Temperature Sensor Peripheral Having Independent Temperature Coefficient And Offset Adjustment Programmability

Abstract

A temperature sensor peripheral generates an output voltage that is proportional to temperature, whose temperature coefficient can be adjusted to any desired value, whose temperature coefficient can be either positive or negative, whose room temperature voltage can be adjusted to any desired value, and whose temperature coefficient and room temperature voltage adjustments are independent from one another.

1 - 13 . (canceled) 
     
     
         14 . A mixed signal integrated circuit adapted for coupling to a temperature sensor and providing voltages proportional to temperatures measured by the temperature sensor, comprising:
 a digital processor and memory;   a temperature sensor peripheral comprising   a first operational amplifier having first and second inputs and an output,   a third resistor coupled between the output and the second input of the first operational amplifier,   a second operational amplifier having first and second inputs and an output,   first and second transistors having sources coupled together, gates coupled to an output of the second operational amplifier, and drains coupled to first and second resistors;   wherein a temperature sensor is coupled to the first input of the second operational amplifier, and a reference voltage is coupled to the first input of the first operational amplifier;   wherein the output of the first operational amplifier provides an output voltage proportional to a temperature measured by the temperature sensor.   
     
     
         15 . The mixed signal integrated circuit according to  claim 14 , wherein the first, second and third resistors are programmable and controlled by the digital processor. 
     
     
         16 . The mixed signal integrated circuit according to  claim 14 , further comprising a digital-to-analog converter coupled to the digital processor and providing a programmable reference voltage. 
     
     
         17 . The mixed signal integrated circuit according to  claim 14 , further comprising an analog-to-digital converter having an input coupled to the output of the first operational amplifier and an output coupled to the digital processor. 
     
     
         18 . The mixed signal integrated circuit according to  claim 14 , wherein the mixed signal integrated circuit comprises a microcontroller. 
     
     
         19 . A circuit arrangement for measuring a temperature, comprising:
 two current generation circuits providing first and second currents in two different paths, wherein one of the first or second currents is dependent upon temperature;   the first and second currents are combined and converted into a voltage Vtemp, wherein the voltage Vtemp is dependent upon the temperature.   
     
     
         20 . The circuit arrangement according to  claim 19 , wherein the voltage Vtemp is equal to a reference voltage when the first and second currents are equal. 
     
     
         21 . The circuit arrangement according to  claim 19 , wherein the combined first and second currents are converted into the voltage Vtemp by an amplifier having a feedback resistor. 
     
     
         22 . The circuit arrangement according to  claim 21 , wherein the feedback resistor determines a variation of the voltage Vtemp over a variation of the temperature. 
     
     
         23 . The circuit arrangement according to  claim 19 , wherein the two current generation currents are voltage-to-current converters, and the temperature is measured by a temperature sensor having a voltage output coupled to one of the two voltage-to-current converters. 
     
     
         24 . A method for measuring temperatures and producing voltages representative thereof, said method comprising the steps of:
 determining a first voltage representing a first calibration temperature;   adjusting a first output voltage from a temperature sensor peripheral to equal the first voltage when a temperature sensor is at the first calibration temperature;   determining a range of voltages to represent a range of temperatures, wherein the first voltage is within the range of voltages and the first calibration temperature is within the range of temperatures;   determining a second voltage representing a second calibration temperature within the range of temperatures; and   adjusting a second output voltage from the temperature sensor peripheral to equal the second voltage when the temperature sensor is at the second calibration temperature.   
     
     
         25 . The method according to  claim 24 , wherein the first voltage is equal to a reference voltage coupled to an input of an operational amplifier of the temperature sensor peripheral. 
     
     
         26 . The method according to  claim 24 , wherein the first calibration temperature is room temperature.