| 摘要 |
PURPOSE:To measure the degree of logical floating by a method wherein data of a signal to be measured is collected whenever a threshold voltage is altered, and the data is compared with the measuring signal against the normal foregoing voltage, while the foregoing voltage at a point of time when the output of a comparator appears is displayed. CONSTITUTION:An up-down counter 10 is loaded with the standard value of a standard threshold register 9, and voltage is proportion to the value is supplied to a voltage comparing circuit 1, then an address switching circuit 4 is switched on the address counter side, while the value is memorized in a memory circuit 2, before being transferred to a memory circuit 3. The up-down counter 10 is up-counted in order to let an input data be memorized in the memory circuit 2, and the address circuit 4 is switched on the comparing side, before being operated. On repeating the above operations, an output is produced in a comparator 7, but a threshold level at a point of time when the first output in each channel corresponds to the I threshold, and this is memorized in a memory circuit 8, then displayed by a display circuit 12. Next, the same procedure is applied to the count-down side of the counter 10 so that the voltage equivalent to the 10 threshold is measured. |
