| 摘要 |
<p>PURPOSE:To accelerate trimming by stopping the trimming when comparing and discriminating means detects the coincidence of the state of a signal to be trimmed with that designated by a reference signal during the trimming. CONSTITUTION:A resistor or the like of an element 1 to be trimmed is radiated with a laser beam L while comparing a voltage to be trimmed corresponding to a frequency generated from the element 1 to be trimmed with a reference voltage Vx by a voltage conversion comparator 9, thereby performing rough regulation trimming. The voltage to be trimmed gradually approaches the voltage Vx as the radiation of the beam L, and when both becomes equal, a comparison signal Vf applied from the comparator 9 to a CPU 11 arrives at a predetermined threshold value level, and the CPU 11 stops radiating of the beam L. Thus, since the CPU 11 is interrupted by the comparison signal Vf output when the voltage to be trimmed coincides with the voltage Vx, it can be trimmed while radiating the element 1 to be trimmed with the beam L, thereby shortening the time required for the trimming.</p> |
