14results about "DC-isolation amplifier" patented technology

Embodiments of an interface circuit, a MicroElectroMechanical system (MEMS) interface circuit, and a method for operating an interface circuit are disclosed. In an embodiment, an interface circuit includes an input chopper circuit configured to apply an excitation voltage to a transducer by pre-charging the transducer with bias voltages in alternating sensing cycles to generate a transducer difference charge, an input common-mode control circuit configured to generate a common-mode voltage in response to the applied excitation voltage, and a capacitance-to-voltage (C / V) and output chopper circuit configured to, in response to the common-mode voltage, integrate transducer difference charge on capacitors to produce an output voltage.

To provide a circuit structure capable of improving reliability of a power line communication.SOLUTION: A circuit structure includes a power line, and an electric energy wave and a network signal are transmitted onto the power line. The circuit structure contains: a first isolator 201; and a first coupler 202. The first isolator is arranged to each power consumption end E of the circuit structure or an inlet of a part of the power consumption end, separates the power line into the power consumption end and a transmission end T, and is used for removing the network signal so that the electric energy wave is entered into the power consumption end. The first coupler is used for generating a first coupling path P1, the network signal does not pass the first isolator by the first coupling path, and enters into the transmission end via the first coupling path.SELECTED DRAWING: Figure 2B

Isolated circuit systems are provided. The systems include a primary side circuit and a secondary circuit, electrically isolated from each other. The primary side and secondary side circuits each utilize a direct current (DC) reference signal. The primary side circuit may use the DC reference signal in a modulation operation. The secondary side circuit may use the DC reference signal in a demodulation operation. The DC reference signal may be sent from the primary side circuit to the secondary side circuit, or from the secondary side circuit to the primary side circuit.

A charge amplifier circuit (10) for a capacitive sensing arrangement (80), the charge amplifier circuit (10) including: an first amplifier stage (20) including a first amplifier input (22), a second amplifier input (23) connectable to the capacitive sensing arrangement (80), and including a first amplifier output (24) and a second amplifier output (25), a second amplifier stage (30) including a first amplifier input (32), a second amplifier input (33), a first amplifier output (34) and a second amplifier output (35), and a switched capacitor arrangement (40) between the first amplifier stage (20) and the second amplifier stage (30), the switched capacitor arrangement (40) including a first integration capacitor (42), a second integration capacitor (43), a number of first switches (66, 67) and a number of second switches (68, 69).

A circuit structure to improve reliability of power line communication has a power line, on which a power energy wave and a network signal are transmitted. The circuit structure includes: a first isolator, which is disposed at an entrance of a power consumption terminal of the circuit structure, separates the power line into the power consumption terminal and a transmission terminal, and filters the network signal, so that the power energy wave enters the power consumption terminal; and a first coupler for generating a first coupling path, through which the network signal enters the transmission terminal via the first coupler without passing through the first isolator. Power line impedance at a side of the transmission terminal is not affected by a side of the power consumption terminal.

The present invention is a Class-D amplifier including: a capacitively-coupled amplifier, configured to receive an input signal and a feedback signal and generate an error signal; and a loop filter, coupled to input capacitor and the feedback capacitor, configured to generate a processed signal according to the error signal; and a pulse-width modulation (PWM) generator, coupled to the loop filter, configured to generate a plurality of PWM signals according to the processed signal and a control signal; and a voltage boosting power stage, coupled to the PWM generator, configured to generate a boosted output signal according to the plurality of PWM signals, the control signal and a power supply, and to feedback the boosted output signal to the loop filter, wherein the maximum voltage of the boosted output signal is greater than the voltage of the power supply.

Provided is a semiconductor circuit that includes a plurality of amplifiers that is connected in series and individually amplify and supply a signal on an input side to an output side. A first chopper switch is connected to an input side of a first amplifier connected first among the plurality of amplifies, and a second chopper switch is connected to an output side of the first amplifier. The first and second chopper switches act in synchronism with a first chopper clock. A third chopper switch is connected to an input side of a second amplifier, and a fourth chopper switch is connected to an output side of the second amplifier. The third and fourth chopper switches act in synchronism with a second chopper clock. A phase compensation capacitor is connected at one end to an input portion of the third chopper switch.

