Current sensing device for micro-IDDQ test

In LSIs with more than 1 million gates, detection of the defective location s becomes difficult. In particular, in the case of an abnormality in the st andby current, excessive power is consumed even if operation is successful. Hence, it is necessary to identify the error location in order to reduce p ower consumption. The IDDQ test detects the error by measuring the static c urrent in standby for each circuit block. A typical implementation is the B ICS (Built-In Current Sensor). However, the conventional method has the pro blems of reduction of the noise margin and degradation of the circuit speed . In this paper, two types of current sensors, the Lorentz force MOSFET (LM OS) and Hall effect MOSFET (HEMOS), based on a magnetic sensor circuit usin g CMOS technology, are proposed. These sensors are capable of non-contactin g and non-disturbing current measurement. A circuit for applications to the IDDQ test is described. (C) 2001 Scripta Technica.