Abstract: A power amplifier is provided with a peak-holding means for holding, for a given period of time, a peak value of an input signal or an output signal of a power amplifying element there of and is provided also with a switching means for switching, to a selected value in accordance with an output from the peak-holding means, a dc power supply voltage which is supplied to said power amplifying elements. Such amplifier is able to enhance the power efficiency of the power amplifier as well as to reduce switching noises and to reduce the development of distortions.

Abstract: First and second direct-coupled cascade connections of like numbers of transistors of the same conductivity type are connected in push-pull. The output stages have common-emitter and common-collector-amplifier transistors, respectively, while earlier stages have common-collector and common-emitter-amplifier transistors, respectively, the common-emitter-amplifier transistor working into a constant current generator collector load.

Abstract: A circuit responsive to applied audio signals for amplifying the same and providing the amplified signals across differential output terminals. The circuit comprising an audio amplifying section which is responsive to the audio input signals for amplifying the same and a feedback circuit connected across the output terminals for providing a feedback signal to the amplifier section to reduce any direct current offset voltage errors appearing across the output terminals to a minimum value. Additionally, the amplifier section includes circuitry for setting the quiescent voltage bias levels of the output terminals to a predetermined level and for providing common-mode rejection of voltage supply line ripple.

Abstract: An amplifier for use as on the output buffer for semiconductor memories including an amorphous element added to a push-pull configuration to allow conversion between push-pull and open collector nonvolatile configurations by electrically altering the impedence of the amorphous element.

Abstract: A bi-state linear amplifier is provided which, in response to a first state of a control signal, functions as a linear amplifier, and in response to a second state of a control signal, is cut off to define a high output impedance. The amplifier includes a control circuit responsive to relatively low-current control signals for selectively opening and closing the internal amplification circuit of the amplifier.

Abstract: An amplifier for use as on the output buffer for semiconductor memories including a fusible element added to a push-pull configuration to allow permanent conversion to an open collector configuration by blowing the fusible element or including a semiconductor element added to a push-pull configuration to cause it to have an open collector configuration and being permanently converted to a push-pull configuration by shorting the semiconductor element.

Abstract: A broad-band radio-frequency amplifier is characterized by a gain which may be adjusted over a relatively large range, and which remains stable over the range of gain adjustments. The amplifier includes first and second transistor pairs each arranged in a cascode connection; a feedback capacitor connected across the output and input of each cascode pair; and inductance serially included at selected circuit points. Also disclosed is a hybrid circuit for efficiently implementing the amplifier.

Abstract: A series circuit comprising a detection transistor and detection resistor is connected in parallel with a decoupling capacitor connected to a signal input terminal of a class B push-pull amplifier. During a power supply OFF period the decoupling capacitor is discharged through the detection transistor and resistor and a drive transistor is turned ON by a voltage generated across the detection resistor, thereby preventing generation of a residual sound and pop sound.

Abstract: A power amplifier device comprises a power amplifier including an output transistor and voltage is applied to the output transistor from a source through a switching type stabilized source device. The source device produces a reference voltage equal to the sum of the output voltage of the amplifier and a constant voltage required to be impressed across the collector and emitter electrodes of the output transistor.

Abstract: A low level, low power, direct coupled integrated class B amplifier having a dual channel three stage preamplifier and a pair of output transistors, one for each channel. In each channel, a DC negative feedback loop connects the collector of the last stage preamplifier transistor to the base of the first stage preamplifier transistor to regulate the DC levels, and a resistive AC negative feedback loop connects the output transistor collector to the first preamplifier transistor collector to reduce the gain dependence of the channel on the current through the output transistor, thus enabling very low idle currents for the output transistors and also providing low distortion output. The resistor in each AC feedback loop is a floating tub resistor to enable it to be taken more than 0.6 volts above the battery voltage. Common mode rejection is provided for at least two of the three preamplifier transistors of each channel.

Abstract: An improved fall time is achieved in bipolar transistor logic circuits which have three-state outputs. The circuits comprise a logic input terminal which is coupled to a push-pull output stage to drive a three-state output terminal. A three-state input receives three-state control signals for holding the output transistors in their non-conducting, high impedance state. Improved speed is achieved by adding a feedback circuit to remove stored base charge from the upper output driver transistor and to supply base current derived from the load to the lower output driver transistor during high to low transitions of the output voltage.

Abstract: A base drive inhibit circuit for positive and negative phase transistors of a switching amplifier. The circuit comprises a pair of comparators for comparing the voltage between the collector and emitter elements of the transistors with an appropriate reference voltage, and provides a signal to supply base drive voltage, when their associated output transistor is in a forward biased state and the level of reference voltage is less than the level of voltage between the collector and emitter. A logic control circuit supplies base drive voltage to one of the transistors when both a drive signal from an external source is in a proper polarity state and the output signal from the comparator indicates that the transistor is in a forward biased state.A timer is provided to delay base drive voltage to either transistor when the base drive signal is in a transition between polarity states.