mos four-quadrant analog multiplier
DESCRIPTION
MOS Four-Quadrant Analog Multiplier. Saurabh Gupta(Y4392) Vikas Kumar Sharma(Y4482). Guided By: Prof. S.Qureshi. Introduction. Various Applications Modulation Demodulation Wave Shaping Many Designs have limitations of two-quadrant multiplication only. Concept. - PowerPoint PPT PresentationTRANSCRIPT
MOS Four-Quadrant Analog Multiplier
Saurabh Gupta(Y4392)
Vikas Kumar Sharma(Y4482)
Guided By:Prof. S.Qureshi
Introduction
Various Applications Modulation Demodulation Wave Shaping
Many Designs have limitations of two-quadrant multiplication only
Concept
The basic motivation behind the design is :
This have been a favorite of analog multiplier designs but has its own limitations (later)
MOS Properties
MOSFET’s have the special property of squaring current in saturation
This can be exploited to make the sum/difference Squaring Circuits.
Design
The design has two major parts : Sum-Squaring Circuit Difference-Squaring Circuit
The difference of the two outputs gives the multiplication with some constant gain
Sum-Squaring Circuit
Schematic
Design Equations
Output Voltage ->
Max. Input voltage (for linear operation)
Simulation (Half Circuit)
Complete Circuit
Simulation Results
Highly Linear behavior
Almost zero offset
Distortion at high Input Voltages
DC Transfer Characteristics
DC Transfer Characteristics(Contd..)
Conclusion
The circuit is found to be working satisfactorily for differential input voltages up to 0.5 V
The Circuit is found to have a -0.2dB gain drop at 1 Ghz(suited for high frequency applications)
It is sensitive to component mismatch
Limitations
Body-effect neglected in the design CLM modifies the behavior from expected Component Mismatch will result in harmonic
impurity
Acknowledgement
We are thankful to Dr. Qureshi for giving us this opportunity and to our TA’s who were always there for helping us out.
References
“An MOS Four-Quadrant Analog Multiplier Using Simple Two-Input Squaring Circuits with Source Followers” by Ho-Jun Song & Choong-Ki Kim, IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 25, NO. 3, JUNE 1990
Thank you…