A versatile building block: the CMOS differential difference amplifier
TL;DR: An extension of the op-amp concept featuring two differential inputs, in a closed-loop environment this circuit forces two floating voltages to the same value, and thus has many interesting applications in the analog circuit domain.
Abstract: An extension of the op-amp concept featuring two differential inputs is presented. In a closed-loop environment this circuit forces two floating voltages to the same value, and thus has many interesting applications in the analog circuit domain. A description of such a circuit, its nonidealities, and restrictions are given. A monolithic integration of this differential difference amplifier is implemented in a double-poly CMOS technology, its measured characteristics are described. Many applications of this circuit, including a voltage comparator with floating inputs, a voltage inverter without resistors, and an instrumentation amplifier with only two external gain determining resistors, are discussed.
Citations
More filters
Journal Article•
TL;DR: An analysis of the state-of-the-art of active elements for analog signal processing is presented which support - in contrast to the conven tional operational amplifiers - not only the voltage-mode but also the current- and mixed-mode operations.
Abstract: In the paper, an analysis of the state-of-the-art of active elements for analog signal processing is presented which support - in contrast to the conven tional operational amplifiers - not only the voltage-mode but also the current- and mixed-mode operations. Several pro blems are addressed which are associated with the utiliza tion of these elements in linear applications, particularly in frequency filters. A methodology is proposed which generates a number of fundamentally new active elem ents with their potential utilization in various areas o f signal processing.
650 citations
Cites background from "A versatile building block: the CMO..."
...The principle of the DDA was published for the firs t time by Säckinger in 1987 [35]....
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TL;DR: In this paper, a simple cascode with the gate voltage of the cascode transistor being controlled by a feedback amplifier called a regulated cascode is presented, where the minimum output voltage is lower by 30 to 60% while the output conductance and the feedback capacitance are lower by about 100 times.
Abstract: A simple cascode with the gate voltage of the cascode transistor being controlled by a feedback amplifier called a regulated cascode is presented. In comparison to the standard cascode circuit, the minimum output voltage is lower by about 30 to 60% while the output conductance and the feedback capacitance are lower by about 100 times. An analytical large-signal, small-signal, and noise analysis is carried out. Some applications like current mirrors and voltage amplifiers are discussed. Experimental results confirming the theory are presented. >
553 citations
Book•
11 Mar 2005
TL;DR: This paper presents a meta-modelling system that automates the very labor-intensive and therefore time-heavy and therefore expensive and expensive process of manually winding and disconnecting receiver and modulator systems.
Abstract: Preface. 1. Introduction. 2. Optical Fiber. 3. Photodetectors. 4. Receiver Fundamentals. 5. Transimpledance Amplifiers. 6. Main Amplifiers. 7. Optical Transmitters. 8. Laser and Modulator Drivers. Appendix A: Eye Diagrams. Appendix B: Differential Circuits. Appendix C: S Parameters. Appendix D: Transistors and Technologies. Appendix E: Answers to the Problems. Appendix F: Notation. Appendix G: Symbols. Appendix H: Acronyms. References. Index.
415 citations
TL;DR: A new digital programmable CMOS analog front-end (AFE) IC for measuring electroencephalograph or electrocardiogram signals in a portable instrumentation design approach is presented and measurement results have shown that the proposed biomedical AFE IC achieves a maximum stable ac gain.
Abstract: A new digital programmable CMOS analog front-end (AFE) IC for measuring electroencephalograph or electrocardiogram signals in a portable instrumentation design approach is presented. This includes a new high-performance rail-to-rail instrumentation amplifier (IA) dedicated to the low-power AFE IC. The measurement results have shown that the proposed biomedical AFE IC, with a die size of 4.81 mm/sup 2/, achieves a maximum stable ac gain of 10 000 V/V, input-referred noise of 0.86 /spl mu/ V/sub rms/ (0.3 Hz-150 Hz), common-mode rejection ratio of at least 115 dB (0-1 kHz), input-referred dc offset of less than 60 /spl mu/V, input common mode range from -1.5 V to 1.3 V, and current drain of 485 /spl mu/A (excluding the power dissipation of external clock oscillator) at a /spl plusmn/1.5-V supply using a standard 0.5-/spl mu/m CMOS process technology.
219 citations
Cites background from "A versatile building block: the CMO..."
...Another promising approach is the differential difference amplifier (DDA)-based noninverting IA [16], [17], which has...
