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公开(公告)号：DE69018362D1
公开(公告)日：1995-05-11
申请号：DE69018362
申请日：1990-10-04
Applicant: SGS THOMSON MICROELECTRONICS
Inventor： GARIBOLDI ROBERTO , GOLA ALBERTO
IPC: H02H9/04 , H02H7/20 , H03K19/003 , H02H11/00
Abstract: A negative overvoltage protection circuit for stages having a transistor with collector output and with the emitter connected to a reference voltage line; a diode (D1) for protection against negative overvoltages present on the output (Vout) is arranged between the collector and the output of the stage. In order to give the output of the stage a presettable minimum voltage level, the reference voltage line is set to a preset voltage which differs from the ground voltage. For this purpose, the circuit comprises an operational amplifier (Op) in a voltage-follower configuration, the output whereof is connected to the reference voltage line, a diode (D2) which is connected between the ground and the non-inverting terminal of the operational amplifier (Op), and a current source which is connected between the non-inverting input of the operational amplifier (Op) and a negative supply line (-VEE).
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Patent Agency Ranking
公开(公告)号：DE69213224T2
公开(公告)日：1997-02-20
申请号：DE69213224
申请日：1992-06-25
Applicant: SGS THOMSON MICROELECTRONICS
Inventor： BERTOLINI LUCA , GARIBOLDI ROBERTO
Abstract: A regulator (1) comprising a power element (2) between the input terminal (3) and output terminal (4); and a regulating loop (7) including a differential stage (8) for comparing the output voltage (Vo) of the regulator with a reference voltage (VR) and accordingly driving a gain stage (9) connected to the power element. The output voltage is picked up by the differential stage via a resistive divider (5), the resistance of which varies according to the value of a logic signal at a control input (22). When the resistance of the divider changes, the inputs of the differential stage (8) are so unbalanced as to produce an output voltage up or down ramp equal to the slew rate of the regulating loop (7) and proportional to the bias current of the differential stage. Over the up ramp, the shorting protection circuit (17) is turned off for a predetermined time tau , whereas, over the down ramp, a stage (28) is turned on for absorbing the discharge current of the capacitive load.
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公开(公告)号：DE69021481D1
公开(公告)日：1995-09-14
申请号：DE69021481
申请日：1990-10-04
Applicant: SGS THOMSON MICROELECTRONICS
Inventor： GARIBOLDI ROBERTO , GOLA ALBERTO
Abstract: A negative overvoltage protection circuit for an insulated vertical PNP transistor (QP) the emitter whereof defines the input (VIN), the collector whereof defines the output (VOUT) and the base whereof is connected to an NPN driving transistor (QN). In order to maximally extend the negative overvoltage which can be applied to the output, the protection circuit comprises an output voltage sensor (R4), a voltage reference (VB), a comparator (Q2,Q3,D1) which is connected in input to the voltage reference (VB) and to the sensor (R4) and generates in output an activation signal when the output voltage of the PNP transistor (QP) becomes smaller than the reference, a switch (Q5) which is controlled by the comparator (Q2,Q3,D1) to switch off the NPN driving transistor (QP) upon the reception of the activation signal and a low-impedance circuit (Q4) which is connected between the emitter and the base of the insulated vertical PNP transistor (QP) and is activated by the activation signal, in a manner suitable for bringing the insulated vertical PNP transistor (QP) practically to BVCBO.
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公开(公告)号：IT8921966D0
公开(公告)日：1989-10-09
申请号：IT2196689
申请日：1989-10-09
Applicant: SGS THOMSON MICROELECTRONICS
Inventor： GARIBOLDI ROBERTO , GOLA ALBERTO
Abstract: A negative overvoltage protection circuit for stages having a transistor with collector output and with the emitter connected to a reference voltage line; a diode (D1) for protection against negative overvoltages present on the output (Vout) is arranged between the collector and the output of the stage. In order to give the output of the stage a presettable minimum voltage level, the reference voltage line is set to a preset voltage which differs from the ground voltage. For this purpose, the circuit comprises an operational amplifier (Op) in a voltage-follower configuration, the output whereof is connected to the reference voltage line, a diode (D2) which is connected between the ground and the non-inverting terminal of the operational amplifier (Op), and a current source which is connected between the non-inverting input of the operational amplifier (Op) and a negative supply line (-VEE).
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公开(公告)号：IT8921965D0
公开(公告)日：1989-10-09
申请号：IT2196589
申请日：1989-10-09
Applicant: SGS THOMSON MICROELECTRONICS
Inventor： GARIBOLDI ROBERTO , GOLA ALBERTO
Abstract: A negative overvoltage protection circuit for an insulated vertical PNP transistor (QP) the emitter whereof defines the input (VIN), the collector whereof defines the output (VOUT) and the base whereof is connected to an NPN driving transistor (QN). In order to maximally extend the negative overvoltage which can be applied to the output, the protection circuit comprises an output voltage sensor (R4), a voltage reference (VB), a comparator (Q2,Q3,D1) which is connected in input to the voltage reference (VB) and to the sensor (R4) and generates in output an activation signal when the output voltage of the PNP transistor (QP) becomes smaller than the reference, a switch (Q5) which is controlled by the comparator (Q2,Q3,D1) to switch off the NPN driving transistor (QP) upon the reception of the activation signal and a low-impedance circuit (Q4) which is connected between the emitter and the base of the insulated vertical PNP transistor (QP) and is activated by the activation signal, in a manner suitable for bringing the insulated vertical PNP transistor (QP) practically to BVCBO.
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公开(公告)号：DE69018362T2
公开(公告)日：1995-11-23
申请号：DE69018362
申请日：1990-10-04
Applicant: SGS THOMSON MICROELECTRONICS
Inventor： GARIBOLDI ROBERTO , GOLA ALBERTO
IPC: H02H9/04 , H02H7/20 , H03K19/003 , H02H11/00
Abstract: A negative overvoltage protection circuit for stages having a transistor with collector output and with the emitter connected to a reference voltage line; a diode (D1) for protection against negative overvoltages present on the output (Vout) is arranged between the collector and the output of the stage. In order to give the output of the stage a presettable minimum voltage level, the reference voltage line is set to a preset voltage which differs from the ground voltage. For this purpose, the circuit comprises an operational amplifier (Op) in a voltage-follower configuration, the output whereof is connected to the reference voltage line, a diode (D2) which is connected between the ground and the non-inverting terminal of the operational amplifier (Op), and a current source which is connected between the non-inverting input of the operational amplifier (Op) and a negative supply line (-VEE).
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