Title :
Harmonic distortion in switched-current audio memory cells
Author :
Martins, Jorge M. ; Dias, Victor F.
Author_Institution :
Inst. Superior Tecnico, Tech. Univ. Lisbon, Portugal
fDate :
3/1/1999 12:00:00 AM
Abstract :
Harmonic distortion in switched-current memory cells is investigated, and closed-form equations are presented concerning the effects of threshold voltage mismatch, signal dependent output conductance, and clock injection. We show that output conductance can be the main source of distortion in basic cells, but clock injection is dominant in regulated cascode (RgC), grounded-gate regulated cascode, and Shah-Toumazou cells. Concerning the V-I converter, we show that if this is simply a resistor at the input of either a GGRgC or an RgC Shah-Toumazou cell, the resulting distortion is very low. Our results have been confirmed by SPICE simulations and by measurements made on two 1.2 μm CMOS prototype chips
Keywords :
CMOS analogue integrated circuits; analogue processing circuits; analogue storage; harmonic distortion; network analysis; switched current circuits; timing; 1.2 micron; CMOS prototype chips; SI audio memory cells; Shah-Toumazou cells; V-I converter; clock injection; closed-form equations; grounded-gate regulated cascode; harmonic distortion; regulated cascode; signal dependent output conductance; switched-current audio memory cells; threshold voltage mismatch; Associate members; CMOS technology; Circuit simulation; Clocks; Equations; Harmonic distortion; Resistors; Switches; Switching circuits; Threshold voltage;
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on
