Profile

Analog and mixed-signal IC designer with a PhD in microelectronics and more than fifteen years in CMOS silicon. I work at transistor level on data converters and the analog blocks around them — sampling networks, comparators, references and biasing — and carry blocks from architecture and behavioural modelling through schematic design, PVT and Monte Carlo verification, layout review, tape-out and bench characterisation.

Appointments

2023 — Present

Analog/Mixed-Signal Design Engineer

Analog Devices · Wilmington, Massachusetts
  • Transistor-level design of analog and mixed-signal blocks for precision data-acquisition products: converter cores, sampling networks, comparators, and reference and bias circuits.
  • Block ownership end to end — architecture definition and behavioural modelling, schematic design, simulation across PVT corners and Monte Carlo, layout review, tape-out and silicon characterisation.
  • Advanced-node work in FinFET and SOI processes, including noise, matching and reference-settling budgets for high-resolution converters.
2016 — 2023

Senior Researcher

INESC-ID · Lisbon, Portugal
  • Led analog and mixed-signal circuit research in the Analog and Mixed-Signal Circuits group, focused on low-voltage low-power SAR and charge-sharing ADCs, comparators and calibration techniques.
  • Supervised and co-supervised student research; designed, taped out and characterised prototype converters in processes from 0.35 µm to 28 nm.
  • Member of the Scientific Council, 2017 – 2023: institutional research strategy and internal review.
2010 — 2016

Research Assistant

INESC-ID · Lisbon, Portugal

Doctoral and pre-doctoral work on charge-sharing SAR ADCs: architecture analysis, MOSCAP-based DACs, comparator offset auto-zeroing and self-timed SAR control, validated in four fabricated prototypes.

2018

Visiting Scholar

Delft University of Technology · Delft, Netherlands
2009

Intern Researcher

Gwangju Institute of Science & Technology · Gwangju, South Korea

Education

2012 — 2016

PhD, Electrical and Computer Engineering (with honors)

Instituto Superior Técnico, Universidade de Lisboa

Microelectronics. Thesis on charge-sharing SAR ADCs for low-voltage low-power applications, later published as a Springer monograph. Awarded with distinction and honour.

2010 — 2011

MSc, Computer Science

Universidade Federal de Santa Maria, Brazil

Thesis on techniques for power reduction in SAR ADCs.

2005 — 2009

BSc, Electrical Engineering

Universidade Federal de Santa Maria, Brazil

Expertise

Circuits
  • SAR, charge-sharing and charge-redistribution ADCs
  • Sampling networks, track-and-hold, bootstrapped switches
  • Dynamic comparators and latches; offset and noise calibration
  • References, biasing and reference buffers
  • Relaxation and quadrature oscillators
  • Magnetoresistive sensor front-ends; multi-valued CMOS logic
Methods
  • Low-voltage, low-power CMOS design
  • Architecture definition and behavioural modelling
  • PVT, corner and Monte Carlo verification
  • Noise, matching and settling analysis; PSS/PXF/PNOISE for comparators
  • Simulation-based sizing and optimisation
  • Layout review, tape-out, bring-up and bench characterisation
Tools
  • Cadence Virtuoso, Spectre and the analog verification flow
  • Python for modelling, test automation and data analysis
  • Lab characterisation of converters: static and dynamic linearity
Languages
  • English — fluent
  • Portuguese — native

Silicon

Chips taped out across eight process generations, in bulk CMOS, SOI and FinFET.

0.5 µm0.35 µm0.18 µm0.13 µm65 nm40 nm22 nm5 nm

Books

Monograph · Springer

Charge-Sharing SAR ADCs for Low-Voltage Low-Power Applications

T. Rabuske and J. Fernandes · Analog Circuits and Signal Processing series · Springer, Cham, 2017 · 10.1007/978-3-319-39624-8

A full treatment of the charge-sharing SAR topology: the mechanisms that limit its performance — capacitor mismatch, comparator offset and noise — with closed-form analysis, mitigation techniques, and four fabricated prototypes operating from 0.35 V to 0.6 V.

