This paper proposes an innovative method of converting digital signal to time-domain analog signal, which fully enjoys robustness and digital circuit friendliness. This technique utilizes a digital delta-sigma ( ) modulator following a digital-to-time converter (DTC) circuit with various modulation methods. As an application of the proposed method, novel spreadspectrum clock generation (SSCG) algorithms (such as for DC-DC converters) have been investigated which can select the noise spectrum spread bands; e.g., they can exclude the noisespectrum spread in AM, FM radio bands. The proposed circuit takes advantage of digital technology, which is simple, fast (reachable at high clock frequency) and flexible (programmable).