Mixed Signal Chip Design Lab CMOS Analog Addition/Subtraction Jaehyun Lim, Kyusun Choi Department of Computer Science and Engineering The Pennsylvania State University CSE598A/EE597G Spring 2006

Mixed Signal Chip Design Lab Addition  Why adder? Neural network Continuous time signal processing application Low power / small size

Mixed Signal Chip Design Lab Addition / Subtraction Using Op-Amp R1 R2Rf V1 V2 = -Rf ( V1/R1 + V2/R2) V1 V2 R1R2 R1 R2 = R2/R1 ( V1 - V2 )

Mixed Signal Chip Design Lab R1R2 V1 V2 = R2/R1 ( V3 – V1 ) + R2/R3 ( V4 – V2 )V3 V4 R2 R1 R3 Addition / Subtraction Using Op-Amp

Mixed Signal Chip Design Lab Other OP-Amp Applications  differentiator / integrator  active filters  I / V converter  positive / negative voltage reference  voltage supply  wave form generator  oscillator  and more…and more…and more…

Mixed Signal Chip Design Lab Addition  Design #1 V 1 /2 + V S -V 1 /2 + V S V 2 /2 + V S -V 2 /2 + V S VxVx VyVy

Mixed Signal Chip Design Lab Addition  Design #1  Two conditions : turn on : saturation

Mixed Signal Chip Design Lab Addition  Design #2

Mixed Signal Chip Design Lab Addition  Design #2 

Mixed Signal Chip Design Lab Addition  Design #3 (Similar to Design #1)

Mixed Signal Chip Design Lab Subtraction  Design #1 (from adder Design #2)

Mixed Signal Chip Design Lab Subtraction  Design #1 

Mixed Signal Chip Design Lab Reference [1] M. Al-Nsour, et al., “Analog Computational Circuits for Neural Network Implementation,” Proceedings of ICECS '99. The 6th IEEE International Conference on Volume 1, 5-8 Sept pp vol.1 [2] S. W. Tsay and R. W. Newcomb, “A Neural-Type Pool Arithmetic Unit,” Circuits and Systems, 1991., IEEE International Sympoisum on June 1991 pp vol.5 [3] A. Diaz-Sanchez, et al., “A Compact High Frequency VLSI Differential Analog Adder,” Circuits and Systems, 1996., IEEE 39th Midwest symposium on Volume 1, Aug pp vol.1 [4] H. Chaoui, “CMOS Analogue Adder,” Electronics Letters Volume 31, Issue 3, 2 Feb pp. 180 – 181 [5] C. Chang, et al., “Low-Voltage Analog Tripler Circuit,” Journal of Analog Integrated Circuits and Signal Processing, vol. 26, pp , Feb [6] R. Fried and C. Enz, “A Family of Very Low-Power Analog Building Blocks Based on CMOS Translinear Loops,” Analog and Mixed IC Design, Proceedings., nd IEEE-CAS Region 8 Workshop on Sept pp. 73 – 78 [7] “An Applications Guide for Op Amps,” National Semiconductor Application Note 20, Feb [8] G. Clayton and Steve Winder, “Operational Amplifiers,” Newnes, 2003

Mixed Signal Chip Design Lab Simulation R1R2 V1 V2 = R2/R1 ( V3 – V1 ) + R2/R3 ( V4 – V2 )V3 V4 R2 R1 R3 2-stage diff amp R1=R2=R3=100 KΩ Addition: V1=V2=0 V Subtraction: V4=V2=0 V

Mixed Signal Chip Design Lab Simulation ( V)( V)

Mixed Signal Chip Design Lab Simulation ( V)( V)( V)

Mixed Signal Chip Design Lab Simulation

Mixed Signal Chip Design Lab Simulation M1~M4: 1.98µ/0.48µ M5, M6: 26.64µ/0.48u

Mixed Signal Chip Design Lab Simulation V0.00 V0.16 V