| 摘要 |
PROBLEM TO BE SOLVED: To detect faulty parts and characteristics with no test probe even in the cases of occurrence of packaging failures and characteristics failures by accurately measuring the high-frequency characteristics of analog components which requires the measurement of high-frequency characteristics from the view poing of printed circuit's characteristics in a test of printed circuits by analog boundary scanning. SOLUTION: In addition to internal analog test buses 18 and 19 connected to external analog test buses 5 and 6 via semiconductor switches 8 and 9, analog test buses 38 and 39 for measuring high-frequency characteristics in a system different from the above-mentioned buses are directly derived in a minimum wiring length from the external analog test buses 5 and 6 to a specific signal terminal 31 which requires the measurement of high-frequency characteristics and connected to the specific signal terminal 31 via semiconductor switches 40 and 41 of small ON resistance. Therefore, at the time of measuring high-frequency characteristics, it is possible to isolate the internal analog test buses 18 and 19 with large parasitic capacitance loads from a measurement system. |
