Many existing results on the analysis of OFDM systems are based on an analog representation. The actual implementation of OFDM transmitters typically consists of a discrete DFT matrix and a digital-to-analog (DAC) converter. In this paper, we show that the analog representation admits the implementation of a DFT matrix followed by a DAC converter only in special cases. Necessary and sufficient ...

A new Successive-Approximation ADC (Analog-toDigital Converter) was designed which not only consumes little power, but also requires a small chip area. To achieve those goals, both comparator and internal DAC (Digital-to-Analog Converter) have been improved. The ADC was designed in a 1.2 μm CMOS double-poly double-metal n-well process. It performs 10-bit conversion with 67 dB SFDR. Power consum...

I mprovements in the speed and resolution of both digital to ana-log converters (DACs) and analog to digital converters (ADCs) have resulted in a continual push to move more func-tionality into the digital signal processing arena. RF and analog signal processing methodologies such as filtering and frequency translation are being handled increasingly in the digital domain, where near-ideal filte...

Microcontrollers are emerging into new applications like smart phones, audio accessories, video gaming peripherals and advanced medical devices, providing highperformance, reliability and low-power consumption for end users. In this paper the design of a microcontroller-based hearing aid device is provided, by which power consumption and hardware area are reduced. The proposed digital hearing a...

A 6-bit weighted-current-sink video digital-to-analog converter (DAC) with 10-90 percent rise/fall time of 4 ns, integrated with a double-metal 3pm CMOS technology, is described. Current-source matching, glitch reduction, and differential switch driving aspects are considered. A new circuit solution and a nonconventional layout technique yield a high conversion rate with a standard CMOS technol...

To build a digital to analog converter, that only receives digital signal that can only receives digital signal and produces only analog signal. A converter in which digital input signals are changed to essentially proportional analog signals. Abbreviated DAC a device for converting information in the forms of combination of discrete(usually binary) states or signal to information in the form o...

A high-conversion-rate high-resolution oversampling digital-to-analog converter (DAC) for direct digital modulation is addressed in this paper. A new type of switching scheme, called differential-quad switching, is presented. To verify the feasibility of this scheme, essential parts with some auxiliary circuitry for interfacing were fabricated in a 0.8m CMOS technology. Measured results show th...

For both the electrical stimulation and recording of cultured neurons, the CMOS-based microelectrode arrays (MEAs) are one of the most promising electronic devices used nowadays. To ensure a robust transmission of the information between the chip and external devices, the MEA chip requires integrated analog-to-digital converters (ADCs). Moreover, the presence of a large number of read-out chann...

A second-order audio analog-to-digital converter (ADC) modulator using a second-order 33-level tree-structured mismatch-shaping digital-to-analog converter (DAC) is presented. Key logic simplifications in the design of the mismatch-shaping DAC encoder are shown which yield the lowest complexity second-order mismatch-shaping DAC known to the authors. The phenomenon of signal-dependent DAC noise ...