Resistor Geometry Comparison With Respect to Current Noise and TrimSensitivity

[摘要] The paper deals with laser trimming of film resistors. The finite-difference solution of the electric field calculated bya digital computer gives the total resistance and the inhomogeneous current distribution within the resistor area. Thecurrent noise voltage was found to be proportional to the sum of reciprocal subareas wherein the current density isapproximately constant. Resistor trimming is modelled by finite increments of cut length to obtain the resistancetrim rate and the trim sensitivity.Known and new resistor geometries and cut configurations are compared (based on the same resistor area andthe same initial tolerance of ± 20%) to find the optimal geometry depending on the ratio of the nominal resistancevalue to the sheet resistivity. Diagrams are given leading to practical design rules not only for resistance trimming butalso for deterministic and functional tuning.

[学科分类] 工程和技术（综合）