ONBOARD SCREENING APPARATUS

摘要

PROBLEM TO BE SOLVED: To surely screen a semiconductor integrated circuit onboard by switching a power source voltage supplied to the semiconductor integrated circuit to a higher voltage than a normal voltage by a voltage regulator in accordance with a switch signal from a control circuit at the time of screening. SOLUTION: A normal power source voltage is impressed to an onboard semiconductor integrated circuit including a CPU 4, thereby to check the operation of an ECU(electronic control unit) 1. After the ECU is confirmed to operate normally, a circumferential temperature is raised and a high voltage switch command is transferred from an external communication circuit 15 to the CPU 4. The CPU 4 changes a switch signal TEST from a low level to a high level, switches the resistance ratio of a detection resistor of a voltage regulator 2 thereby to switch the power source voltage to a higher burn-in voltage than the normal voltage, then starts screening. Upon completion, the CPU 4 returns the power source voltage to the normal voltage and confirms by a power source voltage monitor of a voltage monitor circuit 3 when the source voltage is returned to the normal voltage.