A distance meter circuit includes: a driver for generating a driving pulse according to a measuring control signal to drive a laser diode to emit a light pulse to an object; a photonic sensing device for generating a first light conversion signal in response to the light pulse reflected by the object; a read-out circuit for measuring a TOF of the light pulse reflected by the object; an adjustable delay circuit for providing an adjustable delay time between the measuring control signal and the measuring trigger signal, or between the measuring control signal and the driving pulse; and a DLL controller for generating a delay control signal by comparing a phase difference between the measuring trigger signal and a driving related signal related to the driving pulse such that the phase difference is regulated to a predetermined value.