In low voltage low power CMOS systems both the high input offset and noise voltages of MOSFETs and also the moderate gain of op amps limit the accuracy of analog circuits. In this paper we present a new high-accuracy instrumentation amplifier; this circuit topology is the first ever reported "non-autozero" instrumentation amplifier which allows to compensate, beside the input offset and noise v...

An s-domain analysis of the full dynamics of the pole-zero pair (frequency doublet) associated with the broadly used CMOS active-cascode gain-enhancement technique is presented. Quantitative results show that three scenarios can arise for the settling behavior of a closed-loop active-cascode operational amplifier depending on the relative locations of the unity-gain frequencies of the auxiliary...

ABSTRACT: In this paper, the design of lowpower secondorder switched – capacitor bandpass filter is presented in 0.18μm CMOS technology. Instead of two operational amplifiers in conventional structures only one operational amplifier is used to significantly reduce power consumption and chip area. Quality factor and maximum gain can be simply tuned by employing lowthreshold NMOS transistors as t...

This application report introduces the concept of electromagnetic interference rejection ratio (EMIRR IN+) as a measure of the immunity of an operational amplifier to responding to electromagnetic interference (EMI). Texas Instruments has developed the ability to accurately measure and quantify the immunity of an operational amplifier over a broad frequency spectrum extending from 10 MHz to 6 G...

The need for high bandwidth operational amplifiers (op amp) exists for numerous applications. This need requires research in the area of op amp bandwidth extension. The exploited method in this thesis uses a class of compensation called Indirect Feedback Frequency Compensation in which the compensation current is fed back indirectly from the output to an internal high impedance node, to extend ...

This paper presents a new method to improve the GBW (gain-bandwidth product) on negative feedback amplifiers. The proposed method is based on the introduction of time delay elements in the feedback loop, which can be exploited to retrieve significant bandwidth enhancements. This delayed feedback concept is analyzed, and considerations are presented for first order amplifiers, based on theoretic...

Recently, we developed a low power consumption and small total capacitance switched-capacitor filter using a single operational amplifier. It is called a semi-parallel cyclic type (SPCT) filter, in which each capacitance is in proportion to the square root of a transfer function coefficient value. In this paper, we propose the SPCT filter using a single unity gain buffer (UGB). It will be refer...

This paper proposes and studies the effects of a dual-stage compensation technique for achieving greater than 100 kHz crossover frequency of a single pole system converting from 48 V to 1.2 V. By placing a separate non-inverting gain stage after the error amplifier, the necessary gain-bandwidth of the op amp can be significantly reduced allowing for high crossover frequency and good transient r...

This paper describes a method of extending the signal frequency bandwidth while increasing the stability of a CMOS transimpedance amplifier (TIA). The TIA consists of three inverting amplifiers in a series, and a high-pass filter plus a non-inverting amplifier that are connected to the last two inverting amplifiers stated above in parallel. The TIA is fabricated using a 0.35 μm CMOS process and...

This paper proposes new admittance matrix models to approach the behavior of fully-differential Operational Transresistance Amplifiers (OTRAs) and Current Operational Amplifiers (COAs). The infinity-variables method is used in order to derive the new generalized models. As a consequence, standard nodal analysis being improved to compute fully-symbolic small-signal characteristics of fullydiffer...