Hassan O. Elwan

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In this paper, a novel fully differential second-generation current conveyor (FDCCII) is presented. The proposed block is useful in mixed-mode applications where fully differential signal processing is required. Furthermore, the FDCCII can be used to realize MOSFET-C filters. The circuit has a bandwidth of about 10 MHz under heavy capacitive loads and can(More)
In this paper, a differential-ramp based variable gain amplifier (VGA) technique is introduced. Using the proposed technique, digitally programmable gain amplifiers (PGAs) can be converted to analog controlled, dB-linear VGAs with minimum impact on noise and linearity. This provides an efficient way of realizing an analog controlled VGA for OFDM based(More)
In this paper, a new technique for realizing area-efficient, low-noise filters is introduced. The proposed filter topologies utilize noise shaping techniques to shift the noise of the passive and active filter components out of the passband of the filter. This is illustrated by implementing a programmable noise-shaped post-mixer gain-filtering circuit for a(More)
This paper presents a new CMOS current feedback operational amplifier (CFOA) with rail to rail swing capability at all terminals. The circuit operates as a class AB for lower power consumption. Besides operating at low supply voltages of 1.5 V, the proposed CFOA has a standby current of 200 A. The proposed CFOA circuit is thus a versatile building block for(More)
413 0.92 for circuit B, and 157 kHz and 2.09 for circuit C, respectively. Fig. 4(a) shows the responses for the highpass and lowpass functions of the three-input single-output filter. Its bandpass responses are shown in Fig. 4(b). All the results are in good agreement with the theoretical predictions. In the same way, the responses for the HSPICE simulation(More)
A two-stage differential-ramp based continuous-tuning IF VGA is introduced. The design has a bandwidth in excess of 100 MHz consuming 5-mA from a 1.2-V supply. The ramp generation circuit consumes additional 200 µA from a 2.5-V supply. Thanks to the multiple differential control ramps, 49-dB linear-in-dB continuous gain tuning range is achieved with(More)
In this paper, an integrated DC-DC (Buck) converter is presented. The Buck converter has two modes of operation. The continuous mode is used for heavy loads, and the pulse-skipping modulation (PSM) mode is used for light loads. To optimize the Buck converter efficiency in PSM mode, an ON-time control loop is utilized. Short-circuit and over-temperature(More)
In this paper, an integrated DC-DC (Buck) converter is presented. The Buck converter accepts input voltage in the range 2.7–5.5V while using 2.5V devices. A low drop-out (LDO) regulator is used to limit the maximum input voltage to the DCDC switches to protect it against overvoltage breakdown. 5MHz switching frequency is used to allow using smaller(More)