Miller Compensation Using Current Buffers in Fully Differential CMOS Two-Stage Operational Amplifiers

Author(s):  
P.J. Hurst ◽  
S.H. Lewis ◽  
J.P. Keane ◽  
F. Aram ◽  
K.C. Dyer
2008 ◽  
Vol 17 (01) ◽  
pp. 1-13 ◽  
Author(s):  
HAMED AMINZADEH ◽  
REZA LOTFI

Optimization of power consumption is one of the main design challenges in today's low-power high-speed analog integrated circuits. In this paper, two popular techniques to stabilize two-stage operational amplifiers, namely, Miller and cascode compensations are compared from power efficiency point of view. To accomplish this, cascode-compensated topologies are basically analyzed to derive the required equations for the comparison. In the analysis, a new method to take into account the effect of transfer function zeros is proposed. By assuming that the zeros' magnitudes are fairly nondominant, the method increases the accuracy of the analyses. The relationships show that for the same specifications, cascode compensation is more power-efficient than Miller compensation, especially for heavy capacitive loads. This has been confirmed by SPICE simulations.


Author(s):  
Furkan Barin ◽  
Ertan Zencir

In this paper, an ultra-wideband fully differential two-stage telescopic 65-nm CMOS op-amp is presented, which uses low-voltage design techniques such as level shifter circuits and low-voltage cascode current mirrors. The designed op-amp consists of two stages. While the telescopic first stage provides high speed and low swing, the second stage provides high gain and large swing. Common-mode feedback circuits (CMFB), which contain five transistors OTA and sensing resistors, are used to set the first-stage output to a known value. The designed two-stage telescopic operational amplifier has 41.04[Formula: see text]dB lower frequency gain, 1.81[Formula: see text]GHz gain-bandwidth product (GBW) and 51.9∘ phase margin under 5[Formula: see text]pF load capacitance. The design consumes a total current of 11.9[Formula: see text]mA from a 1.2-V supply voltage. Presented fully differential two-stage telescopic op-amp by using low-voltage design techniques is suitable for active filter in vehicle-to-everything (V2X) applications with 120[Formula: see text][Formula: see text]m[Formula: see text]m layout area.


Author(s):  
Chaiyanut Aueamnuay ◽  
Ajmal Vadakkan Kayyil ◽  
Narayana Bhagirath Thota ◽  
Praveen Kumar Venkatachala ◽  
David J. Allstot

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