Semiconductor integrated circuit equipped with diagnostic circuit for checking reference voltage signal supplied to internal step-down circuit

摘要

An internal step-down circuit is incorporated in an integrated circuit device for reduction in power consumption as well as for scaling-down, and produces an internal step-down power voltage level regulated to a reference voltage level internally produced by an internal reference signal generator, wherein a diagnostic circuit compares the reference voltage level with an external variable voltage level to see if or not the reference voltage level is higher than the external voltage level, and the external variable voltage level is changed to determine the matching point therebetween, thereby confirming the reference voltage level after packaging.