On-chip temperature sensor circuits

Abstract

A diode voltage from a diode circuit can be combined with a proportional to absolute temperature (PTAT) voltage generated by a PTAT circuit to determine a temperature sensor voltage. This temperature sensor voltage may correspond to a temperature of a circuit or a localized temperature. By determining the temperature sensor voltage using a combination of a PTAT voltage and diode voltage, it is possible to remove or a PTAT circuit used to generate a bandgap voltage, which may shrink the temperature sensor and increase the accuracy of the temperature sensor circuit.

1 . A temperature sensor die comprising:
 a temperature sensor including a plurality of circuit elements; and   a plurality of heaters distributed among the plurality of circuit elements and configured to modify a temperature of the temperature sensor when provided with a current.   
     
     
         2 . The temperature sensor die of  claim 1  wherein the plurality of circuit elements include a plurality of diodes and the plurality of heaters include a plurality of resistors. 
     
     
         3 . The temperature sensor die of  claim 2  wherein at least one resistor from the plurality of resistors receives a different current than at least one other resistor from the plurality of resistors. 
     
     
         4 . The temperature sensor die of  claim 2  wherein at least one resistor from the plurality of resistors receives the current and at least one resistor from the plurality of resistors does not receive the current. 
     
     
         5 . The temperature sensor die of  claim 1  wherein the current is received from a controller of a test board configured to test the temperature sensor die and the temperature sensor is configured to provide an output voltage to the controller. 
     
     
         6 . The temperature sensor die of  claim 1  wherein the plurality of circuit elements are distributed in a set of columns on the temperature sensor die. 
     
     
         7 . The temperature sensor die of  claim 6  wherein the plurality of heaters form a second set of columns, the second set of columns interleaved with the set of columns. 
     
     
         8 . A method of testing a temperature sensor, the method comprising:
 determining, by a controller included on a test board configured to test the temperature sensor, a first temperature of a temperature sensor under test;   determining, by the controller, a first output of the temperature sensor under test;   causing, by the controller, a heater integrated with the temperature sensor to heat at least one circuit element of the temperature sensor causing a change in temperature of at least a portion of the temperature sensor under test;   determining, by the controller, a second temperature of the temperature sensor under test;   determining, by the controller, a second output of the temperature sensor under test; and   determining, by the controller, whether a difference between the second output and the first output corresponds to a change between the second temperature and the first temperature.   
     
     
         9 . The method of  claim 8  wherein determining the first temperature of the temperature sensor includes determining a temperature of one or more circuit elements of the temperature sensor. 
     
     
         10 . The method of  claim 8  wherein the first output and the second output are voltages that correspond to a temperature measured by the temperature sensor. 
     
     
         11 . The method of  claim 8  wherein causing the heater to heat the at least one circuit element includes providing a current to the heater, the amount of current provided to the heater corresponding to a particular desired change in temperature determined based at least in part on a test profile supplied to the controller. 
     
     
         12 . The method of  claim 8  wherein determining whether the difference between the second output and the first output corresponds to the change between the second temperature and the first temperature includes determining whether the difference between the second output and the first output matches an expected difference based at least in part on the change between the second temperature and the first temperature. 
     
     
         13 . The method of  claim 8  further comprising performing a corrective action on the temperature sensor when determining that the difference between the second output and the first output does not correspond to a change between the second temperature and the first temperature. 
     
     
         14 . The method of  claim 13  wherein performing the corrective action includes trimming one or more voltages generated by the temperature sensor. 
     
     
         15 . A temperature sensor test system comprising:
 a temperature sensor die including a temperature sensor and a plurality of heaters, the temperature sensor including a plurality of circuit elements, and the plurality of heaters distributed among the plurality of circuit elements and configured to modify a temperature of the temperature sensor when provided with a current; and   a controller configured to provide the current to at least one heater of the plurality of heaters to control the temperature of the temperature sensor, receive an output voltage from the temperature sensor die, and determine based on the output voltage whether a change in the output voltage corresponds to a change in the temperature of the temperature sensor.   
     
     
         16 . The temperature sensor test system of  claim 15  wherein the plurality of circuit elements include a plurality of diodes and the plurality of heaters include a plurality of resistors. 
     
     
         17 . The temperature sensor test system of  claim 16  wherein at least one resistor from the plurality of resistors receives a different current than at least one other resistor from the plurality of resistors. 
     
     
         18 . The temperature sensor test system of  claim 16  wherein at least one resistor from the plurality of resistors receives the current and at least one resistor from the plurality of resistors does not receive the current. 
     
     
         19 . The temperature sensor test system of  claim 15  wherein the plurality of circuit elements are distributed in a first set of columns on the temperature sensor die. 
     
     
         20 . The temperature sensor test system of  claim 19  wherein the plurality of heaters form a second set of columns, the second set of columns interleaved with the first set of columns.