Patent ID: 7613586

Claim:
A pressure sensor comprising: a substrate; a heating structure situated on the substrate; and a sensing structure proximate to the heating structure and situated on the substrate; and wherein the pressure of an ambient gas is determined by an amount of thermal conduction between the heating structure and the sensing structure; and further comprising: a heating element situated in the heating structure; a temperature sensing element situated in the sensing structure; and a sensing and control electronics circuit connected to the temperature sensing element and the heating element; and wherein the sensing and control electronics circuit comprises: a first resistor having a first end for connection to a source terminal, and having a second end; a second resistor having a first end connected to the second end of the first resistor, and having a second end for connection to a reference terminal; a third resistor having a first end connected to a first end of the temperature sensing element and a second end for connection to the reference terminal; and an amplifier having a first input connected to the second end of the first resistor, and a second input connected to the second end of the sensing element, and having an output.