Comment on "Modeling of small-signal minority-carrier transport in bipolar devices at arbitrary injection levels"

For original paper see N. Rinaldi, ibid., vol.45, p.1501-10 (1998). In the original paper, the most accurate existing closed-form analytical solutions to the ac minority carrier continuity equation in quasi-neutral regions of bipolar transistors were assessed by way of open-form infinite series solutions. Contrary to the conclusions drawn, the present author argues that, because the closed-form solutions cannot be derived from the open-form solutions, they cannot be viewed as less accurate approximations to the truncated open-form infinite series solutions.