公开(公告)号：DE69226021D1

公开(公告)日：1998-07-30

申请号：DE69226021

申请日：1992-09-23

Applicant: ST MICROELECTRONICS SRL

Inventor： TOMASINI LUCIANO ,  CASTELLO RINALDO ,  CONFALONIERI PIERANGELO

IPC: H03K17/06 ,  H03K17/687

Abstract: A driver circuit for an electronic switch (2) which is to be operated from a clock signal (F) having a predetermined frequency, comprises an input pin (A) being applied the clock signal, and a voltage doubler (1) connected between said pin (A) and the switch (2).

公开(公告)号：IT1252533B

公开(公告)日：1995-06-19

申请号：ITMI913376

申请日：1991-12-17

Applicant: ST MICROELECTRONICS SRL

Inventor： TOMASINI LUCIANO ,  CASTELLO RINALDO

IPC: H04M20060101 ,  H04M1/00 ,  H04M1/60 ,  H04M1/76 ,  H04M19/08 ,  H04M

Abstract: A circuit is described which comprises an operational amplifier A, two resistors R1, R2, connected between the telephone line L and the inputs of the amplifier, a capacitor C, which is charged by a first bipolar transistor P1 controlled by the amplifier via a first FET transistor M1, a second bipolar transistor P2 arranged in parallel with the connection of the first transistor P1 and the capacitor C, a second FET transistor M2, equal to the first and with "source" and "gate" terminals connected to the corresponding terminals of the first one, and two current generators CC1, CC2, connected to the "drain" terminals, respectively, of the first and the second FET transistor and to the bases, respectively, of the first and the second bipolar transistor P1, P2. The currents I1, I2 of the two generators and the other parameters of the circuit are such as to keep the first and the second bipolar transistor respectively conducting and inhibited, except in the case when the line voltage drops below a minimum predetermined value: in such case, the first and the second transistor respectively switch to inhibition and conduction. The circuit has a lower "voltage loss" than the known circuits.