Timing generation circuit for electro-optic sampling oscilloscope

An electro-optic sampling oscilloscope which carries out measurement of a measured signal using an optical pulse generated based on a timing signal from a timing generation circuit, wherein said timing generation circuit comprises;

• a frequency measurement circuit which generates a gate signal having a predetermined pulse width according to a desired sampling rate, and counts trigger pulses of a trigger signal during a pulse of said gate signal;
• a monitoring circuit which includes a divider ratio determination means having a ratio table including at least one of a preset upper limit value and a preset lower limit value of trigger pulse count corresponding to each divider ratio, the ratio determination means determines a divider ratio based the ratio table and on the count value of the trigger pulses of the trigger signal from said frequency measurement circuit;
• and
• a first divider which divides said trigger signal by a divider ratio determined by said divider ratio determination means, and outputs the result as a timing signal.