Rajesh Kumar Kumar Sirvi

Mr. Rajesh Kumar Kumar Sirvi


Research Focus & Metrics

Academic Career Length

1Year (2026-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 July 2026 in Preprints.org
Verified
Preprint
Open access
PDF file
SKSaeid Karimpour
Saeid Karimpour
EDEmmanuel Nti Darko
Emmanuel Nti Darko
BABabar Ali
Babar Ali
RSRajesh Kumar Kumar Sirvi
Rajesh Kumar Kumar Sirvi
DCDegang Chen
Degang Chen
The first divider in an integer- or fractional-N frequency synthesizer runs at the full oscillator frequency and so constrains both the speed and the power of the loop. Current-mode logic (CML) reaches high speed but draws a constant bias current independent of activity, whereas a fully static-CMOS (all-digital) divider draws only dynamic and leakage current at the cost of much greater timing sensitivity to process, voltage, and temperature (PVT) variation. This paper presents a wide-range all-digital multi-modulus divider in a 22 nm fully depleted silicon-on-insulator (FDSOI) technology, characterized entirely by post-layout and Monte Carlo simulation, together with the methodology that makes the timing-sensitive digital approach robust. The all-digital chain exhibits three PVT failure modes, setup at the slow-hot corner, hold at the fast-cold corner, and internal duty-cycle collapse at the skewed corners; each is predicted analytically and closed by a three-method scheme built on the FDSOI back gate, a per-stage delay trim, and a systematic integral-nonlinearity trim. The divider covers N=8 to 127 at up to 39.5 GHz at the typical corner, with every process corner held at or above 35 GHz by back-gate compensation, the highest speed among the compared dividers and the only one with explicit PVT compensation. At the 33 GHz target it consumes 5.3 mW at N=127 (6.2 GHz/mW) with an activity-scaling supply current, benchmarked against the measured power of published CML dividers. Per-die body-bias and trim raise the Monte Carlo yield from 78% to 99.3%, at 150 fs additive jitter, in a compact 0.005 mm2 core.

7 September 2026 in Electronics
Verified
Journal Article
Open access
PDF file
SKSaeid Karimpour
Saeid Karimpour
EDEmmanuel Nti Darko
Emmanuel Nti Darko
BABabar Ali
Babar Ali
RSRajesh Kumar Kumar Sirvi
Rajesh Kumar Kumar Sirvi
DCDegang Chen
Degang Chen
The first divider in the feedback path of a frequency synthesizer runs at the full oscillator frequency and so constrains the speed and the power of the loop. Current-mode logic reaches high speed but draws a constant bias current independent of switching activity, whereas an all-digital, fully static-CMOS divider draws only dynamic and leakage current at the cost of far greater timing sensitivity to process, voltage, and temperature (PVT) variation. This paper presents a wide-range all-digital multi-modulus divider in 22 nm fully depleted silicon-on-insulator (FDSOI) technology, together with the methodology that makes the digital approach robust. The chain exhibits three distinct PVT failure modes, setup at the slow corners, hold at the fast-cold corner, and collapse of the internal clock duty cycle at the skewed corners; each is identified analytically and closed by a scheme combining back-gate body bias, a per-stage programmable delay trim, and a systematic integral-nonlinearity trim. Characterization is by post-layout simulation over a 45-point corner matrix, with the applied back-gate rail voltages and trim codes reported for every point. The divider covers N= 8 to 127, reaches 39.5 GHz at the typical corner, and holds a worst-case 33.0 GHz across the corner box against a 33 GHz target that the uncompensated chain misses at the slow and skewed low-supply corners (SS, SF, and FS at 0.72 V). A paired Monte Carlo campaign of 100 samples with process and mismatch variation, run at the binding corner, raises the yield at the target from 39% uncompensated to 72% with a single global back-gate setting and 99% with a per-die setting. At the target the divider consumes 5.3 mW at N=127 (6.2 GHz/mW) with 35.2 fs of additive jitter in a 0.005 mm2 core. The bias and trim settings are chosen by an external search and applied as fixed per-corner values; the monitors, controller, and bias generator that an autonomous implementation would require are specified but not designed, so the work demonstrates externally calibrated corner closure rather than a self-contained compensation system.