ICT(IN-CIRCUIT TESTER) USING ALIAS SAMPLING AND AC MEASUREMENT METHOD THEREOF

摘要

An ICT(In-Circuit Tester) using alias sampling and an AC measurement method using the same are provided to obtain the same measurement signal although an A/D(Analog To Digital) converter relatively slow is used, by applying alias sampling and to calculate phase exactly by using a phase calculation algorism. An ICT using alias sampling comprises of a switch matrix unit selecting an element(311) on a PCB(300) to be measured; a measuring unit(340) connected with the switch matrix unit to measure DC or AC current or voltage(342,343); a control unit(350) controlling the selection of the switch matrix unit and the driving, measuring, and calculation of the measuring unit; and a memory unit storing the control order of the control unit and the measurement result. The measuring unit applies AC constant voltage or AC constant current(341) to measurement elements(321,322) by a control signal of the control unit and A/D-converts an AC signal of the measured element by alias sampling and time compression(341,344). The control unit calculates the phase and magnitude of the time-compressed AC signal and then computes impedance of the element to be measured(353,354).