A Detailed Model of Cyclostationary Noise in Switched-Resistor Circuits

The Switched-Resistor (S-R) technique is becoming more and interesting to implement low-voltage low-power active- RC filters with high tuning range front-end amplifiers for biomedical circuits systems. This approach exploits MOS switches driven by a duty-cycle-controlled clock signal achieve tunability of the equivalent resistance and, hence, time constant. Since S-R can be considered as linear periodically variant (LPTV) systems sampled outputs, we exploit theory adjoint (inter-reciprocal) network in order develop detailed model cyclostationary noise involved this kind circuits. proposed allows gain insight into different sources transfer functions involved, highlighting circuit parameters on which depends. Validation has been carried out comparing analytical results against periodic simulations referring commercial 130nm CMOS process. validation activity confirmed good accuracy provided some useful design guidelines optimize performance