  1. T. Rabuske, Conversores A/D SAR por Entrelaçamento no Tempo em Tecnologia CMOS 130 nm (in Portuguese). Novas Edições Acadêmicas, 2016.
  2. J. Silva, D. Oliveira, D. M. Caetano, T. Rabuske and J. Fernandes, “Variable Bandwidth Chopper Amplifier for Eddy-Current Non-Destructive Testing,” book chapter, 2017. DOI 10.3233/978-1-61499-767-2-187. · doi

Journal papers

  1. A 0.3-mm² 1.3 µW Wireless Monitoring System IC for Hermeticity Testing of Biomedical Implants
    G. Rodrigues, T. Rabuske and J. Fernandes · IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 72, no. 8, pp. 3911–3923, 2025 · doi
  2. Integrated Circuit for Magnetic Encoder Sensing in TMR-Based Industrial Positioning System
    J. Silva, D. M. Caetano, T. Rabuske, S. Cardoso, M. Piedade and J. Fernandes · IEEE Transactions on Industrial Electronics, vol. 71, no. 8, pp. 9904–9913, 2024 · doi
  3. Maximizing Energy Harvesting in a Miniaturized Implant With an Integrated Coil Receiver
    G. Rodrigues, J. Silva, H. I. Busse, D. M. Caetano, J. Fernandes and T. Rabuske · IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 70, no. 10, pp. 3762–3766, 2023 · doi
  4. Artificial Neural Networks for GMR-Based Magnetic Cytometry
    D. M. Caetano, R. Afonso, A. R. Soares, J. Silva, H. I. Busse, V. Silvério, T. Rabuske, G. N. Tavares, J. Fernandes and S. Cardoso · IEEE Transactions on Instrumentation and Measurement, vol. 72, pp. 1–11, 2023 · doi
  5. Calibrating Amplifiers Nonlinearity Using Comparator-Based ADCs
    F. A. Rabuske, T. Rabuske, S. Liu and J. Fernandes · IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 67, no. 3, pp. 435–439, 2020 · doi
  6. High-Resolution Nondestructive Test Probes Based on Magnetoresistive Sensors
    D. M. Caetano, T. Rabuske, J. Fernandes, M. Pelkner, C. Fermon, S. Cardoso, B. Ribes, F. Franco, J. Paul, M. S. Piedade and P. P. Freitas · IEEE Transactions on Industrial Electronics, vol. 66, no. 9, pp. 7326–7337, 2019 · doi
  7. Analysis and Background Self-Calibration of Comparator Offset in Loop-Unrolled SAR ADCs
    S. Liu, T. Rabuske, J. Paramesh, L. Pileggi and J. Fernandes · IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 65, no. 2, pp. 458–470, 2018 · doi
  8. A 5-bit 300–900-MS/s 0.8–1.2-V Supply Voltage ADC With Background Self-Calibration
    F. A. Rabuske, T. Rabuske and J. Fernandes · IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 64, no. 1, pp. 1–5, 2017 · doi
  9. Effect of Comparator Offset on the Linearity of Charge Sharing ADCs
    T. Rabuske and J. Fernandes · Analog Integrated Circuits and Signal Processing, vol. 90, no. 1, pp. 9–16, 2017 · doi
  10. A 2.4 GHz high-performance CMOS differential quadrature relaxation oscillator
    E. Ortigueira, T. Rabuske, L. B. Oliveira, J. Fernandes and M. M. Silva · Analog Integrated Circuits and Signal Processing, vol. 90, no. 1, 2017 · doi
  11. A SAR ADC With a MOSCAP-DAC
    T. Rabuske and J. Fernandes · IEEE Journal of Solid-State Circuits, vol. 51, no. 6, pp. 1410–1422, 2016. Most-downloaded JSSC paper, June 2016 · doi
  12. An 8-bit 0.35-V 5.04-fJ/conversion-step SAR ADC With Background Self-Calibration of Comparator Offset
    T. Rabuske, F. A. Rabuske, J. Fernandes and C. Rodrigues · IEEE Transactions on Very Large Scale Integration (VLSI) Systems, vol. 23, no. 7, pp. 1301–1307, 2015 · doi
  13. Quaternary Logic Lookup Table in Standard CMOS
    D. Brito, T. Rabuske, J. Fernandes, P. Flores and J. Monteiro · IEEE Transactions on Very Large Scale Integration (VLSI) Systems, vol. 23, no. 2, pp. 306–316, 2015 · doi
  14. Noise-aware simulation-based sizing and optimization of clocked comparators
    T. Rabuske and J. Fernandes · Analog Integrated Circuits and Signal Processing, vol. 81, no. 3, pp. 723–728, 2014 · doi
  15. Comparator-based binary-search ADC architectures for UWB receivers
    T. Rabuske, F. A. Rabuske, J. Fernandes, C. Rodrigues and D. Brito · Analog Integrated Circuits and Signal Processing, vol. 77, no. 3, pp. 471–482, 2013 · doi
  16. A 5 MSps 8-bit SAR ADC with single-ended or differential input
    T. Rabuske, C. Rodrigues and S. Nooshabadi · Microelectronics Journal, vol. 43, no. 10, pp. 680–686, 2012 · doi
  17. A 54.2 µW 5 MSps 9-bit ultra-low-energy analog-to-digital converter in 180 nm technology
    T. Rabuske, S. Nooshabadi and C. Rodrigues · Analog Integrated Circuits and Signal Processing, vol. 72, no. 1, pp. 37–46, 2011 · doi