Embodiments of an interface circuit, a MicroElectroMechanical system (MEMS) interface circuit, and a method for operating an interface circuit are disclosed. In an embodiment, an interface circuit includes an input chopper circuit configured to apply an excitation voltage to a transducer by pre-charging the transducer with bias voltages in alternating sensing cycles to generate a transducer difference charge, an input common-mode control circuit configured to generate a common-mode voltage in response to the applied excitation voltage, and a capacitance-to-voltage (C / V) and output chopper circuit configured to, in response to the common-mode voltage, integrate transducer difference charge on capacitors to produce an output voltage.

Extended dynamic range of a Micro-Electro-Mechanical System (MEMS) microphone circuit is accomplished in low-noise amplifier circuits and their methods of operation. The circuits are amplifier circuits receive an input signal from a MEMS microphone, and include an input terminal for connection the microphone, a low-noise amplifier having an input coupled to the input terminal, and a capacitively-coupled instrumentation amplifier (CCIA) having an input coupled to an output of the low-noise amplifier. The circuit also includes at least one additional signal path having inputs coupled to the output of the low-noise amplifier and that bypasses the CCIA to provide an alternative signal path, and a switching circuit for clamping the inputs of the CCIA to a common-mode voltage of the circuit while the signal level is greater than the threshold signal level.

Methods and devices for termination of an envelope frequency and harmonics in an RF amplifier are presented. A multifunctional filter is coupled to an RF node of the RF amplifier to provide first and second conduction paths between the RF node and first / second low impedance nodes. The first conduction path provides a low impedance at the envelope frequency and high impedances at an operating frequency of the RF amplifier and corresponding higher order harmonics. The second conduction path provides a low impedance at the higher order harmonics and high impedances at the envelope frequency and at the operating frequency. The multifunctional filter includes first / second inductors in series connection between the RF node and the first low impedance node. According to one aspect, the first / second inductors are coupled to first / second capacitors to respectively form a tank circuit and a trap circuit operating at the frequencies of the harmonics.

A system and method for a drift reset circuit for updating the input offset voltage in an ionization smoke detector are disclosed. The method may include monitoring an ionization chamber of a smoke detector for an alert. The method may also include periodically powering on a drift reset circuit to update an input offset voltage of an operational amplifier. The method may additionally include outputting the input offset voltage to the operational amplifier. The method may further include powering off the drift reset circuit.

Described embodiments include an apparatus with a first amplifier having first inputs and first outputs. A second amplifier has second inputs and a second output. A first chopper circuit is coupled between third inputs and the first inputs. A second chopper circuit is coupled between the first outputs and the second inputs. A balanced filter is coupled to the second inputs.

An asymmetrical power amplifier circuit is provided. The asymmetrical power amplifier circuit includes a carrier amplifier and a peak amplifier. The carrier amplifier is always active to amplify a radio frequency (RF) to a carrier output power, while the peak amplifier is only active to amplify the RF signal to a peak output power when a time-variant output power of the RF signal is higher than a predefined power threshold. The RF signal in the carrier output power is summed with the RF signal in the peak output power to thereby output the amplified RF signal in the time-variant output power. Unlike a conventional symmetrical power amplifier, the carrier output power and the peak output power are different at a peak of the time-variant output power. As such, the carrier amplifier and the peak amplifier can both operate with optimal efficiency based on a same modulated voltage.

A semiconductor device includes a temperature-independent current generator that generates a reference current substantially independent of temperature and a mirror current that is a substantial duplicate of the reference current, a pulse signal generator that samples the mirror current so as to generate a pulse signal, and a counter that obtains a number of pulse signals generated by the pulse signal generator, that permits the pulse signal generator to generate a pulse signal when it is determined thereby that the number of pulse signals obtained thereby is less than a predetermined threshold value, and that inhibits the pulse signal generator from generating a pulse signal when it is determined thereby that the number of pulse signals obtained thereby is equal to the predetermined threshold value. A method for monitoring a temperature of the semiconductor device is also disclosed.