公开(公告)号：DE69920404T2

公开(公告)日：2005-10-06

申请号：DE69920404

申请日：1999-05-14

Applicant: ST MICROELECTRONICS SRL

Inventor： NICOLLINI GERMANO ,  PERNICI SERGIO

IPC: H04R3/00 ,  H03G3/34 ,  H04M1/00 ,  H04M1/60 ,  H04M1/72

公开(公告)号：DE69917767T2

公开(公告)日：2005-06-02

申请号：DE69917767

申请日：1999-07-20

Applicant: ST MICROELECTRONICS SRL

Inventor： PERNICI SERGIO ,  NICOLLINI GERMANO

IPC: H03H19/00 ,  H03F1/00 ,  H03F3/45 ,  H03F3/72 ,  H03G3/34 ,  H04B1/10 ,  H04M1/253 ,  H04M1/60

Abstract: The receiver portion comprises a differential amplifier stage (12) with a single output, an electroacoustic transducer (13) connected between the output, via a capacitor (Cest), and ground and a unit (20) for controlling switching on/off, connected to the differential stage (12) for the activation or deactivation thereof. To prevent annoying noises in the transducer upon switching on and off, the differential stage comprises an operational amplifier (16) having a first capacitor (C1) and a second capacitor (C2) in series with the inverting and the non-inverting input terminals, a third capacitor (C3) connected between the inverting input and the output of the operational amplifier (16), a fourth capacitor (C4) connected between the non-inverting input and a first reference-voltage terminal (ground), a first switching capacitor (C1S) connectible alternatively between a second and a third reference-voltage terminal (RF2, RF3) or between the first input and the output of the operational amplifier (16), a second switching capacitor (C2S) connectible alternatively between a fourth and a fifth reference-voltage terminal (RF4, RF5) or between the second input of the operational amplifier (16) and the fifth reference-voltage terminal (RFS). A switching unit (15) comprises switching means (15a, 15b) controlled by the unit (20) for controlling switching on/off in order to interrupt the connection between the input terminals of the differential stage (12) and the outputs of the previous stage (11) and to connect the differential input terminals (INP1, INP2) to one another for a predetermined period of time ( DELTA t) which starts from the activation of the differential stage (12).

公开(公告)号：DE69917767D1

公开(公告)日：2004-07-08

申请号：DE69917767

申请日：1999-07-20

Applicant: ST MICROELECTRONICS SRL

Inventor： PERNICI SERGIO ,  NICOLLINI GERMANO

IPC: H03H19/00 ,  H03F1/00 ,  H03F3/45 ,  H03F3/72 ,  H03G3/34 ,  H04B1/10 ,  H04M1/253 ,  H04M1/60

Abstract: The receiver portion comprises a differential amplifier stage (12) with a single output, an electroacoustic transducer (13) connected between the output, via a capacitor (Cest), and ground and a unit (20) for controlling switching on/off, connected to the differential stage (12) for the activation or deactivation thereof. To prevent annoying noises in the transducer upon switching on and off, the differential stage comprises an operational amplifier (16) having a first capacitor (C1) and a second capacitor (C2) in series with the inverting and the non-inverting input terminals, a third capacitor (C3) connected between the inverting input and the output of the operational amplifier (16), a fourth capacitor (C4) connected between the non-inverting input and a first reference-voltage terminal (ground), a first switching capacitor (C1S) connectible alternatively between a second and a third reference-voltage terminal (RF2, RF3) or between the first input and the output of the operational amplifier (16), a second switching capacitor (C2S) connectible alternatively between a fourth and a fifth reference-voltage terminal (RF4, RF5) or between the second input of the operational amplifier (16) and the fifth reference-voltage terminal (RFS). A switching unit (15) comprises switching means (15a, 15b) controlled by the unit (20) for controlling switching on/off in order to interrupt the connection between the input terminals of the differential stage (12) and the outputs of the previous stage (11) and to connect the differential input terminals (INP1, INP2) to one another for a predetermined period of time ( DELTA t) which starts from the activation of the differential stage (12).

公开(公告)号：DE69431796D1

公开(公告)日：2003-01-09

申请号：DE69431796

申请日：1994-07-29

Applicant: ST MICROELECTRONICS SRL

Inventor： NICOLLINI GERMANO ,  PERNICI SERGIO

IPC: H03F3/68 ,  H03F3/72 ,  H04R3/00

Abstract: An electronic driver circuit for low-impedance loads, being of a type which comprises an input terminal (IN) to which a voltage signal (Vin) is applied for alternate transfer to an output, and a plurality of output terminals (OUTi), each connected to a corresponding electric load (2), further comprises, between the input terminal and the output terminals, a single operational amplifier (3) having multiple output stages (7), one for each output terminal (OUTi). The operational amplifier (3) is of the single-ended or fully differential multistage type and allows each load to be driven alternately by activation of the corresponding output stage (7).

公开(公告)号：ITMI20002806A1

公开(公告)日：2002-06-24

申请号：ITMI20002806

申请日：2000-12-22

Applicant: ST MICROELECTRONICS SRL

Inventor： NICOLLINI GERMANO ,  PERNICI SERGIO ,  STEVENAZZI FABIO

IPC: G05F3/26 ,  G05F3/30

Abstract: It is described a circuit generating a stable reference voltage with respect to temperature, which circuit is connected between first and second voltage references and comprises at least one current generating circuit adapted to inject a reference current into a resistive element connected between a base terminal of a bipolar transistor and an additional voltage reference. The bipolar transistor is connected between the first and second voltage references and to an output terminal of the generator circuit whereat the stable reference voltage with respect to temperature is. The generator circuit further comprises at least another resistive element, feedback connected between the output terminal of the generator circuit and the base terminal of the bipolar transistor to enable injecting additional current, having reverse dependence on temperature from the reference current, into the resistive element.