Design Of Low Voltage Low Power Operational Amplifier Cells

Design of Low-Voltage, Low-Power Operational Amplifier Cells

Design of Low-Voltage, Low-Power CMOS Operational Amplifier Cells describes the theory and design of the circuit elements that are required to realize a low-voltage, low-power operational amplifier. These elements include constant-gm rail-to-rail input stages, class-AB rail-to-rail output stages and frequency compensation methods. Several examples of each of these circuit elements are investigated. Furthermore, the book illustrates several silicon realizations, giving their measurement results. The text focuses on compact low-voltage low-power operational amplifiers with good performance. Six simple high-performance class-AB amplifiers are realized using a very compact topology making them particularly suitable for use as VLSI library cells. All of the designs can use a supply voltage as low as 3V. One of the amplifier designs dissipates only 50μW with a unity gain frequency of 1.5 MHz. A second set of amplifiers run on a supply voltage slightly above 1V. The amplifiers combine a low power consumption with a gain of 120 dB. In addition, the design of three fully differential operational amplifiers is addressed. Design of Low-Voltage, Low-Power CMOS Operational Amplifier Cells is intended for professional designers of analog circuits. It is also suitable for use as a text book for an advanced course in CMOS operational amplifier design.

Design of Low-voltage Low-power CMOS Operational Amplifier Cells

The Design of Low-Voltage, Low-Power Sigma-Delta Modulators

Oversampling techniques based on sigma-delta modulation are widely used to implement the analog/digital interfaces in CMOS VLSI technologies. This approach is relatively insensitive to imperfections in the manufacturing process and offers numerous advantages for the realization of high-resolution analog-to-digital (A/D) converters in the low-voltage environment that is increasingly demanded by advanced VLSI technologies and by portable electronic systems. In The Design of Low-Voltage, Low-Power Sigma-Delta Modulators, an analysis of power dissipation in sigma-delta modulators is presented, and a low-voltage implementation of a digital-audio performance A/D converter based on the results of this analysis is described. Although significant power savings can typically be achieved in digital circuits by reducing the power supply voltage, the power dissipation in analog circuits actually tends to increase with decreasing supply voltages. Oversampling architectures are a potentially power-efficient means of implementing high-resolution A/D converters because they reduce the number and complexity of the analog circuits in comparison with Nyquist-rate converters. In fact, it is shown that the power dissipation of a sigma-delta modulator can approach that of a single integrator with the resolution and bandwidth required for a given application. In this research the influence of various parameters on the power dissipation of the modulator has been evaluated and strategies for the design of a power-efficient implementation have been identified. The Design of Low-Voltage, Low-Power Sigma-Delta Modulators begins with an overview of A/D conversion, emphasizing sigma-delta modulators. It includes a detailed analysis of noise in sigma-delta modulators, analyzes power dissipation in integrator circuits, and addresses practical issues in the circuit design and testing of a high-resolution modulator. The Design of Low-Voltage, Low-Power Sigma-Delta Modulators will be of interest to practicing engineers and researchers in the areas of mixed-signal and analog integrated circuit design.