The authors show how continuous-time active-RC filters can be implemented in CMOS by replacing all resistors by MOSFETs operating in the linear region. As an example, a 24MHz activeMOSFET-C single-amplifier biquadratic lowpass filter with a pole-Q of 3 implemented in a 0.6μm CMOS process is discussed. By comparing measurements of a test chip, simulations and calculations, the following conclusi...

There is a need to explore circuit designs in new emerging technologies for their rapid commercialization to extend Moore’s law beyond 22 nm technology node. Carbon nanotube based transistor (CNFET) has significant potential to replace CMOS in the future due to its better electrostatics and higher mobility. This paper presents a complete optimal design of an inverting amplifier in CMOS, CNFET a...

A fully integrated CMOS wideband Low Noise Amplifier (LNA) operating over 2.3–7 GHz is designed and fabricated using a 0.18 μm CMOS process. The proposed structure is a common sourcecommon source (CS-CS) cascode amplifier with a coupling capacitor. It realizes both low voltage drop at load resistor (Rload) and high gain over 2.3–7 GHz with simultaneous noise and input matching and low power con...

This paper presents a CMOS voltage controlled ring oscillator (VCO) with temperature compensation circuit suitable for low-cost and low-power MEMS gas sensor. This compensated ring oscillator is dedicated to Chopper Stabilized CMOS Amplifier (CHS-A). To operate at low frequency, a control voltage generated by a CMOS bandgap reference (BGR) is described and the measurement results of the fabrica...

A new OTA-based logarithmic-control variable gain current amplifier (LCCA) is presented. It consists of two Operational Transconductance Amplifier (OTA) and two PMOS transistors biased in weak inversion region. The circuit operates from 0.6V DC power supply and consumes 0.6 μW. The linear-dB controllable output range is 43 dB with maximum error less than 0.5dB. The functionality of the proposed...

A CMOS Variable Gain Amplifier (VGA) is proposed for high frequency and low power broadband communication systems, such as Ultra-Wide Band (UWB) receiver. The VGA consists of a P/NMOS complimentary differential-pair with source degeneration, a high-swing current mirror stage with capacitive feedforward frequency compensation, and resistive load. Description Based on an OFDM UWB receiver system’...

A new method based on adaptive GA(genetic algorithm) for optimizing the parameters of CMOS operational amplifier is presented in this paper. The synthesis of the Op-amp (operational amplifier) can be translated into multiple-objective optimization task, in which a large number of specifications have to be taken into account. Such as DC-gain, bandwidth of unity gain, phase-margin, power, noise a...

This paper presents a column-parallel continuous-time sigma delta (CTSD) ADC for mega-pixel resolution CMOS image sensor (CIS). The sigma delta modulator is implemented with a 2nd order resistor/capacitor-based loop filter. The first integrator uses a conventional operational transconductance amplifier (OTA), for the concern of a high power noise rejection. The second integrator is realized wit...

A high-swing, high-performance CMOS telescopic operational amplifier is described. The high swing of the op-amp is achieved by employing the tail and current source transistors in the deep linear region. The resulting degradation in differential gain, common-mode rejection ratio (CMRR), and other amplifier characteristics are compensated by applying regulatedcascode differential gain enhancemen...

The drive for cost reduction has led to the use of CMOS technology in the implementation of highly integrated radios. This paper presents a single-chip 5-GHz fully integrated direct conversion transceiver for IEEE 802.11a WLAN systems, manufactured in 0.18m CMOS. The IC features an innovative system architecture which takes advantage of the computing resources of the digital companion chip in o...