摘要:
Die Erfindung betrifft eine Anordnung (1) zur Kompensation einer Offset-Spannung (U off ) eines elektronischen Verstärkers (2), umfassend - einen elektronischen Verstärker (2) mit einem ersten Eingang (E+), einem zweiten Eingang (E-), einem ersten Ausgang (A+) und einem zweiten Ausgang (A-), - einem Eingangsschaltmittel (10), - einem Ausgangsschaltmittel (20), - einer Steuerschaltung (30),
wobei die Eingangsschaltmittel (10) derart zwischen einem Signaleingang (X) und dem ersten Eingang (E+) und dem zweiten Eingang (E-) angeordnet sind, dass in einem ersten Schaltzustand (Z1) der erste Eingang (E+) mit dem Signaleingang (X) verbunden ist und in einem zweiten Schaltzustand (Z2) der zweite Eingang (E-) mit dem Signaleingang (X) verbunden ist, und wobei die Ausgangsschaltmittel (20) derart zwischen einem Signalausgang (Y) angeordnet sind, dass in dem ersten Schaltzustand (Z1) der erste Ausgang (A+) mit dem Signalausgang (Y) verbunden ist und in dem zweiten Schaltzustand (Z2) der zweite Ausgang (A-) mit dem Signalausgang (Y) verbunden ist, und wobei die Steuerschaltung (30) ausgestaltet ist das Eingangsschaltmittel (10) und das Ausgangsschaltmittel (20) synchron in den ersten Schaltzustand (Z1) bzw. in den zweiten Schaltzustand (Z2) zu schalten.
摘要:
An amplifier system is described. The amplifier system may amplify an audio signal transmitted via a connected loudspeaker in a first mode of operation. In a second mode of operation the amplifier system may amplify a signal generated by the loudspeaker operated in reverse as a microphone. Because a loudspeaker is less sensitive than a microphone the amplifier system may be used to acquire audio at high sound pressure levels for example at a concert or while making a phone-call in a noisy environment for example with a high level of wind noise.
摘要:
An amplifier system is described. The amplifier system may amplify an audio signal transmitted via a connected loudspeaker in a first mode of operation. In a second mode of operation the amplifier system may amplify a signal generated by the loudspeaker operated in reverse as a microphone. Because a loudspeaker is less sensitive than a microphone the amplifier system may be used to acquire audio at high sound pressure levels for example at a concert or while making a phone-call in a noisy environment for example with a high level of wind noise.
摘要:
A chopper amplifier includes a chopper modulator to modulate a certain detection signal and a bias voltage by a certain control signal and output a chopper modulation signal, a first differential amplifier to differentially amplify the chopper modulation signal from the chopper modulator and output a differential modulation signal, a chopper demodulator to demodulate the differential modulation signal from the first differential amplifier by the control signal and output a demodulation signal, a second differential amplifier to extract a detection signal component from the demodulation signal, and a plurality of filters connected at an input terminal of the second differential amplifier and having different cutoff frequencies from each other relative to the demodulation signal.
摘要:
In a mixed analog and digital integrated circuit for physiological signal instrumentation such as electrocardiographs, electromyographs, and electroencephalographs, an electronic differential amplifier comprises a chopper-stabilised first stage amplifier (402, 408, 412), a second stage amplifier (414) providing a negative output (418) and a positive output (416) to a chopper-stabilised feedback circuit (434-444), and a gain feedback circuit (420) which receives the negative output (418) and supplies a gain feedback voltage (24) to the first stage amplifier. The integrated circuit has five signal channels, each with analog amplification and analog to digital conversion. The channels can be configured for various combinations of input signal amplification, input signal summation, analog output driving, and AC impedance measurement. The integrated circuit has two digital serial input lines and two digital serial output lines, all designed for direct connection to optical couplers. Channel configuration, gain, and other parameters are externally controllable by a serial digital input signal. Up to six compatible devices can be serially connected in a chain.
摘要:
In a mixed analog and digital integrated circuit for physiological signal instrumentation such as electrocardiographs, electromyographs, and electroencephalographs, an electronic differential amplifier comprises a chopper-stabilised first stage amplifier (402, 408, 412), a second stage amplifier (414) providing a negative output (418) and a positive output (416) to a chopper-stabilised feedback circuit (434-444), and a gain feedback circuit (420) which receives the negative output (418) and supplies a gain feedback voltage (24) to the first stage amplifier. The integrated circuit has five signal channels, each with analog amplification and analog to digital conversion. The channels can be configured for various combinations of input signal amplification, input signal summation, analog output driving, and AC impedance measurement. The integrated circuit has two digital serial input lines and two digital serial output lines, all designed for direct connection to optical couplers. Channel configuration, gain, and other parameters are externally controllable by a serial digital input signal. Up to six compatible devices can be serially connected in a chain.
摘要:
The invention provides an RF detection circuit and method using an envelope detector having an output connected to a first input of a differential amplifier and a reference storage capacitor to a second input of the differential amplifier. In a preferred implementation of the calibration mode, there is initial discharging of a reference storage capacitor, high speed charging of the reference storage capacitor until the differential amplifier output toggles, then slower discharging of the reference storage capacitor until the differential amplifier output toggles again. The resulting voltage is stored on the reference storage capacitor for use in a subsequent detection mode. This provides storage of an offset voltage which calibrates both the envelope detector differential amplifier functions.
摘要:
Provided is system for an improved programmable gain amplifier (PGA). The system includes an amplifier and a first gain control mechanism. The first gain control mechanism includes a circuit input port and is positioned along a feedback path of the amplifier. The first gain control mechanism is configured to (i) receive an input signal and (ii) moderate gains applied to the received input signal, the applied gains including gain values of greater than or equal to one. A second gain control mechanism is coupled to the first gain control mechanism and is integrated with a function of the amplifier. The second gain control mechanism (i) provides gain values of less than one and (ii) decreases a feedback factor of the amplifier when the gain values are provided having values of less than one.