dr. An

Postdoc
Electronic Instrumentation (EI), Department of Microelectronics

Expertise: Ultrasound ASICs, precision analog circuits, and capacitive sensor interfaces

Biography

Jae-Sung An received a B.S. in Media Communications Engineering from Hanyang University in Seoul, Korea, in 2010. He recieved a Ph.D. Degree at Hanyang University, Seoul, Korea, in 2018. He worked in Leading UI as an analog engineer in 2018. He is working at TU Delft as an postdoctoral researcher. His research interests include high-precision analog integrated circuit design, driving and sensing schemes for capacitive touch systems with passive and active styli, fingerprint sensing systems, and ultrasound imaging systems. A capacitive touch system with multi-functional active stylus, which was designed by him, received two IEEE ISSCC presentations and demonstrations from 2017 to 2018.

Ultrasound Integrated Patch for Medical Diagnostics

In this project, we will develop flexible, programmable transducer modules for ultrasound body patches

  1. A 64-Channel Transmit Beamformer with ±30V Bipolar High-Voltage Pulsers for Catheter-Based Ultrasound Probes
    M. Tan; E. Kang; J.-S. An; Z. Y. Chang; P. Vince; T. Matéo; N. Sénégond; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 55, Issue 7, pp. 1796-1806, July 2020. DOI: 10.1109/JSSC.2020.2987719
    Abstract: ... This article presents a fully integrated 64-channel programmable ultrasound transmit beamformer for catheter-based ultrasound probes, designed to interface with a capacitive micro-machined ultrasound transducer (CMUT) array. The chip is equipped with programmable high-voltage (HV) pulsers that can generate ±30-V return-to-zero (RZ) and non-RZ pulses. The pulsers employ a compact back-to-back isolating HV switch topology that employs HV floating-gate drivers with only one HV MOS transistor each. Further die-size reduction is achieved by using the RZ switches also as the transmit/receive (T/R) needed to pass received echo signals to low-voltage receive circuitry. On-chip digital logic clocked at 200 MHz allows the pulse timing to be programmed with a resolution of 5 ns, while supporting pulses of 1 cycle up to 63 cycles. The chip has been implemented in 0.18-μm HV Bipolar-CMOS-DMOS (BCD) technology and occupies an area of 1.8 mm x 16.5 mm, suitable for integration into an 8-F catheter. Each pulser with embedded T/R switch and digital logic occupies only 0.167 mm². The pulser successfully drives an 18-pF transducer capacitance at pulse frequencies up to 9 MHz. The T/R switch has a measured ON-resistance of ~180 Ω . The acoustic results obtained in combination with a 7.5-MHz 64-element CMUT array demonstrate the ability to generate steered and focused acoustic beams.

  2. A Variable-Gain Low-Noise Transimpedance Amplifier for Miniature Ultrasound Probes
    E. Kang; M. Tan; J. S. An; Z. Y. Chang; P. Vince; N. Sénégond; T. Mateo; C. Meynier; M. A. P. Pertijs;
    IEEE Journal of Solid-State Circuits,
    Volume 55, Issue 12, pp. 3157--3168, December 2020. DOI: 10.1109/jssc.2020.3023618
    Abstract: ... This article presents a low-noise transimpedance amplifier (TIA) designed for miniature ultrasound probes. It provides continuously variable gain to compensate for the time-dependent attenuation of the received echo signal. This time-gain compensation (TGC) compresses the echo-signal dynamic range (DR) while avoiding imaging artifacts associated with discrete gain steps. Embedding the TGC function in the TIA reduces the output DR, saving power compared to prior solutions that apply TGC after the low-noise amplifier. The TIA employs a capacitive ladder feedback network and a current-steering circuit to obtain a linear-in-dB gain range of 37 dB. A variable-gain loop amplifier based on current-reuse stages maintains constant bandwidth in a power-efficient manner. The TIA has been integrated in a 64-channel ultrasound transceiver application-specific integrated circuit (ASIC) in a 180-nm BCDMOS process and occupies a die area of 0.12 mm². It achieves a gain error below ±1 dB and a 1.7 pA/√ Hz noise floor and consumes 5.2 mW from a ±0.9 V supply. B-mode images of a tissue-mimicking phantom are presented that show the benefits of the TGC scheme.

