TY - JOUR
AU1 - Motozawa, Atsushi
AU2 - Hiraku, Yasuyuki
AU3 - Hirai, Yoshitaka
AU4 - Hiyama, Naoaki
AU5 - Imanaka, Yusuke
AU6 - Morishita, Fukashi
AB - In the automotive industry, system-on-chips are crucial for managing weak radio waves from space, known as satellite signals. Integer-N phase-locked loops have played a vital role in the operation of system-on-chips in recent history. Their clock frequencies are carefully designed to prevent electromagnetic interference. However, as global navigation satellite system becomes more prevalent, integer-N phase-locked loops face new challenges in generating clocks within the shrinking frequency bands due to large frequency steps determined using a reference clock. To address it, replacing integer-N phase-locked loops with fractional-N phase-locked loops is required. This topic has not been discussed extensively, but it is a practical issue that requires consideration due to its potential impact on development costs. This is why we developed an attachable fractional divider. Our developed divider can efficiently transform integer-N phase-locked loops into fractional-N phase-locked loops, achieving low jitter degradation of 0.35 psrms and a low fractional spur of −69.3 dBc. Thanks to its attachable design, it expedites time-to-market. Regarding mass production, ensuring immunity to process, voltage, and temperature variations is a significant concern. We introduce the circuit techniques employed in the developed fractional divider for immunity to process, voltage, and temperature variations. Subsequently, we provide a comprehensive set of measurement results. The frequency differences over process variations in fractional-N mode is 6.14 ppm. Power supply and temperature dependances are extremely small in spread-spectrum clocking mode. This article illustrates that the developed fractional divider enhances both time-to-market and product reliance.
TI - Circuit Techniques for Immunity to Process, Voltage, and Temperature Variations in the Attachable Fractional Divider
JF - Electronics
DO - 10.3390/electronics12234885
DA - 2023-12-04
UR - https://www.deepdyve.com/lp/multidisciplinary-digital-publishing-institute/circuit-techniques-for-immunity-to-process-voltage-and-temperature-0KVy3yhVpF
SP - 4885
VL - 12
IS - 23
DP - DeepDyve
ER -