A 60 to 200MHz SSCG with approximate Hershey-Kiss modulation profile in 0.11µm CMOS

This paper describes a spread spectrum clock generator (SSCG) circuit generating an approximate Hershey- Kiss modulation profile by dual modulators. The dual modulators consist of a slope modulator and a division modulator. The proposed scheme generates various modulation slopes to achieve a non-linear modulation profile. Since the modulators are implemented by the simple digital blocks, it can be modified upon different applications. The proposed SSCG covers output frequency of 60MHz to 200MHz with a 30KHz modulation frequency designed with a 0.11μm CMOS technology. The spread ratios and modulation positions (down, up, center) also can be controlled.