  3. A Capacitive Touch Chipset with 33.9dB Charge-Overflow Reduction using Amplitude-Modulated Multi-Frequency Excitation and Wireless Power and Data Transfer to an Active Stylus
    J.-S. An; J.-H. Ra; E. Kang; M. Pertijs; S.-H. Han;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 430-431, February 2020.

  4. A 2 pA/√Hz Transimpedance Amplifier for Miniature Ultrasound Probes with 36dB Continuous Time-Gain Compensation
    E. Kang; M. Tan; J. An; P. Vince; N. Sénégond; T. Mateo; Cyril Meynier; M. A. P. Pertijs;
    In Dig. Techn. Papers IEEE International Solid-State Circuits Conference (ISSCC),
    pp. 354-355, February 2020.

  5. Transverse-EPT: a local first order electrical properties tomography approach free of incident fields
    Reijer Leijsen; Xin An; Wyger Brink; Andrew Webb; Rob Remis;
    In Book of Abstracts ISMRM-Benelux: The 12th Annual Meeting of the ISMRM Benelux Chapter,
    Arnhem (The Netherlands), ISMRM-Benelux, pp. O87, January 2020.

  6. An Integrated Programmable High-Voltage Bipolar Pulser with Embedded Transmit/Receive Switch for Miniature Ultrasound Probes
    M. Tan; E. Kang; J.-S. An; Z. Y. Chang; P. Vince; N. Sénégond; M. A. P. Pertijs;
    IEEE Solid-State Circuits Letters,
    Volume 2, Issue 9, pp. 79-82, September 2019. DOI: 10.1109/LSSC.2019.2938141
    Abstract: ... This letter presents a compact programmable high-voltage (HV) pulser for ultrasound imaging, designed for driving capacitive micromachined ultrasonic transducers (CMUTs) in miniature ultrasound probes. To enable bipolar return-to-zero (RZ) pulsing and embedded transmit/receive switching, a compact back-to-back isolating HV switch is proposed that employs HV floating-gate drivers with only one HV MOS transistor each. The pulser can be digitally programmed to generate bipolar pulses with and without RZ, with a peak-to-peak swing up to 60 V, as well as negative and positive unipolar pulses. It can generate bursts of up to 63 pulses, with a maximum pulse frequency of 9 MHz for an 18-pF transducer capacitance. Realized in TSMC 0.18um HV BCD technology, the pulser occupies only 0.167mm2 . Electrical characterization results of the pulser, as well as acoustic results obtained in the combination with a 7.5-MHz CMUT transducer, are presented.

  7. An Integrated Programmable High-Voltage Bipolar Pulser with Embedded Transmit/Receive Switch for Miniature Ultrasound Probes
    M. Tan; E. Kang; J.-S. An; Z. Y. Chang; P. Vince; N. Sénégond; M. A. P. Pertijs;
    In Proc. European Solid-State Circuits Conference (ESSCIRC),
    pp. 325--328, October 2019.
    Abstract: ... This paper presents a compact programmable high-voltage (HV) pulser for ultrasound imaging, designed for driving capacitive micro-machined ultrasonic transducers (CMUTs) in miniature ultrasound probes. To enable bipolar return-to-zero pulsing and embedded transmit/receive switching, a compact back-to-back isolating HV switch is proposed that employs HV floating-gate drivers with only one HV MOS transistor each. The pulser can be digitally programmed to generate bipolar pulses with and without return-to-zero, with a peak-to-peak swing up to 60 V, as well as negative and positive unipolar pulses. It can generate bursts of up to 63 pulses, with a maximum pulse frequency of 9 MHz for an 18 pF transducer capacitance. Realized in TSMC 0.18 μm HV BCD technology, the pulser occupies only 0.167 mm2. Electrical characterization results of the pulser, as well as acoustic results obtained in combination with a 7.5-MHz CMUT transducer, are presented.

  8. AlN Piezoelectric Films for Sensing and Actuation
    Tran Trong An;
    PhD thesis, Delft University of Technology, 2014.
    document

  9. Towards the integration of carbon nanotubes as vias in monolithic three-dimensional integrated circuits
    S. Vollebregt; Chiaramonti; AN; J. van der Cingel; C.I.M. Beenakker; R. Ishihara;
    Japanese Journal of Applied Physics. Part 1, Regular Papers Brief Communications & Review Papers,
    Volume 52, Issue 1-5, 2013.

BibTeX support

Last updated: 4 Dec 2018

Jae-Sung An

MSc students