公开(公告)号：US10291020B2

公开(公告)日：2019-05-14

申请号：US15350736

申请日：2016-11-14

Applicant: ALPINE ELECTRONICS, INC.

Inventor： Norihiko Tanaka

IPC: H02H1/00 ,  H02H9/04 ,  H01L27/06 ,  H01L29/866 ,  H03K19/003

Abstract: An overvoltage protection device includes a resistor that is connected in series between an internal signal line connected to a communication terminal of a processor and a communication line, a diode of which a cathode is connected to the internal signal line and an anode is connected to a ground, and a PNP transistor of which a base is connected to a power supply terminal, an emitter is connected to the internal signal line, and a collector is connected to the ground. When a base-emitter voltage (a junction saturation voltage) of the transistor in operation is defined as VBE and a power source is turned on (a voltage V1) by the operation of the transistor, a voltage of the internal signal line is limited to the source voltage V1+VBE. When the power source is turned off (a voltage 0 V), the voltage of the internal signal line is limited to the source voltage 0 V+VBE.

公开(公告)号：US20170187182A1

公开(公告)日：2017-06-29

申请号：US15350736

申请日：2016-11-14

Applicant: ALPINE ELECTRONICS, INC.

Inventor： Norihiko Tanaka

IPC: H02H9/04 ,  H01L27/06 ,  H02H1/00

CPC classification number: H02H9/044 ,  H01L27/0647 ,  H01L29/866 ,  H02H1/0007 ,  H02H1/0061 ,  H03K19/00315

Abstract: An overvoltage protection device includes a resistor that is connected in series between an internal signal line connected to a communication terminal of a processor and a communication line, a diode of which a cathode is connected to the internal signal line and an anode is connected to a ground, and a PNP transistor of which a base is connected to a power supply terminal, an emitter is connected to the internal signal line, and a collector is connected to the ground. When a base-emitter voltage (a junction saturation voltage) of the transistor in operation is defined as VBE and a power source is turned on (a voltage V1) by the operation of the transistor, a voltage of the internal signal line is limited to the source voltage V1+VBE. When the power source is turned off (a voltage 0 V), the voltage of the internal signal line is limited to the source voltage 0 V+VBE.