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TL;DR: In this paper, two new types of second generation current conveyor (CCII) are introduced and the properties of the nullor and mirror elements are used to relate the different devices in the ideal case as well as to define the adjoint network for each building block.
Abstract: The concept of voltage mirror is introduced and used, together with the current mirror, to ideally represent the current and voltage inverting properties of some analogue building blocks. The properties of the nullor and mirror elements are used to relate the different devices in the ideal case as well as to define the adjoint network for each building block. Two new types of second generation current conveyor (CCII) are introduced. One is the adjoint of the CCII+ and is named the inverting second generation current conveyor ‘negative’ (ICCII–); the other is the ICCII+. CMOS realizations of the ICCII– are presented and new ICCII– based current mode circuits are obtained by applying a voltage-to-current-mode transformation to the CCII+ based circuits.
219 citations
References
More filters
TL;DR: In this paper, an overview of current design techniques for operational amplifiers implemented in CMOS and NMOS technology at a tutorial level is presented, focusing on CMOS amplifiers because of their more widespread use.
Abstract: Presents an overview of current design techniques for operational amplifiers implemented in CMOS and NMOS technology at a tutorial level. Primary emphasis is placed on CMOS amplifiers because of their more widespread use. Factors affecting voltage gain, input noise, offsets, common mode and power supply rejection, power dissipation, and transient response are considered for the traditional bipolar-derived two-stage architecture. Alternative circuit approaches for optimization of particular performance aspects are summarized, and examples are given.
493 citations
TL;DR: In this paper, the design of voltage- or current-controllable linear transconductance elements needed for the continuous-time CMOS active filters is explored in detail, and circuit configurations, techniques of achieving linearity, and temperature compensation using the controlling variable are outlined.
Abstract: This paper explores in detail the possible approaches to. the design of voltage- or current-controllable linear transconductance elements needed for the design of continuous-time CMOS active filters. The focus of the paper is on circuit configurations, techniques of achieving linearity, and temperature compensation using the controlling variable. Circuit techniques for obtaining small transductance values are outlined. Simulation results are presented.
184 citations
TL;DR: The linearized transconductance multiplier (LTM) has rapidly gained acceptance as the preferred approach to the realization of monolithic analog multipliers, and its simplicity has commended it for use in low-cost modular designs.
Abstract: Since its conception in 1967, the linearized transconductance multiplier (LTM) has rapidly gained acceptance as the preferred approach to the realization of monolithic analog multipliers, and its simplicity has commended it for use in low-cost modular designs. Accuracies of these units have been limited to about 0.5 to 2 percent, and drift and noise performance have generally been worse than that possible using the dominant alternative technique of pulse-width-height modulation. This paper shows that when careful attention is given to all the sources of error it is possible to attain a five-fold improvement in accuracy and corresponding reductions in the drift and noise levels. Odd-order nonlinearities can be reduced to negligible magnitudes by the use of active feedback, by substituting the usual resistive-bridge feedback path by an amplifier identical to that used as the input stages.
148 citations
TL;DR: In this paper, a CMOS switched capacitor instrumentation amplifier is presented, where offset is reduced by an auto-zero technique and effects due to charge injection are attenuated by a special amplifier configuration.
Abstract: A CMOS switched capacitor instrumentation amplifier is presented. Offset is reduced by an auto-zero technique and effects due to charge injection are attenuated by a special amplifier configuration. The circuit which is realized in a 4-/spl mu/m double poly process has an offset (/spl tau/) of 370 /spl mu/V, an rms input referred integrated noise (0.5 -f/sub c//2) of 79 /spl mu/V, and consumes only 21 /spl mu/W (f/sub c/ = 8 kHz, V/sub DD/ = 3 V).
131 citations
Proceedings Article•
01 Jan 1984TL;DR: In this paper, a CMOS switched capacitor instrumentation amplifier is presented, where offset is reduced by an auto-correlation technique and effects due to charge injection are attenuated by a special amplifier configuration.
Abstract: A CMOS switched capacitor instrumentation amplifier is presented. Offset is reduced by an auto-correlation technique and effects due to charge injection are attenuated by a special amplifier configuration. The circuit which is realized in a 4 ?m double poly process has a typical offset (?) of 370 ?V, an RMS input referred integrated noise (0-f c /2) of 79 ?V and consumes only 21 ?W (f c = 8 kHz, V DD = 3 V).
117 citations