公开(公告)号：IT1268473B1

公开(公告)日：1997-03-04

申请号：ITVA930023

申请日：1993-10-22

Applicant: ST MICROELECTRONICS SRL

Inventor： FAGNANI MAURO ,  FERRARIO BRUNO ,  SANDRI PAOLO

IPC: H03F1/00 ,  H03F3/343 ,  H03F1/30

Abstract: A circuit for regulating the time of charging of the output node of an amplifier at start up, commonly comprising an external soft-start capacitor charged by a current delivered by a pull-up transistor (QG19) of a push-pull output stage of the amplifier, through a decoupling diode (QG23) that is functionally connected between the output node of the amplifier and an armature of the external soft-start capacitor, is provided with a current mirror feed back circuit capable of mirroring a current function of the charge current of the external soft-start capacitor on the driving node of the pull-up transistor (QG19) of the output stage of the amplifier. The regulating circuit permits to use an external capacitance of extremely small size and upon the reaching of a fully charged condition by the external capacitor, the control circuit self-isolates and does not influence in any way the normal operation of the amplifier.

公开(公告)号：ITVA930023D0

公开(公告)日：1993-10-22

申请号：ITVA930023

申请日：1993-10-22

Applicant: ST MICROELECTRONICS SRL

Inventor： FAGNANI MAURO ,  FERRARIO BRUNO ,  SANDRI PAOLO

IPC: H03F3/343 ,  H03F1/00 ,  H03F1/30

Abstract: A circuit for regulating the time of charging of the output node of an amplifier at start up, commonly comprising an external soft-start capacitor charged by a current delivered by a pull-up transistor (QG19) of a push-pull output stage of the amplifier, through a decoupling diode (QG23) that is functionally connected between the output node of the amplifier and an armature of the external soft-start capacitor, is provided with a current mirror feed back circuit capable of mirroring a current function of the charge current of the external soft-start capacitor on the driving node of the pull-up transistor (QG19) of the output stage of the amplifier. The regulating circuit permits to use an external capacitance of extremely small size and upon the reaching of a fully charged condition by the external capacitor, the control circuit self-isolates and does not influence in any way the normal operation of the amplifier.

公开(公告)号：IT1313865B1

公开(公告)日：2002-09-24

申请号：ITMI992361

申请日：1999-11-11

Applicant: ST MICROELECTRONICS SRL

Inventor： CAMERA ALESSANDRO ,  BELLOMO IGNAZIO ,  SANDRI PAOLO

IPC: G11C29/50

公开(公告)号：ITMI992361D0

公开(公告)日：1999-11-11

申请号：ITMI992361

申请日：1999-11-11

Applicant: ST MICROELECTRONICS SRL

Inventor： CAMERA ALESSANDRO ,  BELLOMO IGNAZIO ,  SANDRI PAOLO

IPC: G11C29/50

公开(公告)号：DE69413638T2

公开(公告)日：1999-02-25

申请号：DE69413638

申请日：1994-07-25

Applicant: ST MICROELECTRONICS SRL

Inventor： FAGNANI MAURO ,  FERRARIO BRUNO ,  SANDRI PAOLO

IPC: H03F1/00 ,  H03F1/30 ,  H03F3/343

Abstract: A circuit for regulating the time of charging of the output node of an amplifier at start up, commonly comprising an external soft-start capacitor charged by a current delivered by a pull-up transistor (QG19) of a push-pull output stage of the amplifier, through a decoupling diode (QG23) that is functionally connected between the output node of the amplifier and an armature of the external soft-start capacitor, is provided with a current mirror feed back circuit capable of mirroring a current function of the charge current of the external soft-start capacitor on the driving node of the pull-up transistor (QG19) of the output stage of the amplifier. The regulating circuit permits to use an external capacitance of extremely small size and upon the reaching of a fully charged condition by the external capacitor, the control circuit self-isolates and does not influence in any way the normal operation of the amplifier.

公开(公告)号：ITVA930022A1

公开(公告)日：1995-04-24

申请号：ITVA930022

申请日：1993-10-22

Applicant: ST MICROELECTRONICS SRL

Inventor： BORGHI MARIA ROSA ,  SANDRI PAOLO

IPC: H02M3/155 ,  G05F1/575 ,  H02M3/156

Abstract: A buck converter comprises a PWM regulation loop and a hysteretic control loop, which are alternatively enabled by a mode selection circuit of the converter in function of the load level. When the level of load drops below a preset limit as referred to a design load level, the converter passes from a PWM control mode to a hysteretic control mode, thus eliminating switching losses during periods of operation at relatively low load level.

公开(公告)号：ITVA930022D0

公开(公告)日：1993-10-22

申请号：ITVA930022

申请日：1993-10-22

Applicant: ST MICROELECTRONICS SRL

Inventor： BORGHI MARIA ROSA ,  SANDRI PAOLO

IPC: H02M3/155 ,  G05F1/575 ,  H02M3/156

Abstract: A buck converter comprises a PWM regulation loop and a hysteretic control loop, which are alternatively enabled by a mode selection circuit of the converter in function of the load level. When the level of load drops below a preset limit as referred to a design load level, the converter passes from a PWM control mode to a hysteretic control mode, thus eliminating switching losses during periods of operation at relatively low load level.