Direct-to-digital temperature sensor

Abstract

A direct-to-digital temperature sensor is formed with a single switched-capacitor integrator, having a digital sequencer control.

What is claimed is:  
     
         1 . A temperature sensor comprising: 
 a switched-capacitor integrator; and    a digital sequencer control.    
     
     
         2 . The temperature sensor of    claim 1   , further comprising means for canceling integrator offset voltage.  
     
     
         3 . The temperature sensor of    claim 2   , wherein said means for canceling comprises a separate capacitor used to sample integrator offset.  
     
     
         4 . The temperature sensor of    claim 3   , wherein said separate capacitor allows implementation of correlated—doubled sampling.  
     
     
         5 . The temperature sensor of    claim 2   , wherein said means for canceling comprises means for reversing integrator offset halfway through conversions.  
     
     
         6 . The temperature sensor of    claim 1   , further comprising means for eliminating mismatch between two different biasing currents.  
     
     
         7 . The temperature sensor of    claim 6   , wherein said means for eliminating comprises means for swapping sampling and integration phases in Vbe 1  and Vbe 2  generation circuits.  
     
     
         8 . The temperature sensor of    claim 6   , wherein said biasing currents are used to bias two bipolar transistors with different effective areas.  
     
     
         9 . The temperature sensor of    claim 6   , wherein said biasing currents are used to bias diodes with different effective areas.  
     
     
         10 . The temperature sensor of    claim 1   , wherein there are only three inputs to the system.  
     
     
         11 . A system employing thermal management components comprising: 
 a switched-capacitor integrator; and    a digital sequencer control for said switched capacitor integrator.    
     
     
         12 . The system of    claim 11   , further comprising means for canceling offset errors in said thermal management components.  
     
     
         13 . The system of    claim 11   , further comprising means for eliminating current mismatches in said thermal management components.  
     
     
         14 . A method of detecting temperature comprising the steps of: 
 sampling voltages using a switched-capacitor integration; and    controlling sampling with a digital sequencer.    
     
     
         15 . The method of    claim 14   , further comprising the steps of canceling integrator offset error.  
     
     
         16 . The method of    claim 14   , further comprising the step of eliminating biasing current mismatches.