Cmos Current Amplifiers

by Palmisano, Giuseppe; Palumbo, Gaetano; Pennisi, Salvatore

• ISBN13: 9780792384694
• ISBN10: 0792384695
• Format: Hardcover
• Copyright: 1999-02-01
• Publisher: Kluwer Academic Pub

Summary

CMOS Current Amplifiers presents design strategies for high performance current amplifiers based on CMOS technology. After an introduction to various architectures of operational amplifiers, the operating principles of the current amplifier are outlined. This book provides the reader with simple and compact design equations for use in a pencil and paper design and the following simulation step. Chapter 1 introduces the general aspects of current amplifiers. After a preliminary classification of operational amplifiers, ideal blocks and models are discussed for different architectures and a first high-level comparison is made between traditional amplifiers and current amplifiers. Analysis and examples of basic circuits, as well as signal processing applications involving current amplifiers, are also given. Non-idealities and second- order effects causing limitations in performance are then discussed and evaluated. Chapter 2 focuses on low-drive current amplifiers. Several design examples for current conveyors and class A current amplifiers are discussed in detail and design equations are presented for the main performance parameters, which allows a good trade-off between requirements. High-performance solutions for high bandwidth and low voltage capability are also considered, and, finally, current comparators with progressively enhanced performance are reported and analyzed critically. Chapter 3 deals with current amplifiers for off-chip loads. Several class AB current-mode output stages are discussed and design strategies which improve performance are presented. A detailed analysis of non-ideal effect is carried out with particular emphasis on linearity. Design examples are given and circuit arrangements for further developments are included. CMOS Current Amplifiers serves as an excellent reference for researchers and professionals of analog IC design, and may also be used as an advanced text on current amplifiers.

Table of Contents

Acknowledgments	ix
Abbreviations	xi
Preface	xiii
Operational Amplifiers	1	(44)
The Operational Amplifier Set	2	(7)
Op-Amp Configurations	9	(5)
The Gain Bandwidth Trade-Off	14	(3)
Current Amplifiers Using Voltage Op-Amps	17	(4)
Signal Processing With Current Op-Amps	21	(2)
Towards a True COA	23	(3)
Performance Parameters of Current Amplifiers	26	(19)
Further Comments	33	(7)
References	40	(5)
Low-Drive Current Amplifiers	45	(62)
Input Stages	48	(21)
The CCII	48	(3)
Class A Input Stages	51	(12)
Class AB Input Stages	63	(6)
Class `A' Current Output Stages	69	(5)
Output Stages for COAs	70	(4)
Output Stages for VFCOAs	74	(1)
Design Examples	74	(10)
COA Configurations	75	(4)
VFCOA Configurations	79	(5)
Current Comparators	84	(23)
High-Speed Approaches	85	(3)
Design Control Considerations	88	(1)
Offset Compensation	89	(8)
Design Examples	97	(5)
References	102	(5)
High-Drive Curent Amplifiers	107	(52)
Class AB Current Output Stages	108	(5)
Configurations	111	(2)
Harmonic Distortion Due to Channel-Length Modulation	113	(8)
COS Based On Regular Cascoded Mirrors	113	(2)
COS Based On Cascoded Mirrors With Dynamic Matching	115	(1)
COS Based On Cascoded Mirrors With Improved Dynamic Matching	116	(2)
COS based on Active-Gain Enhanced Cascoded Mirrors	118	(1)
Simulation Results	119	(2)
Harmonic Distortion Due to Mismatches	121	(4)
Threshold Voltage Mismatches	121	(3)
Transconductance Parameter Mismatches	124	(1)
Design Examples	125	(21)
A VFCOA Configuration	125	(11)
COA Configurations	136	(10)
A Versatile Fully Differential COA	146	(4)
Measurement Strategies	150	(3)