TY - JOUR
T1 - Low-power, low-noise, active-RC band-pass filters using a 'lossy' LP-BP transformation
AU - Jurisic, Drazen
AU - Mijat, Neven
AU - Moschytz, George S.
PY - 2013/1
Y1 - 2013/1
N2 - A new and straightforward design procedure for simple canonical topologies of allpole, active-RC, low-selectivity band-pass (BP) filters, with low sensitivity to component tolerances is presented. The procedure is primarily intended for discrete-component, low-power filter applications using just one amplifier for relatively high-order filters. The design procedure starts out with an 'optimized' low-pass (LP) prototype filter, yielding an 'optimized' BP filter, whereby the wealth of 'optimized' single-amplifier LP filter designs can be exploited. Using a so-called 'lossy' LP-BP transformation, closed-form design equations for the design of second- to eighth-order, single-amplifier BP filters are presented. The low sensitivity, low power consumption, and low noise features of the resulting circuits, as well as the influence of the finite gain-bandwidth product and component spread, are demonstrated for the case of a fourth-order filter example. The optimized single-opamp fourth-order filter is compared with other designs, such as the cascade of optimized Biquads. Using PSpice with a TL081 opamp model, the filter performance is simulated and the results compared and verified with measurements of a discrete-component breadboard filter using 1% resistors, 1% capacitors, and a TL081 opamp.
AB - A new and straightforward design procedure for simple canonical topologies of allpole, active-RC, low-selectivity band-pass (BP) filters, with low sensitivity to component tolerances is presented. The procedure is primarily intended for discrete-component, low-power filter applications using just one amplifier for relatively high-order filters. The design procedure starts out with an 'optimized' low-pass (LP) prototype filter, yielding an 'optimized' BP filter, whereby the wealth of 'optimized' single-amplifier LP filter designs can be exploited. Using a so-called 'lossy' LP-BP transformation, closed-form design equations for the design of second- to eighth-order, single-amplifier BP filters are presented. The low sensitivity, low power consumption, and low noise features of the resulting circuits, as well as the influence of the finite gain-bandwidth product and component spread, are demonstrated for the case of a fourth-order filter example. The optimized single-opamp fourth-order filter is compared with other designs, such as the cascade of optimized Biquads. Using PSpice with a TL081 opamp model, the filter performance is simulated and the results compared and verified with measurements of a discrete-component breadboard filter using 1% resistors, 1% capacitors, and a TL081 opamp.
KW - RC-RC network transformation
KW - analog filters
KW - discrete-component active-RC filters
KW - lossy LP-BP transformation
KW - low-power
KW - low-sensitivity active-RC filters
UR - http://www.scopus.com/inward/record.url?scp=84872290477&partnerID=8YFLogxK
U2 - 10.1002/cta.782
DO - 10.1002/cta.782
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AN - SCOPUS:84872290477
SN - 0098-9886
VL - 41
SP - 15
EP - 32
JO - International Journal of Circuit Theory and Applications
JF - International Journal of Circuit Theory and Applications
IS - 1
ER -