  Superconducting quantum computers (SQC) can solve some specific problems
which are deeply believed to be intractable for classical computers. The
control and measurement of qubits can't go on without the synchronous operation
of digital-to-analog converters (DAC) array and the controlled sampling of
analog-to-digital converters (ADC). In this paper, a scalable self-adaptive
synchronous triggering system is proposed to ensure the synchronized operation
of multiple qubits. The skew of the control signal between different qubits is
less than 25 ps. After upgrading the clock design, the 250 MHz single-tone
phase noise of DAC has been increased about 15 dB. The phase noise of the 6.25
GHz qubit control signal has an improvement of about 6 dB.
