US 12,444,930 B2
Protection circuit and vehicle-mounted device with the same
Qinggeng Meng, Dalian (CN)
Assigned to Alps Alpine Co., LTD., Tokyo (JP)
Filed by Alps Alpine Co., LTD., Tokyo (JP)
Filed on Apr. 28, 2023, as Appl. No. 18/140,924.
Claims priority of application No. 202210498360.3 (CN), filed on May 9, 2022.
Prior Publication US 2023/0361558 A1, Nov. 9, 2023
Int. Cl. H02H 9/02 (2006.01)
CPC H02H 9/02 (2013.01) 8 Claims
OG exemplary drawing
 
1. A protection circuit comprising:
a first substrate comprising a first circuit connected to a power line and a potential reference line;
a second substrate comprising a second circuit connected to the power line and the potential reference line;
a connecting part comprising:
a potential reference connecting line configured to provide a connection between the potential reference line of the first substrate and the potential reference line of the second substrate, and
a communication connecting line configured to provide a connection between a communication line of the first circuit and a communication line of the second circuit;
a current limiting unit disposed between a first node on the potential reference line of the first substrate at the connecting part side and a second node on the potential reference line of the first substrate at the first circuit side; and
a communication line protection unit configured to limit voltages applied to the communication line of the first circuit and the communication line of the second circuit when current limiting is conducted by the current limiting unit, the communication line protection unit comprising:
a first switching unit and a second switching unit, where one end of each of the first switching unit and the second switching unit is connected to the potential reference connecting line and another end of each of the first switching unit and the second switching unit is connected to the communication connecting line; and
a resistor connected to the communication connecting line between the other end of the first switching unit and the other end of the second switching unit,
wherein the one end of the first switching unit and the one end of the second switching unit are each connected to a respective end of the current limiting unit.