In this brief, a multiplying delay-locked loop (MDLL) using a frequency calibrator (FC) and a voltage monitor (VM) is presented. This FC uses a delay-calibrated subsampling phase detector (SSPD) to reduce the frequency error. The VM is used to cover a wide frequency variation. This MDLL is fabricated in 40-nm CMOS technology. Its active area is 0.013 mm2, and the power consumption is 5.2 mW from a supply of 1 V. It exhibits a root-mean-square jitter of 229 fs at 2.4-GHz output and the reference spur of −54.3 dBc under a reference clock of 150 MHz.