11results about "Volume compression/expansion having semiconductor devices" patented technology

Aspects of the subject disclosure may include, for example, first and second operational amplifiers; and a differential pair of NPN transistors in a feedback path of the TLA configured to convert an input current signal into an output voltage signal, where a first emitter of a first NPN transistor of the pair of NPN transistors is connected to an inverting input of the first operational amplifier, and where a second emitter of a second NPN transistor of the pair of NPN transistors is connected to a non-inverting input of the second operational amplifier. Other embodiments are disclosed.

An example detector cell includes a first current source circuit having a terminal. The detector cell includes a first transistor having a control terminal, a first terminal, and a second terminal coupled to the terminal of the first current source circuit. The detector cell includes a second current source circuit having a terminal coupled to the first terminal of the first transistor. The detector cell includes a first current mirror having a first terminal and a second terminal, the first terminal coupled to the terminal of the second current source circuit and the first terminal of the first transistor. The detector cell includes a second transistor having a control terminal, a first terminal, and a second terminal coupled to the terminal of the first current source circuit. The detector cell includes a third current source circuit having a terminal coupled to the first terminal of the second transistor. The detector cell includes a second current mirror having a first terminal coupled to the terminal of the third current source circuit and the first terminal of the second transistor and a second terminal coupled to the second terminal of the first current mirror.

This application relates to methods and apparatus for clipping prevention. A driver apparatus for driving a load with an output signal has a switching driver with a switch network and a modulator configured to control the switch network to switch output nodes between different switching voltages with a controlled duty-cycle. A quantizer controller receives a quantizer input signal based on an input signal and a feedback signal and controls the duty-cycle of the switch network. A clipping prevention controller is configured to control a gain applied to the input signal so as to provide limiting of the input signal to avoid clipping, wherein the clipping prevention controller is configured to dynamically control at least one limiting threshold used to determine when to apply limiting of the input signal based on an indication of said quantizer input signal.

This application relates to methods and apparatus for voltage monitoring of switching drivers. A modulator is configured to receive a modulator input signal and to controlling switching of an output stage of the switching driver to generate a first drive signal. A voltage monitor is configured to receive a first digital signal tapped from the modulator and to generate an indication of output voltage of the first drive signal from the first digital signal by controllably applying an adjustment from the first digital signal to compensate for inaccuracy between the first digital signal and the output voltage. The adjustment is based on monitored operation of the modulator. In some cases the monitored operation may be clipping of the switching driver. In some cases the monitored operation may be a signal generated by the modulator that include a contribution from a feedback signal of output voltage.

An audio system is provided. The aspects include a notification appliance circuit (NAC) having one or more speakers configured to reproduce sound. The aspects include an amplifier circuit configured to drive the one or more speakers. The aspects include a relay circuit configured to selectively connect or disconnect the speakers to or from the amplifier circuit responsive to an enable amplifier control signal or a disable amplifier control signal, respectively. The aspects include a logic element configured to generate the enable amplifier control signal or the disable amplifier control signal responsive to an absence or a presence of an overcurrent condition in an output of the amplifier circuit, respectively. The aspects include an overcurrent detection circuit configurated to detect the absence or the presence of the overcurrent condition.

The disclosure relates to a current converter circuit (600) for converting a linear input current (lctrl_lin) to an exponential output current (lctrl_sum), the current converter circuit (600) comprising first and second current converters (601, 602), each of which comprises: an input current branch (6031, 6032) with an input current source (6041, 6042) connected in series with a tuning voltage circuit (6051, 6052) and a tuning resistor (6061, 6062) between a supply voltage line (607) and a common voltage line (608); and an output current branch (6091, 6092) with an output transistor (6101, 6102) having a collector connected to an output node (6111, 6112), a emitter connected to the common voltage line (608) and a base connected to the tuning voltage circuit (6051, 6052), wherein the output nodes (6111, 6112) of the first and second current converters (601, 602) are connected to a summing output node (612) of the current converter circuit (600).

A logarithmic amplifier (200) includes a logarithmic current preamplifier circuit (202) and a logarithmic amplifier circuit (204). The logarithmic current preamplifier circuit (202) includes an inverting input terminal (206A), an output terminal (206B), and a first diode (210). The first diode (210) is coupled between the inverting input terminal (206A) and the output terminal (206B) of the logarithmic current preamplifier circuit (202). The logarithmic amplifier circuit (204) includes an inverting input terminal (212A), an output terminal (212B), and a second diode (214). The inverting input terminal (212A) of the logarithmic amplifier circuit (204) is coupled to the output terminal (212B) of the logarithmic current preamplifier circuit (202). The second diode (214) is coupled between the inverting input terminal (212A) and the output terminal (212B) of the logarithmic amplifier circuit (204).

The disclosure relates to a current converter circuit. Example embodiments include a current converter circuit (600) for converting a linear input current (Ictrl_lin) to an exponential output current (Ictrl_sum), the current converter circuit (600) comprising first and second current converters (601, 602), each of which comprises: an input current branch (6031, 6032) with an input current source (6041, 6042) connected in series with a tuning voltage circuit (6051, 6052) and a tuning resistor (6061, 6062) between a supply voltage line (607) and a common voltage line (608); and an output current branch (6091, 6092) with an output transistor (6101, 6102) having a collector connected to an output node (6111, 6112), a emitter connected to the common voltage line (608) and a base connected to the tuning voltage circuit (6051, 6052), wherein the output nodes (6111, 6112) of the first and second current converters (601, 602) are connected to a summing output node (612) of the current converter circuit (600)

The invention relates to a method for protecting a component (6) within an audio device (4) from the exceedance of a maximum internal temperature (TI), wherein a power loss (V) of the component (6) is determined, a measurement temperature (TM) is measured on the component (6), a temperature difference (DT) for the component (6) between the measurement temperature (TM) on the component and the internal temperature (TI) is determined from the power loss (V) by means of a thermal model (14) of the component (6), the internal temperature (TI) is determined as the sum of the measurement temperature (TM) and the temperature difference (DT), a permissible maximum value (VM) for the power loss (V) is determined on the basis of the internal temperature (TM) and known component data (16) of the component (6), and the component (6) is operated in a normal operating mode (N) if the power loss (V) does not exceed the maximum value (VM) or the component (6) is otherwise operated in reduced-power economy operating mode (S) such that the power loss (V) is limited to the maximum value (VM). An audio apparatus (2), having an audio device (4) that internally contains a component (6) that should be protected from the exceedance of a maximum internal temperature (TI), contains a protection module (8) for carrying out the method according to the invention.

Method for adjusting the dynamic range of a receiver amplifier (100) in an environmental sensor device, comprising the step of injecting (S200) an additional electrical signal (S g ) into the input (11, 12) of the receiving amplifier (100) to reduce an output signal generated due to a first electrical signal (u a ) of the receiving amplifier (100), wherein the additional electrical signal (S g ) by a current source (ig, B) drives a current towards a negative terminal of an operational amplifier (1) inside the receiver amplifier (100) and / or a voltage source (ug, A) is driven to couple a voltage to the positive terminal of the operational amplifier (1) of the receiver amplifier (100).