Patent ID: 6580277
Filing Date: 2003-06-17
Classification: B60R,G01D,G06F

Abstract:
A device for ratiometric measurement of sensor signals, comprising:a supply input for receiving a supply voltage; an analog/digital converter connected to said supply input to receive the supply voltage, said analog/digital converter connected to receive a first reference voltage; a sensor for providing an analog output signal that is supplied to said analog/digital converter, said sensor connected to receive a second reference voltage; a voltage controller supplying the supply voltage to said supply input, and supplying, independently from the supply voltage, the second reference voltage; a first resistor connected to receive the second reference voltage; a voltage divider including a second resistor, a third resistor, and a voltage tap between said second resistor and said third resistor; a fourth resistor connected to said voltage tap of said voltage divider; and an operational amplifier that is connected as a voltage follower for forming the first reference voltage; said operational amplifier having a noninverting input connected to said first resistor to receive the second reference voltage, said operational amplifier having an output connected through said voltage divider to said supply input; said operational amplifier having an inverting input connected through said fourth resistor to said voltage tap of said voltage divider; and said voltage tap of said voltage divider providing the first reference voltage.