Patent application number | Description | Published |
20080315952 | POWER AMPLIFIER SYSTEM PROVIDED WITH IMPROVED PROTECTION FUNCTION - A power amplifier system including a power terminal, a ground terminal, an output terminal, a ripple terminal, a control terminal to which a control signal is supplied from outside, a power amplifier circuit connected between the power terminal and the ground terminal, a negative potential detection circuit connected to the output terminal, and a bias circuit which supplies a bias voltage to the power amplifier circuit, and a bias start-up circuit controlling the startup operation of the bias circuit. | 12-25-2008 |
20090002072 | POWER AMPLIFICATION DEVICE - A power amplification device includes a BTL amplification circuit including a first amplification circuit and a second amplification circuit, the first amplification circuit including a first output transistor, a first power detection circuit, a second output transistor, and a second power detection circuit, the second amplification circuit including a third output transistor, a third power detection circuit, a fourth output transistor, and a fourth power detection circuit, a first comparator which compares output values of the first and fourth power detection circuits, and a second comparator which compares output values of the second and third power detection circuits. | 01-01-2009 |
20090010454 | INTEGRATED CIRCUIT DEVICE AND AUDIO SYSTEM - An n-channel integrated circuit device (n is an integer of 1 or greater) for muting an audio signal includes a control circuit configured to generate a control signal and a delayed control signal, a charging and discharging circuit configured to charge and discharge a time constant control terminal according to the control signal and the delayed control signal, an N-th voltage-to-current converting circuit (N is an integer from 1 to n) configured to generate a (2N−1)-th current corresponding to a voltage on the time constant control terminal and a (2N)-th current corresponding to an intermediate voltage, a (2N−1)-th mirror circuit configured to copy the (2N−1)-th current to generate (4N−3)-th and (4N−2)-th intermediate currents, a (2N)-th mirror circuit configured to copy the (2N)-th current to generate (4N−1)-th and (4N)-th intermediate currents, a (2N−1)-th selecting and combining circuit configured to combine a (2N−1)-th mute control current using the (4N−3)-th intermediate current and the (4N−1)-th intermediate current, and a (2N)-th selecting and combining circuit configured to combine a (2N)-th mute control current using the (4N−2)-th intermediate current and the (4N)-th intermediate current. | 01-08-2009 |
20110163809 | PUSH-PULL OUTPUT CIRCUIT - According to one embodiment, a first transistor is connected between a first power supply rail and an output unit. A second transistor is connected between the output unit and a second power supply rail. A gm amplifier includes an input unit and first and second output terminals and amplifies a difference between a signal input to the input unit and a reference voltage. First and second current mirror circuits are connected to be vertically stacked between the first rail and the first terminal as well as a gate of the second transistor. Third and fourth current mirror circuits are connected to be vertically stacked between the second rail and the second terminal as well as a gate of the first transistor. The gate of the first transistor is connected to the first and second circuits. The gate of the second transistor is connected to the third and fourth circuits. | 07-07-2011 |
20130038395 | POWER AMPLIFYING CIRCUIT - A power amplifying circuit includes first and second operational amplifiers. The power amplifying circuit includes first to fourth feedback resistor. The power amplifying circuit includes a fully differential operational amplifier that is connected to the output terminal of the first operational amplifier at a non-inverting input terminal thereof, to the output terminal of the second operational amplifier at an inverting input terminal thereof, to a first signal output terminal at a non-inverting output terminal thereof, and to a second signal output terminal at an inverting output terminal thereof and maintains a constant differential gain. The power amplifying circuit includes a switching circuit. The power amplifying circuit includes first and second input resistors. The power amplifying circuit includes a midpoint potential controlling circuit that monitors a power supply voltage and controls the switching circuit. | 02-14-2013 |
20130195289 | POWER AMPLIFYING APPARATUS AND AUDIO SYSTEM - The power amplifying apparatus includes a first comparator that compares the first detection signal and the fourth detection signal and outputs a first comparison signal depending on whether or not a difference between the first current and the fourth current is equal to or greater than a first predetermined value. The power amplifying apparatus includes a second comparator that compares the second detection signal and the third detection signal and outputs a second comparison signal depending on whether or not a difference between the second current and the third current is equal to or greater than a second predetermined value. | 08-01-2013 |
20140167850 | CURRENT FEEDBACK OUTPUT CIRCUIT - The current feedback output circuit includes first and second transistors. The current feedback output circuit includes a current amplifier that has a non-inverting input terminal, an inverting input terminal, a first output terminal and a second output terminal, an input impedance of the non-inverting input terminal being higher than an input impedance of the inverting input terminal, and flows a current obtained by amplifying the difference between a current of an input signal to the non-inverting input terminal and a current input to the inverting input terminal between the first output terminal and the second output terminal. The current feedback output circuit includes first to sixth current mirror circuits. The current feedback output circuit includes a current feedback circuit that supplies a current responsive to a voltage at the signal output terminal to the inverting input terminal. | 06-19-2014 |