×

Semiconductor device having a plurality of circuits driven by different power sources and formed on the same substrate

  • US 5,796,147 A
  • Filed: 08/09/1994
  • Issued: 08/18/1998
  • Est. Priority Date: 08/09/1993
  • Status: Expired due to Fees
First Claim
Patent Images

1. A semiconductor device comprising:

  • a semiconductor substrate having at least a first well and a second well which are electrically divided from each other;

    a first electric circuit formed in said first well and connected to a first circuit power source through a source terminal;

    a second electric circuit formed in said second well and connected to a second circuit power source through a source terminal;

    a substrate ground well formed on said semiconductor substrate and connected to a third circuit power source which outputs a stable reference potential;

    a first protection diode connected between said source terminal of said first power source and said substrate ground well in the manner of being a reverse bias direction; and

    a second protection diode connected between said source terminal of said second power source and said substrate ground well in the manner of being a reverse direction;

    whereby interference between said first and second power sources is prevented by said first and second protection diodes;

    wherein said first protection diode and/or said second protection diode comprises or respectively comprise any or combination of a diode, bipolar transistors which are connected with each other in a diode connection, and metal oxide layer semiconductor (MOS) transistors which are connected with each other in a diode connection.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×