Solutions for CMOS current amplifiers with high-drive output stages

Abstract

Design guidelines for CMOS current amplifiers with a high-drive capability are discussed in detail, paying special attention to the implementation of output stages with improved linearity performance. As a design example, two different current amplifiers were realized in a 1.2-m process and experimentally tested. Both circuits used a 5-V power supply and dissipated 5.5 and 4 mW, respectively. The open-loop gain was found to be 90 and 100 dB and the gain-bandwidth product was 8 and 10 MHz. The two amplifiers provide bipolar output currents as high as 15 and 7 mA, with a maximum total harmonic distortion of around 54 dB, using a quiescent current in the output branches of only 200 A.Index Terms-CMOS analog integrated circuits, current mode, integrated circuit design, operational amplifiers, power amplifiers.

First-Order All-Pass Filter Canonical in the Number of Resistors and Capacitors Employing a Single DDCC

“…To implement the DDCC+, various circuit techniques, such as the one shown in Figure 3, can be used. The input stage of the given CMOS DDCC+ is based on a rail-to-rail differential transconductance section [21] to achieve a wide swing range between Y-ports and X-port voltages. The proposed filter is affected by the load impedance, so the output stage of the CMOS DDCC+ is composed from the CMOS structure proposed by [33] to produce a high output impedance.…”

CMOS class-AB tunable voltage-feedback current operational amplifier

“…The topology is based on the well-known wide-swing cascode NMOS current mirror. Cascode output stage is used because even though other output stages are capable of achieving higher output resistance and linearity [3], [12] they are less power efficient.…”

“…Accurate analog signal processing is obtained through high-gain operational amplifiers used in closed loop. High-performance implementations of the CM equivalents of the conventional opamp and the current-feedback opamp [2], (named Current Operational Amplifier, COA [3] and Voltage Feedback Current Operational Amplifier, VFCOA [4]- [6], respectively) are therefore required. The COA, being the CM counterpart of VOAs, is still limited by the constant gainbandwidth product [7].…”

Design of High-Frequency Filters Working in the Pure Current Mode with CMI

“…Also, a better bandwidth can be obtained when the circuit works in the current mode. These are some of the reasons leading to the present increase in frequency filters working in the current mode [1] to [6].…”