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Author

Ahmed Rahali

Other affiliations: SIDI
Bio: Ahmed Rahali is an academic researcher from Sidi Mohamed Ben Abdellah University. The author has contributed to research in topics: Voltage & Battery charger. The author has an hindex of 1, co-authored 6 publications receiving 4 citations. Previous affiliations of Ahmed Rahali include SIDI.

Papers
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Journal ArticleDOI
TL;DR: A 2 MHz on-off keying (OOK) transmitter/receiver for inductive power and data transmission for biomedical implant system is presented and a wireless data and power transfer link is implemented which can transmit data with data rate 1Mbps and bit error rate of 10-5.
Abstract: In this work a 2 MHz on-off keying (OOK) transmitter/receiver for inductive power and data transmission for biomedical implant system is presented. Inductive link, driven by a Class E power amplifier (PA) is the most PA used to transfer data and power to the internal part of biomedical implant system. Proposed transmitter consists of a digital control oscillator (DCO) and a class E PA which uses OOK modulation to transfer both data and power to a biomedical implant. In proposing OOK transmitter when the transmitter sends binary value “0” the DCO and PA are turned off. With this architecture and 2 MHz carrier wave we have implemented a wireless data and power transfer link which can transmit data with data rate 1Mbps and bit error rate (BER) of 10-5. The efficiency of power transfer is 42% with a 12.7 uH transmitter coil and a 2.4 uH receiver coil and the power delivered to the load is about 104.7 mW. Proposed transmitter is designed for output power 4.1V. OOK receiver consists of an OOK demodulator, powered by rectified and regulated 5V p-p RF signal across the receiver coil. The supply voltage of proposed voltage regulator is 5 V with 9mV/V line regulation of. All circuits proposed in this paper were designed and simulated using Cadence in 0.18 um CMOS process.

3 citations

Proceedings ArticleDOI
01 Oct 2019
TL;DR: The goal of the study is to propose a new architecture for the power multiplexer without incurring significant efficiency degradation or cost is a tricky challenge and a control method of charging and discharging lithium-ion battery to prolong its lifetime.
Abstract: This work describes the design and simulation of a dual power source switching control to Li-Ion battery charger for medical power system applications. The proposed circuit consist of two sections. First section is a dual power source switching control used to switching between the main power and the backup battery power and a Li-Ion battery charger used to control the charging and discharging li-Ion battery. The goal of the study is to propose a new architecture for the power multiplexer without incurring significant efficiency degradation or cost is a tricky challenge and a control method of charging and discharging lithium-ion battery to prolong its lifetime.

1 citations

Proceedings ArticleDOI
01 Oct 2019
TL;DR: In this article, a low power temperature sensor for monitoring the temperature in a battery management system using MOS transistors is presented. But, the proposed sensor does not use any bipolar transistor (BJT) and instead, it is designed using Mos transistors, which operate in weak inversion region.
Abstract: This paper presents a compact and low power temperature sensor for monitoring the temperature in a Lithium-ion battery management system. The proposed sensor does not use any bipolar transistor (BJT); instead, it is designed using MOS transistors, which operate in weak inversion region. The principle is based on the temperature – voltage conversion. This voltage is a linear function of the temperature. The sensor is designed using CMOS technology for a temperature range of 0°C to 120°C, with a sensitivity of 1.08 mV/°C and uses a 1V power of supply. The circuit is simulated in Cadence tool using TSMC 180nm library.

1 citations

Journal ArticleDOI
TL;DR: A new power generating circuit for passive ultra high frequency (UHF) RFID tag that consists of a RF limiter, a high power efficiency and high sensitivity full wave radio frequency (RF) wave rectifier and a low-power regulator with NMOS diodes work like a DC-limiter.
Abstract: In this paper, we propose a new power generating circuit for passive ultra high frequency (UHF) RFID tag. The proposed power generating circuit consists of a RF limiter, a high power efficiency and high sensitivity full wave radio frequency (RF) wave rectifier and a low-power regulator with NMOS diodes work like a DC-limiter. The design method proposed in this study use one low drop out (LDO) regulator to provide tow output stable supply voltages vdd1 of value 1V for the digital section supply, and vdd2 of value 0.5V for the analog front-end section power supply. The proposed power generating circuit is optimized in terms of power consumption of RFID tag system to have a high operating range under conditions of 50 Ohm antenna, -24 dBm input RF power, 900MHz and 1 M DC, with low power dissipation and 29.15% large power conversion efficiency. The power generating circuit was designed, simulated and layouted in Cadence using TSMC 180 nm technology. The final design occupies approximately 0.25mm 2 .

1 citations

Book ChapterDOI
29 Jan 2021
TL;DR: In this paper, a first-order CMOS Bandgap reference using an operational amplifier with negative feedback to improve the power supply rejection ratio (PSRR) and reduce the temperature coefficient (TC).
Abstract: This article proposes the implementation and design of a first-order CMOS Bandgap reference using an operational amplifier with negative feedback to improve the power supply rejection ratio (PSRR) and reduce the temperature coefficient (TC). The circuit is designed in 180 nm CMOS process technology and provides a reference output voltage of 1.2 V over an extended temperature range from −40 °C to 120 °C with a measured temperature coefficient of 54 ppm/°C. The BGR chip uses a 1.8 V supply.

