Circuit and method of providing common mode suppression for amplifier

A semiconductor device, comprising a common mode suppression circuit including a first input terminal and second input terminal coupled for receiving an input signal and further including a first output terminal and a second output terminal providing an output signal with a reduced common mode, wherein the common mode suppression circuit includes,

• (a) a ground plane,
• (b) a first conductive trace disposed over the ground plane and coupled between the first input terminal and first output terminal,
• (c) a second conductive trace disposed over the ground plane and coupled between the second input terminal and second output terminal,
• (d) a third conductive trace disposed over the ground plane with a first end of the third conductive trace coupled to the ground plane and a second end of the third conductive trace open circuit,
• (e) a first insulating layer formed between the ground plane and third conductive trace, and
• (f) a second insulating layer formed between the third conductive trace and the first conductive trace.

A method of making a semiconductor device, comprising:

• providing a substrate;
• forming an amplifier over the substrate;
• forming a common mode suppression circuit over the substrate with a first input terminal and second input terminal coupled for receiving an input signal and a first output terminal coupled to a first input terminal of the amplifier and a second output terminal coupled to a second input terminal of the amplifier to reduce common mode, wherein forming the common mode suppression circuit includes,
• (a) forming a ground plane over the substrate, wherein forming the ground plane includes forming an isolation region to provide slots within the ground plane,
• (b) disposing a first conductive trace over the ground plane and coupled between the first input terminal and first output terminal,
• (c) disposing a second conductive trace over the ground plane and coupled between the second input terminal and second output terminal, and
• (d) disposing a third conductive trace over the ground plane with a first end of the third conductive trace coupled to the ground plane and a second end of the third conductive trace open circuit.

A method of making a semiconductor device, comprising:

• providing a substrate;
• forming an amplifier over the substrate;
• forming a common mode suppression circuit over the substrate with a first input terminal and second input terminal coupled for receiving an input signal and a first output terminal coupled to a first input terminal of the amplifier and a second output terminal coupled to a second input terminal of the amplifier to reduce common mode, wherein forming the common mode suppression circuit includes,
• (a) forming a ground plane over the substrate,
• (b) disposing a first conductive trace over the ground plane and coupled between the first input terminal and first output terminal, wherein the first conductive trace includes a first straight portion and an angled portion extending from the first straight portion and a second straight portion extending from the angled portion,
• (c) disposing a second conductive trace over the ground plane and coupled between the second input terminal and second output terminal, and
• (d) disposing a third conductive trace over the ground plane with a first end of the third conductive trace coupled to the ground plane and a second end of the third conductive trace open circuit.

A semiconductor device, comprising a common mode suppression circuit including a first input terminal and second input terminal coupled for receiving an input signal and further including a first output terminal and a second output terminal providing an output signal with a reduced common mode, wherein the common mode suppression circuit includes,

• (a) a ground plane,
• (b) a first conductive trace disposed over the ground plane and coupled between the first input terminal and first output terminal, wherein the first conductive trace includes a first straight portion and an angled portion extending from the first straight portion and a second straight portion extending from the angled portion,
• (c) a second conductive trace disposed over the ground plane and coupled between the second input terminal and second output terminal, and
• (d) a third conductive trace disposed over the ground plane with a first end of the third conductive trace coupled to the ground plane and a second end of the third conductive trace open circuit.