Patent ID: 7577044
Filing Date: 2009-08-18
Classification: G01R,G11C

Abstract:
1. A sensing circuit for measuring a resistance of a circuit, comprising: an integrator; a first access device having a first control input connected to an output of the integrator, the first access device being connected to the circuit and to an inverting input of the integrator; a capacitor operatively connected between the first access device and a constant potential; a clocked comparator having a clock input to receive a clock signal; a second access device having a second control input connected to an output of the clocked comparator, the second access device being operably connected between a supply voltage and the first access device; first and second counters, the first counter for counting rising transitions at the output of the clocked comparator during a measuring cycle, the second counter for counting a number of clock transitions of the clock signal during the measuring cycle; a latching buffer having a data input connected to an output of the first counter and a latch input connected to an output of the second counter, and a data output; a digital comparator connected to the data output of the latching buffer to compare the output of the first counter to a reference value to determine the resistance of the circuit.