Input sub-ranging converter system for sampling semiconductor temperature sensors

An apparatus for sampling response voltages from a temperature sensor that includes a PN junction, comprising:

• a means for generating an offset voltage in response to a digital code;
• a means for applying a first bias current that is arranged to apply a first bias current to the PN junction such that the PN junction produces a first PN junction voltage, and the temperature sensor produces a first response voltage;
• a means for combining the offset voltage that is arranged to combine the first response voltage with the offset voltage to produce a first signal;
• a means for applying a second bias current that is arranged to apply a second bias current to the PN junction such that the PN junction produces a second PN junction voltage, and the temperature sensor produces a second response voltage, wherein the first bias current is different from the second bias current;
• and
• a means for converting that is arranged to convert the first and second signals to digital codes, wherein the means for converting has an input voltage range that is less than a range of response voltages associated with the temperature sensor.

An apparatus for sampling response voltages from a temperature sensor that includes a PN junction, comprising:

• a programmable current source that is configured to provide one of a first and second currents when selected to the temperature sensor such that the response voltage from the temperature sensor corresponds to a first voltage when the first current is selected and the response voltage corresponds to a second voltage when the second current is selected;
• a controller that is configured to select the first and second currents;
• an intermediate voltage selector that is configured to provide an offset voltage during a measurement mode;
• a summer that is configured to receive the response voltage and the offset voltage, and provide an offset response voltage by subtracting the offset voltage from the response voltage;
• and
• an analog-to-digital converter that is configured to convert the offset response voltage into a digital code during a measurement mode, wherein the analog-to-digital converter has an input voltage range that is less than a range of response voltages associated with the temperature sensor.