Conference papers

  1. Stacked Ring Oscillators with Fractional Injection Lock
    G. Rodrigues, R. Borralho, T. Rabuske and J. Fernandes · IEEE International Symposium on Circuits and Systems (ISCAS), 2025 · doi
  2. A Small-Area Current-Mode Input ΣΔ Modulator for Under-the-Sensors ADC Arrays
    H. I. Busse, T. Rabuske, M. Silva, G. Rodrigues, D. M. Caetano, M. B. Santos and J. Fernandes · Conference on Design of Circuits and Integrated Systems (DCIS), 2024 · doi
  3. An On-Chip Clock Generation Circuit for Smart Catheters
    D. Brito, J. Silva, G. Rodrigues, A. Pinto, J. Fernandes and T. Rabuske · IEEE International Symposium on Circuits and Systems (ISCAS), 2021 · doi
  4. A Temperature-Compensated 57 ppm/°C 10 MHz, 2.4 µW Stacked Ring Oscillator
    G. Rodrigues, D. Brito, H. I. Busse, J. Fernandes, J. Silva and T. Rabuske · IEEE International Symposium on Circuits and Systems (ISCAS), 2021 · doi
  5. Towards a Wireless System that Can Monitor the Encapsulation of mm-sized Active Implants in vivo for Bioelectronic Medicine
    G. Rodrigues, M. Neca, J. Silva, D. Brito, T. Rabuske, J. Fernandes, R. Mohrlok, C. Jeschke, J. Meents, K. Nanbakhsh and V. Giagka · IEEE EMBS Conference on Neural Engineering (NER), 2021, pp. 981–984 · doi
  6. A Biomedical Imaging System Based on an Integrated Array of Magnetoresistive Sensors
    T. Rabuske, M. Silva, D. Brito et al. · IEEE International New Circuits and Systems Conference (NEWCAS), 2021, pp. 1–4 · doi
  7. Methods for Fast Characterization of Noise and Offset in Dynamic Comparators
    J. Silva, D. Brito, G. Rodrigues, T. Rabuske, A. C. Pinto and J. Fernandes · IEEE International New Circuits and Systems Conference (NEWCAS), 2021, pp. 1–4 · doi
  8. Polymath: A Platform for Rapid Application Development of Modular EDA Tools
    T. Rabuske · IEEE International Symposium on Circuits and Systems (ISCAS), 2020, pp. 1–5 · doi
  9. A Sub-µW 3–10 MHz Stacked Oscillator with a Duty-Cycle Calibrated Level Shifter
    G. Rodrigues, D. M. Caetano, D. Brito, J. Fernandes and T. Rabuske · IEEE International Symposium on Circuits and Systems (ISCAS), 2020, pp. 1–5 · doi
  10. Injection Locked Oscillators with Current Reuse
    M. Benido, T. Rabuske and J. Fernandes · IEEE International Symposium on Circuits and Systems (ISCAS), 2019, pp. 1–4 · doi
  11. A Small-Footprint Quasi-Passive 1st-Order ΣΔ Modulator
    G. Rodrigues, J. Fernandes and T. Rabuske · IEEE International Symposium on Circuits and Systems (ISCAS), 2019, pp. 1–5 · doi
  12. A 125 MS/s 10.4 ENOB 10.1 fJ/conv-step Multi-Comparator SAR ADC with Comparator Noise Scaling in 65 nm CMOS
    S. Liu, J. Paramesh, L. Pileggi, T. Rabuske and J. Fernandes · ESSCIRC, 2018, pp. 22–25 · doi
  13. Tunable kΩ to GΩ pseudo-resistor with bootstrapping technique
    D. M. Caetano, D. Oliveira, J. Silva, T. Rabuske and J. Fernandes · IEEE International Midwest Symposium on Circuits and Systems (MWSCAS), 2017, pp. 1569–1572 · doi
  14. Variable Bandwidth Chopper Amplifier for Eddy-Current Non-Destructive Testing
    J. Silva, D. Oliveira, D. M. Caetano, J. Fernandes and T. Rabuske · International Workshop on Electromagnetic Nondestructive Evaluation (ENDE), 2016
  15. A 12-Bit SAR ADC with Background Self-Calibration Based on a MOSCAP-DAC with Dynamic Body-Biasing
    T. Rabuske and J. Fernandes · IEEE International Symposium on Circuits and Systems (ISCAS), 2016 · doi
