Abstract
A low-jitter, low-power ring oscillator (RO)-based injection-locked clock multiplier (ILCM) is presented. It employs a background-calibrated reference frequency doubler to increase the RO noise suppression bandwidth, a digital delay-locked loop (DLL) to achieve second-order suppression of RO noise, and a digital frequency-tracking loop (FTL) to continuously tune the oscillator's free-running frequency and ensure a robust operation across process, voltage, and temperature (PVT) variations. A least-mean-square (LMS) algorithm is used to accurately cancel the deterministic jitter (DJ) caused by input duty cycle errors. Fabricated in the 65-nm CMOS process, the prototype ILCM occupies an active area of 0.09 mm2 and generates an output clock in the range of 2.5-5.75 GHz using a 125-MHz reference clock. At 5 GHz, it achieves an integrated jitter of 335 fsrms, while consuming 5.3 mW of power. This translates to the best reported figure-of-merit (FoM) of -242.4 dB for a ring-based ILCM at this high frequency.
| Original language | English (US) |
|---|---|
| Article number | 8691469 |
| Pages (from-to) | 2049-2058 |
| Number of pages | 10 |
| Journal | IEEE Journal of Solid-State Circuits |
| Volume | 54 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1 2019 |
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Keywords
- Delay line
- delay-locked loop (DLL)
- digital phase-locked loop (PLL)
- digitally controlled delay line (DCDL)
- digitally controlled oscillator (DCO)
- flicker noise
- frequency doubler
- injection locking
- injection-locked clock multiplier (ILCM)
- jitter
- least mean square (LMS)
- multiplying injection-locked oscillator (MILO)
- phase noise
- PLL
- reference doubler
- ring oscillator (RO)
ASJC Scopus subject areas
- Electrical and Electronic Engineering
Cite this
A 2.5-5.75-GHz Ring-Based Injection-Locked Clock Multiplier with Background-Calibrated Reference Frequency Doubler. / Elkholy, Ahmed; Coombs, Daniel; Nandwana, Romesh Kumar; Elmallah, Ahmed; Hanumolu, Pavan Kumar.
In: IEEE Journal of Solid-State Circuits, Vol. 54, No. 7, 8691469, 01.07.2019, p. 2049-2058.Research output: Contribution to journal › Article
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TY - JOUR
T1 - A 2.5-5.75-GHz Ring-Based Injection-Locked Clock Multiplier with Background-Calibrated Reference Frequency Doubler
AU - Elkholy, Ahmed
AU - Coombs, Daniel
AU - Nandwana, Romesh Kumar
AU - Elmallah, Ahmed
AU - Hanumolu, Pavan Kumar
PY - 2019/7/1
Y1 - 2019/7/1
N2 - A low-jitter, low-power ring oscillator (RO)-based injection-locked clock multiplier (ILCM) is presented. It employs a background-calibrated reference frequency doubler to increase the RO noise suppression bandwidth, a digital delay-locked loop (DLL) to achieve second-order suppression of RO noise, and a digital frequency-tracking loop (FTL) to continuously tune the oscillator's free-running frequency and ensure a robust operation across process, voltage, and temperature (PVT) variations. A least-mean-square (LMS) algorithm is used to accurately cancel the deterministic jitter (DJ) caused by input duty cycle errors. Fabricated in the 65-nm CMOS process, the prototype ILCM occupies an active area of 0.09 mm2 and generates an output clock in the range of 2.5-5.75 GHz using a 125-MHz reference clock. At 5 GHz, it achieves an integrated jitter of 335 fsrms, while consuming 5.3 mW of power. This translates to the best reported figure-of-merit (FoM) of -242.4 dB for a ring-based ILCM at this high frequency.
AB - A low-jitter, low-power ring oscillator (RO)-based injection-locked clock multiplier (ILCM) is presented. It employs a background-calibrated reference frequency doubler to increase the RO noise suppression bandwidth, a digital delay-locked loop (DLL) to achieve second-order suppression of RO noise, and a digital frequency-tracking loop (FTL) to continuously tune the oscillator's free-running frequency and ensure a robust operation across process, voltage, and temperature (PVT) variations. A least-mean-square (LMS) algorithm is used to accurately cancel the deterministic jitter (DJ) caused by input duty cycle errors. Fabricated in the 65-nm CMOS process, the prototype ILCM occupies an active area of 0.09 mm2 and generates an output clock in the range of 2.5-5.75 GHz using a 125-MHz reference clock. At 5 GHz, it achieves an integrated jitter of 335 fsrms, while consuming 5.3 mW of power. This translates to the best reported figure-of-merit (FoM) of -242.4 dB for a ring-based ILCM at this high frequency.
KW - Delay line
KW - delay-locked loop (DLL)
KW - digital phase-locked loop (PLL)
KW - digitally controlled delay line (DCDL)
KW - digitally controlled oscillator (DCO)
KW - flicker noise
KW - frequency doubler
KW - injection locking
KW - injection-locked clock multiplier (ILCM)
KW - jitter
KW - least mean square (LMS)
KW - multiplying injection-locked oscillator (MILO)
KW - phase noise
KW - PLL
KW - reference doubler
KW - ring oscillator (RO)
UR - http://www.scopus.com/inward/record.url?scp=85068239463&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85068239463&partnerID=8YFLogxK
U2 - 10.1109/JSSC.2019.2904884
DO - 10.1109/JSSC.2019.2904884
M3 - Article
VL - 54
SP - 2049
EP - 2058
JO - IEEE Journal of Solid-State Circuits
JF - IEEE Journal of Solid-State Circuits
SN - 0018-9200
IS - 7
M1 - 8691469
ER -