Parasitic capacitance

About: Parasitic capacitance is a research topic. Over the lifetime, 10029 publications have been published within this topic receiving 110331 citations.

Ultra-low-capacitance flip-chip-bonded GaInAs PIN photodetector for long-wavelength high-data-rate fibre-optic systems

Abstract: A novel GaInAs substrate illuminated photodetector structure is reported for the 1.0–1.7 μm wavelength range with capacitance as low as 0.02 pF, packaging stray capacitance below 0.02 pF, 97% quantum efficiency and subnanoampere leakage current. The device is rugged, epoxy-free, does not use an integral fibre pig-tail and wire bonding to the detector chip is not required.

Switching and programming dynamics in phase-change memory cells

Abstract: Emerging phase-change memory (PCM) technology for non-volatile applications presents many potential advantages in terms of scalability, endurance and program/read speed. While several integration issues have still to be solved before achieving volume-production stage, the fundamental physics of chalcogenide switching and phase-change behaviour has still to be comprehensively understood. This paper provides an in-depth analysis of the switching and programming transient in PCM cells. It is shown that the cell parasitic capacitance can lead to a marked current overshoot in the programming transient. As evidenced by experiments, this overshoot is able to melt and quench the active material as in a reset operation. The parasitic reset results in a series distribution of crystalline and amorphous phases after program. The analysis of array cell capacitance instead indicates that no parasitic reset is to be expected, allowing for a localized crystallization during program, as previously obtained by numerical simulations.

X-ray tube bias supply

Abstract: 57 A power supply is switchable to apply a low kilovoltage and a relatively higher kilovoltage alternately to the anode of an x-ray tube that includes a filament and a control grid. A grid bias voltage generator uses an inverter driven in the kilohertz frequency range to feed the primary winding of a first transformer whose parasitic capacitance and inductance are used to produce a peak ac output voltage from the secondary of the first transformer at resonant frequency. The secondary output voltage is rectified and the resulting negative bias voltage is applied to the control grid synchronously with the high kilovoltage being applied to the anode so the x-ray tube current is then relatively low. A less negative or zero bias voltage is applied to the grid synchronously with the lower kilovoltage being applied to the anode so the x-ray tube current is then relatively high and substantially limited by the temperature and emissivity of the filament. A second transformer identical to the first one is used to sense the ac output voltage of the first one. A voltage-to-frequency converter switches the inverter. The resonant circuit ac output voltage sensed by the second transformer is rectified and compared with a selectable dc control signal and any resulting error signal is used to adjust the converter frequency and, hence, the inverter frequency so the bias on the x-ray tube grid voltage is proportional to the dc control signal level.

Active capacitance multipliers using current conveyors

Abstract: One of the most limiting problems in the design of integrated circuits is constituted by the realization of high valued capacitors, who have the heavy drawback of high occupation of silicon area. Moreover, in some sensor applications, it can be useful to deal with capacitance values higher than those normally given by capacitive sensors. In these cases, the use of capacitance multipliers can be very important. In this paper, we propose a novel principle of simple capacitance multipliers, by which it is possible to obtain higher capacitive values. Two solutions, the first using one CCII- with current gain and the second using two conventional CCIIs, are presented and analyzed. The effects of CCII non-idealities are also evaluated and discussed. Finally, SPICE simulations, which are in a close agreement with the analytical calculations, are also reported.

High-Power V-Band InGaAs/InP Photodiodes

Abstract: InGaAs/InP-modified uni-traveling carrier photodiodes with cliff layer were designed and fabricated for V-band (50-75 GHz) applications. The devices were flip-chip bonded on AlN submounts for efficient heat dissipation. A high-impedance transmission line was designed to compensate for the parasitic capacitance and enhance the bandwidth. Devices with 3-dB bandwidths of 50 and 65 GHz demonstrated high-output RF power of 20.3 and 15.9 dBm, respectively.