85 research outputs found
A 25A Hybrid Magnetic Current Sensor with 64mA Resolution, 1.8MHz Bandwidth, and a Gain Drift Compensation Scheme
No full textMagnetic current sensors are used in switched-mode power supplies and motor drivers, where both galvanic isolation and wide bandwidth (BW) are desired. In CMOS, Hall-effect sensors are widely used, but their resistance results in a fundamental trade-off between BW and resolution. Coils have a differentiating characteristic and so can achieve much wider BW and resolution, but cannot sense DC.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
23.3 A 51A Hybrid Magnetic Current Sensor with a Dual Differential DC Servo Loop and 43mA<sub>rms</sub>Resolution in a 5MHz Bandwidth
No full textMagnetic current sensors are widely used in applications where galvanic isolation and wide bandwidth (BW) are desired, such as in switched-mode power supplies and motor drivers. By using Hall plates for low frequencies and pick-up coils for high frequencies, hybrid magnetic sensors can achieve high resolution (tens of textmA) over a wide frequency range (up to 15MHz) [1]-[3]. However, previous designs exhibit either poor gain flatness over frequency or limited energy efficiency. This work presents a hybrid magnetic current sensor that textachievespm 1. 1% gain flatness, which is 3times better than prior art [1]-[3]. Its energy efficiency is also 11times better than the state-of-the-art [1], [4], [5].Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Microelectronic
A Hybrid Magnetic Current Sensor With a Dual Differential DC Servo Loop
No full textThis article presents a hybrid magnetic current sensor for contactless current measurement. Pick-up coils and Hall plates are employed to sense the high and low-frequency fields, respectively, generated by a current-carrying conductor. Due to the differentiating characteristic of the pick-up coils, a flat frequency response can then be obtained by summing the outputs of the coil and the Hall paths and passing the result through a 1st-order low-pass filter (LPF). For maximum resolution, the LPF corner frequency (2 kHz) is set such that the noise contribution of each path is equal. To suppress the coil-path offset without the use of large ac coupling capacitors, an area-efficient dual dc servo loop (D3SL) is used. This effectively suppresses the coil-path offset, resulting in a total offset of 73 μT , which is mainly dominated by the Hall path. Fabricated in a standard 0.18-μm CMOS process, the current sensor occupies 3.9 mm2 and draws 7.1 mA from a 1.8 V supply. It achieves 43 mA resolution in a 5 MHz bandwidth, which is 1.5 × better than the state-of-the-art hybrid sensors. It also achieves the lowest energy efficiency FoM (3.5 ×) among CMOS magnetic current sensors.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationElectronic Components, Technology and MaterialsMicroelectronic
A Hybrid Magnetic Current Sensor With a Multiplexed Ripple-Reduction Loop
No full textThis article presents a hybrid magnetic current sensor for galvanically isolated measurements. It consists of a CMOS chip that senses the magnetic field generated by current flowing through a lead-frame-based current rail. Hall plates and coils are used to sense low-frequency (dc to 10 kHz) and high-frequency (10 kHz to 5 MHz) magnetic fields, respectively. With the help of on- chip calibration coils, the biasing current of the Hall plates is trimmed to match the sensitivity of the Hall and coil signal paths. The sensitivity drift of the coil path with temperature is compensated by using temperature-dependent gain-setting resistors, while the drift of the Hall path is compensated by biasing the Hall plates with a proportional- to-absolute-temperature (PTAT) current. The resulting sensitivity drift is less than 9% from-40 °C to 80 °C. The offset of the Hall plates is reduced by the current spinning technique, and the resulting ripple is suppressed by a multiplexed ripple-reduction loop (MMRL). Fabricated in a standard 0.18-μm CMOS process, the current sensor occupies 4.6 mm2 and draws 7.8 mA from a 1.8-V supply. It achieves a gain variation of only ±2% in a 5-MHz BW. It also achieves high energy efficiency, with an figure of merit (FoM) of 1.6 fW/Hz.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
Hyperglycemia-induced thrombin formation in diabetes. The possible role of oxidative stress
No full textThinking the unthinkable: Facing maternal abuse.
No full textThis paper describes how the radical concept of maternal perversion first presented by Estela Welldon (1988) informs the psychotherapeutic assessment and treatment of female inpatients within forensic services and of women in the community who commit acts of violence. It presents a model of the psychology of female violence that the author describes as 'crimes against the body'. The paper offers clinical evidence for Welldon's model of female perversion in forensic settings and provides an extended clinical illustration of psychotherapeutic work, when the therapist was pregnant, with a woman who killed her child
Cylinder Pressure-based Functions: Overview, Benefits and Algorithm Considerations
No full textThe strategies adopted to control the combustion in Diesel applications play a key
role when dealing with current and future requirements of the automotive market for
Diesel powertrain systems. Direct measurement of the combustion process, e.g. by
means of in-cylinder pressure sensor, offers the possibility to achieve the target
“quasi” automatically all over the vehicle lifetime in widely different operating
conditions. Beside the traditional combustion control in closed loop (i.e. based on
inner torque and/or combustion timing), the exploitation of in-cylinder pressure signal
offers a variety of possible further applications, e.g. smart detection of Diesel fuel
quality variation, control of combustion noise, modeling engine exhaust emission
(e.g. NOx).
In this contribution we like to address two main topics. A) an overview about the ongoing
cylinder pressure based function development activities is given and the
respective benefits are illustrated showing some experimental results. B) Additionally
we like to present the results of recent developments regarding efficient
implementations of some cylinder pressure based features helping to limit the impact of these new functionalities on ECU resources
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