  16. Fast settling VGA for eddy-currents non-destructive testing with an array of magneto-resistors
    D. M. Caetano, F. A. Rabuske, D. Oliveira, T. Rabuske and J. Fernandes · Conference on PhD Research in Microelectronics and Electronics (PRIME), 2016 · doi
  17. A 9-b 0.4-V charge-mode SAR ADC with 1.6-V input swing and a MOSCAP-only DAC
    T. Rabuske and J. Fernandes · ESSCIRC, 2015, pp. 311–314 · doi
  18. An efficient RF power harvester for low input power with reduced dead-zone
    H. Gonçalves, J. Fernandes, T. Rabuske and M. Martins · IEEE International Symposium on Circuits and Systems (ISCAS), 2014 · doi
  19. Quadrature relaxation oscillator with FoM of −165 dBc/Hz
    E. Ortigueira, T. Rabuske, L. B. Oliveira, J. Fernandes and M. M. Silva · IEEE International Symposium on Circuits and Systems (ISCAS), 2014 · doi
  20. A sub-ranging 2-step 7-bit self-calibrated comparator-based binary-search ADC
    F. A. Rabuske, T. Rabuske and J. Fernandes · IEEE International Symposium on Circuits and Systems (ISCAS), 2014 · doi
  21. A self-calibrated 10-bit 1 MSps SAR ADC with reduced-voltage charge-sharing DAC
    T. Rabuske, J. Fernandes, F. A. Rabuske, C. Rodrigues and M. B. Santos · IEEE International Symposium on Circuits and Systems (ISCAS), 2013, pp. 2452–2455 · doi
  22. A 5-bit 1.5 GSps calibration-less binary-search ADC using threshold-reconfigurable comparators
    T. Rabuske, F. A. Rabuske, J. Fernandes and C. Rodrigues · IEEE International Symposium on Circuits and Systems (ISCAS), 2013 · doi
  23. An IR-UWB transmitter with digital pulse duration control
    D. Correia, M. dal Alba, M. A. Martins, T. Rabuske, C. Rodrigues and J. Fernandes · IEEE International Symposium on Circuits and Systems (ISCAS), 2012, pp. 233–236 · doi
  24. PyCO: A parallel genetic algorithm optimization tool for analog circuits
    T. Rabuske, R. Pinheiro, J. Fernandes and C. Rodrigues · IEEE International Symposium on Circuits and Systems (ISCAS), 2012 · doi
  25. A 749 nW 1 MSps 8-bit SAR ADC at 0.5 V employing boosted switches
    T. Rabuske, J. Fernandes, S. Nooshabadi, C. Rodrigues and F. A. Rabuske · IEEE International Conference on Electronics, Circuits and Systems (ICECS), 2012 · doi
  26. A 4-bit 1.5 GSps 4.2 mW comparator-based binary-search ADC in 90 nm
    T. Rabuske, F. A. Rabuske, J. Fernandes and C. Rodrigues · IEEE International Conference on Electronics, Circuits and Systems (ICECS), 2012 · doi
  27. A track-and-hold for single-ended or differential input with adjustable output common mode
    T. Rabuske, C. Rodrigues and S. Nooshabadi · IEEE International Midwest Symposium on Circuits and Systems (MWSCAS), 2011 · doi
  28. An energy-efficient 1 MSps 7 µW 11.9 fJ/conversion-step 10-bit SAR ADC in 90 nm
    T. Rabuske, C. Rodrigues and S. Nooshabadi · IEEE International Symposium on Circuits and Systems (ISCAS), 2011
  29. A novel energy-efficient digital controller for charge-sharing successive-approximation ADCs
    T. Rabuske, F. A. Rabuske and C. Rodrigues · IEEE Latin American Symposium on Circuits and Systems (LASCAS), 2011
  30. Distributed version control as a tool to increase productivity in analog and mixed-signal design
    R. Pinheiro, T. Rabuske and C. Rodrigues · Iberchip, 2011
  31. An energy-efficient successive-approximation register analog-to-digital converter in 180 nm
    T. Rabuske and S. Nooshabadi · IEEE Asia Pacific Conference on Circuits and Systems (APCCAS), 2010 · doi

