Jae-Myung Lim

This paper presents a feasibility study of wireless power and data transmission through an inductive link to a 1-mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> implant, to be used as a free-floating neural probe, distributed across a brain area of interest. The proposed structure utilizes a four-coil inductive link for back telemetry, shared with a three-coil link for wireless power transmission. We propose a design procedure for geometr

Having intravascular ultrasound (IVUS) imaging capability on guide wires used in cardiovascular interventions may eliminate the need for separate IVUS catheters and expand the use of IVUS in a larger portion of the vasculature. High frequency capacitive micro machined ultrasonic transducer (CMUT) arrays should be integrated with interface electronics and placed on the guide wire for this purpose. Besides small size, this system-on-a-chip (SoC) front-end should connect to the back-end imaging sys

In this article, we present a highly integrated guidewire ultrasound (US) imaging system-on-a-chip (GUISoC) for vascular imaging. The SoC consists of a 16-channel US transmitter (Tx) and receiver (Rx) electronics, on-chip power management IC (PMIC), and quadrature sampler. Using a synthetic aperture imaging algorithm, a Tx/Rx pair, connected to capacitive micromachined ultrasound transducers (CMUTs), can be activated at any time. The Tx generates acoustic waves by driving the CMUT, while the Rx

This paper presents the design procedure for a new multi-cycle resonance-based voltage boosting rectifier (MCRR) capable of delivering a desired amount of power to the load (PDL) at a designated high voltage (HV) through a loosely-coupled inductive link. This is achieved by shorting the receiver (Rx) LC-tank for several cycles to harvest and accumulate the wireless energy in the RX inductor before boosting the voltage by breaking the loop and transferring the energy to the load in a quarter cycl

This paper proposes a 7T2C pixel circuit for active-matrix organic light-emitting diode (AMOLED) displays using low-temperature poly-crystalline silicon (LTPS) thin-film transistors (TFTs) with two key features: high luminance uniformity and low flicker at a wide range of variable frame rates (VFRs). To achieve a high luminance uniformity, the proposed pixel circuit simultaneously compensates for the threshold voltage variation and subthreshold slope variation of the driving TFT with a sufficien

This paper proposes a multiphase resonance-based rectifier (MPRR), capable of delivering power to multiple loads with large difference in their output voltages. This behavior is particularly useful for wireless sensors and actuators, in which the micromachined transducer/actuator needs a high voltage to operate but the interface circuitry requires only a fraction of that voltage. This is achieved by shorting the receiver (Rx) L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="htt

A sensor interface circuit based on impulse radio pulse width modulation (IR-PWM) is presented for low power and high throughput wireless data acquisition systems (wDAQ) with extreme size and power constraints. Two triple-slope analog-to-time converters (ATC) convert two analog signals, each up to 5 MHz in bandwidth, into PWM signals, and an impulse radio (IR) transmitted (Tx) with an all-digital power amplifier (PA) combines them while preserving the timing information by transmitting impulses

When it is necessary to detect various physiological signals of the human body, clothing embroidered with near-field effect patterns can be used as a long-term power supply medium to supply power to long-distance transmitters and receivers to form a wireless power supply system. The proposed system uses an optimized parallel circuit to achieve a power transfer efficiency of more than five times higher than that of the existing series circuit. The power transfer efficiency of simultaneously suppl

A low-dropout (LDO) regulator controlled by an inverter-based amplifier is proposed to accomplish the latest processor power requirements. The proposed inverter-based amplifier provides a high DC gain in low-voltage operation. Furthermore, an auxiliary non-inverting amplifier is adopted to regulate the wider output voltage and enhance power supply rejection ratio (PSRR) performance. The proposed LDO regulator has been implemented in a 28-nm CMOS process and provides an output range of 0.2-1.05 V

This letter introduces a novel battery charging solution for multiple wearable devices. Using conductive textile interwoven into clothing, our system provides the convenience of on-body charging and the capacity to charge multiple devices concurrently from a single charger. The uniqueness of our approach lies in its capability to achieve load-independent constant current (CC) and constant voltage (CV) charging using a minimalistic component configuration and permitting each device to independent

This paper presents the carrier harmonic modulation (CHM) for near-field data communication during wireless power transmission. The proposed CHM does not increase the coil dimension, and an additional data driver is not required. Compare to conventional modulation techniques such as frequency-shift keying (FSK) and amplitude-shift keying (ASK), the power delivered to the load (PDL) of CHM is independent of the data transmission. The prototype CHM provides a data rate of 1.1 Mbps while the power

We present a system-on-a-chip (SoC) for use in high-frequency capacitive micromachined ultrasonic transducer (CMUT) imaging systems. This SoC consists of trans-impedance amplifiers (TIA), delay locked loop (DLL) based clock multiplier, quadrature sampler, and pulse width modulator (PWM). The SoC down converts RF echo signal to baseband by quadrature sampling which facilitates modulation. To send data through a 1.6 m wire in the catheter which has limited bandwidth and is vulnerable to noise, the

This letter proposes a 6T2C pixel circuit designed for LTPS-based AMOLED displays to improve luminance uniformity and reduce flicker across a wide range of variable refresh rates (VRRs). The proposed circuit employs a two-step compensation method to address variations in the threshold voltage and subthreshold slope of driving thin-film transistors (TFTs), improving luminance uniformity. Additionally, it minimizes the hysteresis effect of TFTs using an inducing hole-trapping technique, resulting

A system-on-a-chip (SoC) for interfacing with a high frequency capacitive micromachined ultrasound transducer (CMUT) imaging array is presented at the post-layout simulation level. The SoC receives high and low voltage supply and clock from external sources and transfers the RF echo signal directly through a single wire. It occupies a 1.26 mm2 chip area in a 0.18-μm high voltage CMOS process and consumes 11.2 mW and 4.5 mW from the 1.8 V and 46 V supplies on the receiver (Rx) and transmitter (Tx