Differential filter circuit and integrated circuit structure therefor

An integrated circuit structure comprising:

• a first insulating layer;
• a first electrode formed to be in contact with a first surface of said first insulating layer;
• a second electrode and a third electrode formed on an opposite second surface of said first insulating layer at positions opposite to said first electrode;
• a fourth electrode and a fifth electrode formed at positions opposite to said second electrode and said third electrode, respectively, through a second insulating layer;
• a first resistor and a second resistor formed on the second surface of said first insulating layer;
• a first conductor for connecting said first electrode to a reference potential;
• a second conductor for connecting a first end of said first resistor to said second electrode;
• a third conductor for connecting a first end of said second resistor to said third electrode;
• a fourth conductor for connecting said second electrode to said fifth electrode;
• a fifth conductor for connecting said third electrode to said fourth electrode;
• a first input terminal connected to a second end of said first resistor and a second input terminal connected to a second end of said second resistor, respectively;
• and
• first and second output terminals connected to said fourth electrode and said fifth electrode, respectively,
• wherein said first electrode and said second electrode form a first capacitor, said first electrode and said third electrode form a second capacitor, said second electrode and said fourth electrode form one capacitor constituting a third capacitor, and said third electrode and said fifth electrode form another capacitor constituting said third capacitor, said first and second resistors and said first, second and third capacitors constituting a first-order differential low pass filter.

A second-order differential low pass filter comprising:

• a first resistor connected between a first input terminal and a first junction point, and a second resistor and connected between the first junction point and a first output terminal;
• a third resistor having the same resistance value as said first resistor and connected between a second input terminal and a second junction point, and a fourth resistor having the same resistance value as said third resistor and connected between the second junction point and a second output terminal;
• a first capacitor connected between the first junction point and a reference potential;
• a second capacitor connected between the first junction point and the second junction point;
• a third capacitor connected between said first output terminal and said second output terminal;
• and
• a fourth capacitor connected between said second output terminal and said reference potential, said fourth capacitor having the same capacitance value as said first capacitor.

An integrated circuit structure comprising:

• a first insulating layer;
• a first electrode formed to be in contact with a first surface of said first insulating layer;
• a second electrode and a third electrode formed on opposite second surface of said first insulating layer at positions opposite to said first electrode;
• a fourth electrode and a fifth electrode formed at positions opposite to said second electrode and said third electrode, respectively, on a second insulating layer covering said second and third electrodes;
• a first resistor, a second resistor, a third resistor and a fourth resistor formed on the first surface;
• a first conductor for connecting said first electrode to a reference potential;
• a second conductor for connecting a first end of said first resistor to a first end of said third resistor and to said second electrode;
• a third conductor for connecting a first end of said second resistor to a first end of said fourth resistor and to said fourth electrode;
• a fourth conductor for connecting a second end of said third resistor to said fifth electrode;
• a fifth conductor for connecting a second end of said fourth resistor to said third electrode;
• a first input terminal connected to a second end of said first resistor and a second input level connected to a second end of said second resistor;
• and
• a first output terminal connected to said third electrode and to said fifth electrode, respectively;
• wherein said first electrode and said second electrode form a first capacitor, said second electrode and said fourth electrode form a second capacitor, said third electrode and said fifth electrode form a third capacitor and said first electrode and said third electrode form a fourth capacitor, said first, second, third, and fourth resistors and said first, second, third, and fourth capacitors constituting a second-order differential low pass filter.

An integrated circuit structure comprising:

• a first insulating layer;
• a first electrode formed to be in contact with a first surface of said first insulating layer;
• a second electrode and a third electrode formed on an opposite second surface of said first insulating layer at positions opposite to said first electrode;
• a fourth electrode and a fifth electrode formed at positions opposite to said second electrode and said third electrode, respectively, on a second insulating layer;
• a first resistor, a second resistor, a third resistor and a fourth resistor formed on the second surface of said first insulating layer;
• a first conductor for connecting said first electrode to a reference potential;
• a second conductor for connecting a first end of said first resistor to a first end of said third resistor and to said fourth electrode;
• a third conductor for connecting a first end of said second resistor to a first end of said fourth resistor and to said second electrode;
• a fourth conductor for connecting a second end of said third resistor to said third electrode;
• a fifth conductor for connecting the other end of said fourth resistor to said fifth electrode;
• a first input terminal connected to a second end of said first resistor and a second input terminal connected to a second end of said second resistor, respectively, and
• first and second output terminals connected to said third electrode and said fifth electrode, respectively;
• wherein said first electrode and said second electrode form a first capacitor, said second electrode and said fourth electrode form a second capacitor, said third electrode and said fifth electrode form a third capacitor and said first electrode and said third electrode form a fourth capacitor, said first, second, third, and fourth resistors and said first, second, third, and fourth capacitors constituting a second-order differential low pass filter.

A differential high pass filter comprising:

• a first capacitor connected between a first input terminal and a first output terminal;
• a second capacitor having the same capacitance value as said first capacitor and connected between a second input terminal and a second output terminal;
• a first resistor connected between said first output terminal and a reference potential;
• a second resistor having the same resistance value as said first resistor and connected between said second output terminal and said reference potential;
• and
• a third resistor connected between said first output terminal and said second output terminal.