The present disclosure relates to a semiconductor apparatus and a potential measuring apparatus capable of preventing deterioration in signal characteristics due to parasitic capacitance caused by providing a configuration for realizing an electrode plating process when an electrode and an amplifier are provided on the same substrate. When a power source supplies a potential necessary for plating processing and a breaker reads a signal from liquid, and an amplifier amplifies and outputs the signal, the power source required for the plating processing is blocked with respect to the electrode. This is applicable to the potential measuring apparatus.

An apparatus comprising: a cascode arrangement comprising two or more transistors, the cascode arrangement coupled between a supply voltage terminal for receiving a supply voltage from a battery and a ground terminal, and a bias voltage generator configured to provide a bias voltage to at least one of the two or more transistors of the cascode arrangement to bias the cascode arrangement, the bias voltage generator further configured to increase the bias voltage with increasing supply voltage at a first rate over a first supply voltage range and increase the bias voltage with increasing supply voltage at a second rate, greater than the first rate, over a second supply voltage range, wherein the second supply voltage range comprises a range of voltages greater than the first supply voltage range.

An audio amplifier system is described herein, comprising: an amplifier adapted to amplify an audio signal and comprising an output enable/disable input, the amplifier further adapted to receive an output enable signal at the output enable/disable input that enables/disables an output of the amplifier; a Zobel network connected to the output of the audio amplifier and comprising a Zobel capacitor and a Zobel resistor arranged such that they form a high pass frequency filter function and wherein the Zobel network is adapted to be substantially resistive when a frequency of an audio signal output from the audio amplifier is within a first frequency range; a mirroring resistor connected in parallel to the Zobel resistor and adapted to mirror a power that is dissipated in the Zobel resistor, and wherein a printed circuit board upon which the mirroring resistor is located is adapted to conduct heat generated by the mirroring resistor; a negative temperature coefficient (NTC) resistor located in close proximity to the mirroring resistor to receive the conducted heat from the mirroring resistor and which is adapted to change its resistance in response to the transferred heat such that its resistance goes down as a temperature of the NTC resistor increases; and a circuit adapted to generate the output enable signal, wherein the circuit generates an output enable signal that enables the output of the amplifier when the temperature of the Zobel resistor is below a first temperature, and wherein the circuit generates an output enable signal that disables the output of the amplifier when the temperature of the Zobel resistor is substantially the same or above the first temperature.

A power amplifier includes an over-current protection loop and/or an over-voltage protection loop to assist in preventing operation outside a safe operation zone. In a further exemplary aspect, triggering of the over-current protection loop adjusts a threshold voltage for the over-voltage protection loop. In further exemplary aspects, the over-current protection loop may adjust not only a bias regulator, but also provide an auxiliary control signal that further limits signals reaching the power amplifier. In still further exemplary aspects, the over-voltage protection loop may operate independently of the over-current protection current loop or the over-voltage protection loop contribute to an over-current protection signal.

A power amplifier includes an over-current protection loop and/or an over-voltage protection loop to assist in preventing operation outside a safe operation zone. In a further exemplary aspect, triggering of the over-current protection loop adjusts a threshold voltage for the over-voltage protection loop. In further exemplary aspects, the over-current protection loop may adjust not only a bias regulator, but also provide an auxiliary control signal that further limits signals reaching the power amplifier. In still further exemplary aspects, the over-voltage protection loop may operate independently of the over-current protection current loop or the over-voltage protection loop contribute to an over-current protection signal.

A power amplifier includes an over-current protection loop and/or an over-voltage protection loop to assist in preventing operation outside a safe operation zone. In a further exemplary aspect, triggering of the over-current protection loop adjusts a threshold voltage for the over-voltage protection loop. In further exemplary aspects, the over-current protection loop may adjust not only a bias regulator, but also provide an auxiliary control signal that further limits signals reaching the power amplifier. In still further exemplary aspects, the over-voltage protection loop may operate independently of the over-current protection current loop or the over-voltage protection loop contribute to an over-current protection signal.

A power amplifier includes an over-current protection loop and/or an over-voltage protection loop to assist in preventing operation outside a safe operation zone. In a further exemplary aspect, triggering of the over-current protection loop adjusts a threshold voltage for the over-voltage protection loop. In further exemplary aspects, the over-current protection loop may adjust not only a bias regulator, but also provide an auxiliary control signal that further limits signals reaching the power amplifier. In still further exemplary aspects, the over-voltage protection loop may operate independently of the over-current protection current loop or the over-voltage protection loop contribute to an over-current protection signal.

An overcurrent protection circuit includes: a first transistor and a second transistor configured to form an amplifier input stage that receives input of a detection signal according to a monitoring target current; and a third transistor configured to form an amplifier output stage that generates a current output signal according to a difference between the detection signal and a reference signal and causes the current output signal to be negatively fed back to the amplifier input stage, wherein the monitoring target current is limited based on the current output signal output from the third transistor.

A class-D amplifier having an output driver with a first, second, and third driver, the output driver having a first output coupled to the first and third drivers, a second output coupled to the second driver; a sensing resistor coupled in series between the first driver and the first output; and a pulse width modulation (PWM) controller coupled to the inputs of the drivers and configured to receive an audio input signal; control a PWM generator to generate a first pulse signal and a second pulse signal based on the audio input signal and a power supply input; determine a voltage drop across the sensing resistor; and, responsive to the voltage drop being greater than a threshold, sequence control of the first pulse signal to the first driver and switch a voltage at the first driver to an increased voltage based on the voltage drop.

Methods and apparatus for limiting the input voltage (swing) of a power amplifier, such as a power amplifier in a radio frequency (RF) front-end of a wireless device. One example radio frequency front-end circuit generally includes a power amplifier, a matching circuit having an output coupled to an input of the power amplifier, and an overvoltage protection circuit coupled to the matching circuit. With an overvoltage protection circuit coupled to the matching circuit in this manner, the power amplifier may have enhanced ruggedness performance.