSFET. The PMOSFET has a gate electrode serving as a first input end and a drain coupled to an output end. The NMOSFET has a gate electrode serving as a second input end and a drain coupled to the output end. The output amplifier outputs an output voltage at the output end, and is coupled to the input amplifier via at least one of the first and second input ends. The diode device is coupled between the output end and the at least one of the first and second input ends of the output amplifier. When a voltage difference between the output end and the at least one of the first and second input ends of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier and a method of outputting a waveform of a music signal capable of outputting a waveform of a music signal exceeding a power supply voltage is provided. An amplifier includes a power supply, an input terminal for a music signal, an amplifying circuit which amplifies the music signal using the power supply, and a jumping-up circuit which is connected to an output end of the amplifying circuit and outputs a waveform exceeding a voltage value of the power supply.

This technology relates to a single-phase differential conversion circuit for improving the linearity of input/output characteristics, a signal processing method for use with the circuit, and a reception apparatus. The single-phase differential conversion circuit includes a first source-grounded amplifier and a second source-grounded amplifier. Each of the amplifiers includes a transconductance amplifier section including a transistor for converting an AC component of input potential to a current, a diode load section including a transistor in a diode connection configured as a first load, and a large-signal distortion compensation circuit configured as a second load connected in parallel with the first load. The transistors of the first source-grounded amplifier are each a P-type MOS transistor, and the transistors of the second source-grounded amplifier are each an N-type MOS transistor. This technology is applied advantageously to a reception apparatus for receiving TV signals, for example.

An operational amplifier includes a voltage terminal; a common terminal; a first amplification stage for receiving a differential signal pair to generate a single-end amplification signal; a first buffer for generating a first voltage according to the single-end amplification signal; a first diode for reducing the first voltage to generate a second voltage; a second amplification stage for amplifying the second voltage to generate a third voltage; a voltage stabilizing circuit for stabilizing the third voltage; a second diode coupled between the second amplification stage and the common terminal; a second buffer for generating an output voltage according to the third voltage; and a current mirror coupled to the common terminal, the first amplification stage, the first diode and the second amplification stage.