A 78 fs RMS Jitter Injection-Locked Clock Multiplier Using Transformer-Based Ultra-Low-Power VCO

This paper presents a low jitter performance and low power consumption injection-locked clock multiplier (ILCM) for IoT application in 65-nm CMOS. A transformer-based ultra-low power (ULP) LC-VCO is proposed to minimize the overall power consumption. The introduced capacitor feedback path boosts the VCO loop gain and thus a robust startup can be obtained. The proposed transformer-based VCO achieves −115.1 dBc/Hz at 1 MHz frequency offset with a 97 μW power consumption, which corresponds to a -194 dBc/Hz VCO figure-of-merit (FoM). Thanks to the proposed low power VCO, the total ILCM achieves 78 fs RMS jitter while consuming 210 μW power. A -269 dB FoMJP of jitter and power is achieved by this proposed ILCM, and a -262 dB FoMJRP is obtained while considering the 520 MHz input reference with multiplication factor equals to 5.