TY - JOUR
T1 - On the evaluation of the exact output of a switched continuous-time filter and applications
AU - Arnaud, Alfredo
AU - Miguez, Matías R.
PY - 2008/7
Y1 - 2008/7
N2 - In this paper, a study of the operation of switched continuous-time filters (SCTFs), defined as continuous-time filters with elements that are alternatively switched on and off in the signal path, is conducted. A well-known example is the use of switched resistors to multiply their value, but the universe of applications is wider. First, a detailed calculation of the output of an SCTF in the frequency domain, which allows the examination of any SCTF in a general framework, is presented. This result particularly explains the resistor multiplication effect. Three application examples using switched elements are presented and examined as SCTFs: a nonideal sample & hold, a switched active filter that is tuned by varying the duty cycle of the switching, and a switched Gm-C filter to implement a chopper amplifier. In all cases, the theoretical background allows the examination of circuit behavior and limitations, and the analysis is supported by measurements or transient simulations.
AB - In this paper, a study of the operation of switched continuous-time filters (SCTFs), defined as continuous-time filters with elements that are alternatively switched on and off in the signal path, is conducted. A well-known example is the use of switched resistors to multiply their value, but the universe of applications is wider. First, a detailed calculation of the output of an SCTF in the frequency domain, which allows the examination of any SCTF in a general framework, is presented. This result particularly explains the resistor multiplication effect. Three application examples using switched elements are presented and examined as SCTFs: a nonideal sample & hold, a switched active filter that is tuned by varying the duty cycle of the switching, and a switched Gm-C filter to implement a chopper amplifier. In all cases, the theoretical background allows the examination of circuit behavior and limitations, and the analysis is supported by measurements or transient simulations.
KW - Analog processing circuits
KW - Analog processing circuits example
KW - Continuous-time filters
KW - Filter theory
KW - Frequency-domain analysis
KW - Over switched- capacitor filters
KW - Switched systems
UR - http://www.scopus.com/inward/record.url?scp=53849102569&partnerID=8YFLogxK
U2 - 10.1109/TCSI.2008.917999
DO - 10.1109/TCSI.2008.917999
M3 - Artículo
AN - SCOPUS:53849102569
SN - 1057-7122
VL - 55
SP - 1421
EP - 1429
JO - IEEE Transactions on Circuits and Systems I: Regular Papers
JF - IEEE Transactions on Circuits and Systems I: Regular Papers
IS - 6
ER -