Patents

“Method for detection and classification of non-periodic signals and the respective system that implements it,” 2021.

Service & community

2018 — Present

Member, Analog Signal Processing Technical Committee

IEEE Circuits and Systems Society

Review and programme work in analog signal processing for CASS conferences and transactions.

2017 — 2023

Member, Scientific Council

INESC-ID, Lisbon
Ongoing

Reviewer

IEEE Journal of Solid-State Circuits, Transactions on Circuits and Systems I and II, Transactions on VLSI Systems, and CASS conferences.

Projects led

2018 — 2021

Position II — intravascular ultrasound catheter chip

INESC-ID with Philips Medical Systems · EU co-funded

System architect and technical lead for a TSMC 40 nm chip under severe area and self-heating constraints: analog front-end with filter and amplifier, LDOs with ultra-wideband PSR, configurable clock generation and a 10-bit 80 MSps ADC. Derived block specifications, ran the floorplan, designed the LDO, class-AB opamps and current and voltage references myself, and supervised three PhD candidates and two post-docs on the ADC, LC oscillator, fourth-order Bessel filter, SPI controller and the FPGA-based test system.

2018 — 2021

MagScopy — magnetic imaging for cancer-cell detection

System architect for a chip combining a conventional analog front-end — filtering, amplification, digitisation — with a 64×64 array of magnetic sensors post-processed on top of the CMOS die by project partners. Circuit design and layout carried out by the team under supervision.

2018 — 2021

StarChip — smart tubular devices for lab-on-chip

Planned the system and derived block-level specifications for a multi-channel chip of analog front-ends and 12-bit SAR ADCs; supervised all design activities.

2016 — 2018

TumaPos — self-characterising sensor interface chip

Industry contract, Germany

Architect and principal designer of a chip, test board and control software: offset-correction DAC, variable-gain instrumentation amplifier, second-order anti-aliasing filter with class-AB opamps, a 12-bit 2 MSps SAR ADC and an SPI-controlled digital block.

Awards & honours

2018, 2019
Finalist, INESC-ID Best Young Researcher Award
2016
PhD awarded with merits and honours, Instituto Superior Técnico, Universidade de Lisboa
2016
Finalist, Prof. Abreu Faro Prize for the best PhD thesis of Universidade de Lisboa
2015, 2016
Finalist, INESC-ID Best PhD Candidate Award
2016
Most-downloaded paper of the month, IEEE Journal of Solid-State Circuits — and 49th most downloaded across IEEE Xplore, June 2016

Advising & invited talks

(Co-)advised six doctoral candidates and ten MSc students at Instituto Superior Técnico and INESC-ID, 2017 – 2023.

2019
“Designing ADCs for the IoT: Architectures, Techniques and Tools,” IEEE Seasonal School on Circuits and Systems for IoT
2019
“Projeto de ADCs para a Internet das Coisas,” IEEE CASS Tech Talk, UFPel