A programmable a fully-differential programmable gain amplifier for reducing distortion, switching transients and interference, and improving bandwidth. In one embodiment, the amplifier includes a programmable gain module, an amplifier coupled to the current mode outputs and a data latch circuit of the programmable gain module, the amplifier configured to apply common mode voltage to the data latch circuit, and a current-to-voltage converter. In one embodiment, the fully-differential programmable gain amplifier controls distortion and switching interference during amplification by sensing common mode signals to produce an error signal, and applying the resulting error signal to the programmable gain module for multiplying digital to analog conversion. Components of the fully-differential programmable gain amplifier provide compensation of distortion caused by nonlinearity of device switches and switch resistance, and can include a floating supply, galvanic isolation of control signals and a common mode voltage controller.

An amplifier arrangement has a first differential stage with a first transistor pair, a second differential stage with a first and a second transistor pair, each pair having a common source connection. The amplifier arrangement further has a first complementary differential stage with a transistor pair having opposite conductivity type, and a second complementary differential stage with a first and a second transistor pair of the complementary conductivity type. The first and the second complementary differential stage are connected symmetrically compared to the first and the second differential stage. The transistors of the second differential stage and the second complementary differential stage are symmetrically connected to form respective first, second, third and fourth current paths. A pair of output terminals is coupled to the first and the fourth current path. Gate terminals of the transistors are coupled to a respective pair of input terminals.

A programmable a fully-differential programmable gain amplifier for reducing distortion, switching transients and interference, and improving bandwidth. In one embodiment, the amplifier includes a programmable gain module, an amplifier coupled to the current mode outputs and a data latch circuit of the programmable gain module, the amplifier configured to apply common mode voltage to the data latch circuit, and a current-to-voltage converter. In one embodiment, the fully-differential programmable gain amplifier controls distortion and switching interference during amplification by sensing common mode signals to produce an error signal, and applying the resulting error signal to the programmable gain module for multiplying digital to analog conversion. Components of the fully-differential programmable gain amplifier provide compensation of distortion caused by nonlinearity of device switches and switch resistance, and can include a floating supply, galvanic isolation of control signals and a common mode voltage controller.

An analog discrete current mode negative feedback amplifier circuit for use with a micro-fused strain gauge is disclosed. The amplifier circuit includes a Wheatstone bridge coupled to a first power supply and a second power supply. The first power supply and the second power supply can be configured such that the periodically alternate between two voltage levels. The Wheatstone bridge can be coupled to a negative feedback amplifier circuit with common mode detection. The amplifier circuit can comprise a differential amplifier with a negative feedback configuration coupled to a common mode amplifier. In addition, the output of each of the amplifiers can be coupled to a common-mode amplifier. In a pressure sensing application, the output of the common mode amplifier serves to output the temperature while the differential amplifiers serve to output the pressure.

An amplifier circuit having improved common mode rejection is provided. This can be achieved by estimating the common mode value of an input signal and using this to adjust a target common mode voltage at the output of the amplifier. This can help avoid the differential gain becoming modified by the common mode voltage.

A magnetic operational amplifier having a differential stage includes a first magnetic field effect transistor MAGFET and a differential signal conditioner, the differential signal conditioner including a load stage, a differential input pair connected to the load stage and a biasing current source connected to the differential input pair; the magnetic field effect transistor MAGFET being connected to the load stage as a second differential input pair and the differential signal conditioner including a second biasing current source connected to the magnetic field effect transistor MAGFET.

A differential amplifier comprises: a long tailed pair transistor configuration comprising a differential pair of transistors and a tail transistor; and a replica circuit configured to vary a feedback current in the replica circuit to match a replica voltage to a reference voltage, wherein varying the feedback current in the replica circuit provides a bias voltage to the tail transistor in the long tailed pair which controls a tail current through the tail transistor to determine a common mode voltage in the long tailed pair.

An amplifier arrangement has a first differential stage with a first transistor pair, a second differential stage with a first and a second transistor pair, each pair having a common source connection. The amplifier arrangement further has a first complementary differential stage with a transistor pair having opposite conductivity type, and a second complementary differential stage with a first and a second transistor pair of the complementary conductivity type. The first and the second complementary differential stage are connected symmetrically compared to the first and the second differential stage. The transistors of the second differential stage and the second complementary differential stage are symmetrically connected to form respective first, second, third and fourth current paths. A pair of output terminals is coupled to the first and the fourth current path. Gate terminals of the transistors are coupled to a respective pair of input terminals.

An audio amplifier includes a loop filter configured to receive a differential input signal pair, a pulse-width modulation (PWM) signal generator configured to generate PWM signals, corresponding to the differential input signal pair, based on signals received from the loop filter, a driver configured to generate an output signal pair based on the PWM signals, a feedback circuit configured to feed back the output signal pair to the loop filter, and a common mode compensation circuit configured to compensate for a fluctuation in a common mode voltage of the fed-back output signal pair. The common mode compensation circuit generates a compensation voltage for each of a plurality of levels of the common mode voltage, and provides the generated compensation voltage to the loop filter.

An amplifier circuit having improved common mode rejection is provided. This can be achieved by estimating the common mode value of an input signal and using this to adjust a target common mode voltage at the output of the amplifier. This can help avoid the differential gain becoming modified by the common mode voltage.