Fast-settling CMOS operational amplifiers with negative conductance voltage gain enhancement
نویسندگان
چکیده
Negative conductance voltage gain enhancement techniques which substantially increases the dc gain of an operational amplifier without degrading speed are discussed. Three fully differential CMOS op amps using the negative conductance gain enhancement technique are presented. Simulations show that for a 0.35um CMOS technology with a power supply of 3V, a dc gain of more than 94dB is achievable with the proposed amplifiers. Settling measurements with a feedback factor of β = 1⁄2 show fast settling behavior and a settling accuracy of better than 0.1% for a 1.2V input step.
منابع مشابه
CMOS Active-Cascode Gain Stage
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...
متن کاملA Negative Conductance Voltage Gain Enhancement Technique for Low Voltage High Speed CMOS Op Amp Design
A new circuit technique for voltage gain enhancement in CMOS op amp design suitable for low voltage and high speed operation is presented in this paper. A negative conductance is used to cancel the positive output conductance of an amplifier thereby reducing the total equivalent output conductance and increasing the voltage gain of the amplifier. The negative conductance is derived from the out...
متن کاملDesign a Low Voltage- Low Offset Class AB Op-Amp
A new design approach for three-stage operational amplifiers (op-amps) is proposed. It allows to actually implement a symmetrical push-pull class-AB amplifier output stage for wellestablished three-stage amplifiers using a feedforward transconductance stage. Compared with the conventional design practice, the proposed approach leads to a significant improvement of the symmetry between the posit...
متن کاملHigh Gain Amplifier with Enhanced Cascoded Compensation
A two-stage CMOS operational amplifier with both, gain-boosting and indirect current feedback frequency compensation performed by means of regulated cascode amplifiers, is presented. By using quasi-floating-gate transistors (QFGT) the supply requirements, the number of capacitors and the size of the compensation capacitors respect to other Miller schemes are reduced. A prototype was fabricated ...
متن کاملA high-swing 2-V CMOS operational amplifier with replica-amp gain enhancement
Abstrtict— A general gain-enhancement technique for operational amplifiers using a replica amplifier is described. Unlike conventional techniques such as cascoding, which increases the gain by increasing the output resistance, the replica-amp technique increases the gain by matching the main and the replica amps. Among the advantages of the replica-amp technique are low supply, high swing, and ...
متن کامل