Wanyeong Jung

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Recent advances in low-power circuits have enabled mm-scale wireless systems [1] for wireless sensor networks and implantable devices, among other applications. Energy harvesting is an attractive way to power such systems due to limited energy capacity of batteries at these form factors. However, the same size limitation restricts the amount of harvested(More)
This paper presents a fully integrated energy harvester that maintains 35% end-to-end efficiency when harvesting from a 0.84 mm solar cell in low light condition of 260 lux, converting 7 nW input power from 250 mV to 4 V. Newly proposed self-oscillating switched-capacitor (SC) DC-DC voltage doublers are cascaded to form a complete harvester, with(More)
An incremental zoom-in capacitance-to-digital converter (CDC) is proposed. By using a 9b SAR, the OSR can be reduced to only 32, significantly improving conversion energy. We show how the OTA in the SAR is bypassed for the CDC further reducing energy and propose a novel matrix based 512-element unit-cap structure for dynamic element matching. The CDC(More)
This work presents a dual-slope capacitance to digital converter for pressure sensing. The design uses base capacitance subtraction with a configurable capacitor bank and dual precision comparators to improve energy efficiency, consuming 110nW with 9.7b ENOB and 0.85pJ/conv·step FoM. The converter is integrated with a pressure transducer, battery,(More)
As Internet-of-Things (IoT) systems proliferate, there is a greater demand for small and efficient power management units. Fully integrated switched-capacitor (SC) DC-DC converters are promising candidates due to their small form factor and low quiescent power, aided by dynamic activity scaling [1-3]. However, they offer a limited number of conversion(More)
Capacitance sensors are widely used to measure various physical quantities, including position, pressure, and concentration of certain chemicals [1-6]. Integrating capacitive sensors into a small wireless sensor system is challenging due to their large power consumption relative to the total system power/energy budget, which can be as low as a few nW [4].(More)
We present an 8-bit sub-ranging SAR ADC designed for bursty signals having long time periods with small code spread. A modified capacitive-DAC (CDAC) saves previous sample's MSB voltage and reuses it throughout subsequent conversions. This prevents unnecessary switching of large MSB capacitors as well as conversion cycles, reducing energy consumed in the(More)