Cited by
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Journal ArticleDOI
31 Jan 2021-Sensors
TL;DR: A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60-700 K, currently the widest range reported.
Abstract: A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported The structure’s layout places the two identical diodes in close, symmetrical proximity A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain High sensitivity, upwards of 232 mV/K, is obtained, with satisfactory linearity (R2 reaching 9980%) for the CTAT sensor, even down to 60 K The PTAT differential version boasts increased linearity, up to 9995% The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 1491 mV/K, without influencing linearity

10 citations

Proceedings ArticleDOI
18 Jun 2019
TL;DR: A high performance fully integrated 900 MHz analog front end for UHF RFID tag EPC C1 G2 standard protocol is presented and the minimizing of the input voltage of the converter is proposed.
Abstract: In this paper, a high performance fully integrated 900 MHz analog front end for UHF RFID tag EPC C1 G2 standard protocol is presented. The proposed analog front end consists of a voltage regulation which consists of an RF to DC converter, voltage regulator circuit which regulated the DC voltage to prefer value (0.5V), ASK modulator/demodulator, a clock generator and a power on reset circuit. To minimize the power consumption of RFID transponder we propose the minimizing of the input voltage of the converter. Proposed regulator is designed under following conditions: RF frequency’s 900 MHz, 50 Ω antenna, a sensitivity of -24 dBm and a maximum power consumption of 1 µW. At 0.5 V proposed demodulator can demodulate the minimum input power -24 dBm for a modulation index of 37–100 % with 160 kbps data rates and consumes only12.74 nW. The power consumption and layout of the analog front end proposed in this work are about 1 uW and only 79 μm × 67 μm respectively. The simulation results dawn in 0.18 μm CMOS technology confirm the performance of the proposed analog front-end.

2 citations

Journal ArticleDOI
TL;DR: A wideband frequency shift keying (FSK) transmitter, which is a class E power amplifier that switches between two load networks that make the PA tuned correctly at tow input clock frequencies, is presented.
Abstract: The external unit of small telemetry system for animals uses inductive link to transmit both data and power to a small implant. In this work, firstly, we have presented a wideband frequency shift keying (FSK) transmitter, which is a class E power amplifier (PA) switches between two load networks that make the PA tuned correctly at tow input clock frequencies. Carrier frequencies used for data modulation are 5MHz/10MHz, the data rate of the proposed link is 2.5 Mbps. On the other hand, the analog circuits of the internal unit are designed in this paper. Internal unit has a demodulator circuit to derive directly a frequency clock from the FSK carrier and to sample the binary data stream. It also has a low power generator circuit to generate the supply voltage to the other blocks. The low power generator is composed of a high efficiency, low power rectifier, and a low power voltage regulator. To minimize the quiescent current of the regulator, we propose a control section which is a two-stage error amplifier to control the gate voltage of the PMOS transistors used in the differential pair of the voltage regulator and thus stabilize the direct current (DC) level at its output signal (Vreg). The output voltage of the proposed generator circuit is regulated at 1V, the quiescent current simulated is about 9.9μA and the line regulation performance is only 8mV/V. All circuits proposed in this paper were designed and simulated using Cadence in 180 nm CMOS technology.

1 citations

Proceedings ArticleDOI
15 Sep 2022
TL;DR: In this article , a switch case statement method is used to avoid repeated statements in a system considering that the DC automatic switch system in this study uses four different sources namely energy sources designed for renewable energy (hybrid) as a priority supply.
Abstract: Conventional energy consumption has increased every year, especially in the electricity sector, but is not balanced with available conventional electrical energy sources. So that the proposed effort related to these problems is the use of renewable energy, but in the implementation of the transition from conventional energy to renewable energy it still takes several processes and costs quite a lot. The proposal made by the author offers a solution in the form of an automatic switch that combines several renewable energy sources of electricity as a top priority and makes conventional electrical energy a backup source. The contribution of this research is to reduce the level of conventional energy consumption, in this study conventional energy is converted into a DC system. The goal is for the system to gradually enter a renewable energy DC system. The advantage of this research is that the system used in the automatic switch can be updated to adjust the load so that in the future the automatic switch system can work without using conventional energy. In this study using the switch case statement method, the advantage of this method is that it can avoid repeated statements in a system considering that the DC automatic switch system in this study uses four different sources namely energy sources designed for renewable energy (hybrid) as a priority supply. 1, battery 1 (from hybrid system) as priority supply 2, conventional energy(PLN) as priority supply 3, and battery 2 (from conventional energy) as priority supply 4. In testing the automatic switch conditions as many as 43 of the four sources there were 941 events to select the voltage a source that meets the criteria of 12 volts to supply the load and for the same voltage is passed according to the voltage priority and for a voltage of 10 volts is passed in the system. And on testing to load 40 watt a constant working voltage and current. in the range of 12–14 volts and a current of 2.8-3.4 A.
Journal ArticleDOI
01 Sep 2022
TL;DR: The system achieves good range but falls short in efficiency to charge a battery, charging of battery takes longer time than regular charging time and further research and extensive exploration can bring this technology from theory to practice.
Abstract: The system is novel approach to combine wireless power transmission system (WPT) and automated guided vehicle (AGV). The wireless power transfer for charging the mobile robot is implemented using inductive coupling method. The system setup consists of transmitter coils whose switching action is controlled through transistors, receiver coil connected to full ridge rectifier and mobile robot. The track consists of number of transmitter coil which transmits power in form of electromagnetic waves. The receivers in the robot, which receives these waves and converts it back to electric power to charge the battery. The robot tracks its target destination based on the user command from the smart phone through Bluetooth. Very few theoretical researches are available on this field. A prototype was developed and tested based on the researches. The system achieves good range but falls short in efficiency to charge a battery, charging of battery takes longer time than regular charging time. Further research and extensive exploration can bring this technology from theory to practice.