The invention belongs to the technical field of
clock signal synchronization, and particularly relates to an adjustable
delay circuit, which comprises a current starvation driving module used for outputting a driving
signal with preset current magnitude according to an input
signal of the adjustable
delay circuit; the current enhancement driving module is used for enhancing the current of the driving signal; the RC adjusting module is used for adjusting an
RC time constant of the adjustable
delay circuit, so that the driving signal is output after being delayed for preset time; the RC adjusting module comprises an adjustable
resistor; the adjustable
capacitor comprises at least one long delay
capacitor and a plurality of MOS (
Metal Oxide Semiconductor) capacitors, and the long delay
capacitor and each
MOS capacitor are respectively provided with a corresponding
transmission gate, so that the long delay capacitor and each
MOS capacitor are connected to the adjustable delay circuit or disconnected from the adjustable delay circuit; and the
capacitance value of the long delay capacitor is at least greater than the
capacitance value of any
MOS capacitor. According to the adjustable delay circuit provided by the invention, the high-precision and wide-range delay adjustment requirements can be met by adjusting the resistance, the
capacitance and the driving capability.