Overcoming Impedance-Mismatch Induced Offsets in Background Bond Wire Defect Detection

A background bond wire defect detection method for high accuracy differential DC-current read-out applications is presented. It is demonstrated how it overcomes the SoA limitations and allows to concurrently detect bond wire defects, such as bond opens, shorts to ground/V
supply
and shorts between the connections, without interfering with the main functionality of a sensor readout circuit. A comparison of existing solutions is carried out concerning error coverage as well as the disturbance of the functional measurement signal. Functionalities and limitations are separately discussed and the need for the proposed method is derived from self-induced offset problems. Finally, a closed loop solution is presented that avoids the creation of offsets by impedance mismatches. Matlab Simulink is then used to simulate the techniques in an exemplary system and to compare the results.