Patent ID: 11940402
Assignee: SCIOSENSE B.V.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 15:
16. A circuit arrangement comprising:
a first branch comprising:
a terminal for a supply potential;
a resistor of variable resistance;
a bipolar transistor connected as a diode; and
a terminal for ground potential connected to the bipolar transistor;

a second branch comprising:
a resistor of fixed resistance, the resistor of fixed resistance connected to the resistor of the first branch; and
another bipolar transistor connected as a diode, the terminal for ground potential connected to the other bipolar transistor;

a control loop configured to reproduce a voltage drop at the resistor of variable resistance to a voltage drop at the resistor of fixed resistance;
an output terminal connected to the bipolar transistor of the first branch and another output terminal connected to the other bipolar transistor of the second branch, the output terminals configured to supply a differential voltage;
an analog-to-digital converter connected downstream of the output terminal and the other output terminal, the analog-to-digital converter configured to generate a digital representation of the differential voltage; and
a calculator configured to generate a digital value representative of the resistance of the resistor of variable resistance,
wherein the calculator performs a calculation according to the formula:, R
    
     S
     ⁢
     E
     ⁢
     N
     ⁢
     S
     ⁢
     O
     ⁢
     R
    
   
   =
   
    
     R
     
      R
      ⁢
      E
      ⁢
      F
     
    
    ·
    
     exp
     ⁡
     (
     
      
       Δ
       ⁢
       
        V
        
         B
         ⁢
         E
        
       
      
      
       
        
         K
         ⁢
         T
        
        q
       
       ⁢
       η
      
     
     )
    
   
  
  ,, and
wherein RSENSOR represents a resistance value of the resistor of variable resistance, RREF represents a resistance value of the resistor of fixed resistance, ΔVBE represents the differential voltage, K represents a Boltzmann constant, T represents a temperature, q represents an electron charge and η represents an ideality factor at least one of the bipolar transistors.