2.
    发明专利
    未知

    公开(公告)号:DE69529828D1

    公开(公告)日:2003-04-10

    申请号:DE69529828

    申请日:1995-11-30

    Abstract: An operational amplifier (5) with adjustable frequency compensation comprises a transconductance input stage (2) and an amplifier output stage (3) connected serially together between an input terminal (IN) and an output terminal (OUT) of the operational amplifier. At least one compensation block (6) is connected across the input and the output of said output stage (3), According to the invention, the compensation block (6) comprises a plurality (N) of charge storage elements (CCn) connected in parallel together and in series to a switch block (7) which selectively connects a sub-plurality (N') of said charge storage elements (CCn) across the input and the output of said output stage (3) on the basis of an external signal (SEL) of the amplifier (5).

    3.
    发明专利
    未知

    公开(公告)号:DE69530773D1

    公开(公告)日:2003-06-18

    申请号:DE69530773

    申请日:1995-10-30

    Abstract: The interface circuit described is disposed between a generator (LG) of control signals (CS) and a plurality of electronic switches (SW) in order to produce boosted voltage signals (SCS) corresponding to the control signals (CS) for activating the electronic switches (SW). To avoid the use of capacitors with high capacitance and thus to save area of the integrated circuit, the circuit comprises a generator (SCK) of boosted-voltage clock signals ( phi , phi ) and a plurality of voltage multipliers (VM) each having an input connected to an output of the control signal generator (LG), an output connected to at least one terminal for activating an electronic switch (SW) and two control terminals connected to the boosted-voltage clock-signal generator.

    4.
    发明专利
    未知

    公开(公告)号:DE69529908D1

    公开(公告)日:2003-04-17

    申请号:DE69529908

    申请日:1995-11-30

    Abstract: An operational amplifier frequency self-compensated with respect to closed-loop gain comprises a transconductance input stage (2) and an amplifier output stage (3) connected serially together to receive an input signal (Sin) on at least one input terminal (IN) of the amplifier and generate an amplified signal (Sout) on an output terminal (OUT) of the amplifier. Provided between the input (2) and output (3) stages is an intermediate node (S) which is connected to a compensation block (11) to receive a frequency-variable compensation signal (Sc) therefrom. According to the invention, the compensation block (11) is coupled with its input to the input terminal (IN) of the amplifier. The compensation block (11) is connected to receive at least the feedback signal (Sf). Preferably, the compensation signal (Sc) is variable as a function of a gain value (Gcl) which is determined by the feedback circuit, and said variation of the compensation signal occurs in a relationship of inverse proportionality to the gain value. This invention is useful in discrete circuits whose operational amplifier forms a device by itself, as well as in fully integrated circuits.

    5.
    发明专利
    未知

    公开(公告)号:DE69529908T2

    公开(公告)日:2003-12-04

    申请号:DE69529908

    申请日:1995-11-30

    Abstract: An operational amplifier frequency self-compensated with respect to closed-loop gain comprises a transconductance input stage (2) and an amplifier output stage (3) connected serially together to receive an input signal (Sin) on at least one input terminal (IN) of the amplifier and generate an amplified signal (Sout) on an output terminal (OUT) of the amplifier. Provided between the input (2) and output (3) stages is an intermediate node (S) which is connected to a compensation block (11) to receive a frequency-variable compensation signal (Sc) therefrom. According to the invention, the compensation block (11) is coupled with its input to the input terminal (IN) of the amplifier. The compensation block (11) is connected to receive at least the feedback signal (Sf). Preferably, the compensation signal (Sc) is variable as a function of a gain value (Gcl) which is determined by the feedback circuit, and said variation of the compensation signal occurs in a relationship of inverse proportionality to the gain value. This invention is useful in discrete circuits whose operational amplifier forms a device by itself, as well as in fully integrated circuits.

    7.
    发明专利
    未知

    公开(公告)号:DE69521197T2

    公开(公告)日:2001-11-08

    申请号:DE69521197

    申请日:1995-04-11

    Abstract: The speech circuit described matches the impedance of the telephone line by synthesizing a complex impedance by means of a positive feedback loop comprising a single resistor (11) and cancels out the side tone by means of a subtracter (20') which extracts from the signal (Va) coming from the line a signal (Vb) correlated to the signal to be transmitted. In order to achieve cancellation of the side tone unaffected by the noise produced in the circuits for synthesizing the impedance, the signal (Vb) correlated to the signal to be transmitted is derived by processing the signal present in the resistor (11) at the output of the feedback loop.

    8.
    发明专利
    未知

    公开(公告)号:DE69521197D1

    公开(公告)日:2001-07-12

    申请号:DE69521197

    申请日:1995-04-11

    Abstract: The speech circuit described matches the impedance of the telephone line by synthesizing a complex impedance by means of a positive feedback loop comprising a single resistor (11) and cancels out the side tone by means of a subtracter (20') which extracts from the signal (Va) coming from the line a signal (Vb) correlated to the signal to be transmitted. In order to achieve cancellation of the side tone unaffected by the noise produced in the circuits for synthesizing the impedance, the signal (Vb) correlated to the signal to be transmitted is derived by processing the signal present in the resistor (11) at the output of the feedback loop.

    9.
    发明专利
    未知

    公开(公告)号:ITVA20010048A1

    公开(公告)日:2003-06-23

    申请号:ITVA20010048

    申请日:2001-12-21

    Abstract: An analog input circuit may include a pair of differential transconductance input stages having input nodes connected in parallel and which are fed the analog input signal. One of the differential transconductance stages may have common mode compatibility toward the supply node at the highest potential, and the other stage may have common mode compatibility toward the supply node at the lowest potential. Furthermore, differential output currents of the transconductance input stages may be summed differentially on first and second input nodes of a differential converter stage, which converts the differential current signals to an amplified differential voltage output signal.

    10.
    发明专利
    未知

    公开(公告)号:IT1311075B1

    公开(公告)日:2002-02-28

    申请号:ITMI990458

    申请日:1999-03-05

    Abstract: A fully differential amplifier, in other words one having differential inputs and outputs, is associated with a circuit to regulate the output voltage reference. This circuit contains a resistive divider connected between the output terminals of the differential amplifier, a diode between the intermediate connection of the divider and common bases of load transistors of the differential amplifier, and a current mirror having a first branch connected to a reference voltage generator and a second branch which forms a current generator connected between the common bases of the load transistors and ground. This provides an efficient feedback control system with low power consumption and takes up less space on an integrated circuit.

Patent Agency Ranking