2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/216952We develop the vertex detector for the international linear collider (ILC) using the FPCCD (Fine Pixel CCD), whose pixel size is 5 x 5 um2. Together with the FPCCD sensor, a prototype of the readout ASIC was developed in 2008. The readout ASIC was confirmed to work correctly at slow readout speed (1.5 Mpix/sec). In this letter, we describe the status of the performance study for the readout ASIC.4 pages, 5 figures, Proceedings of LCWS08Instrumentation and DetectorsAccelerator Physicstext