Abstract
A procedure for the design of allpole filters with low sensitivity to component tolerance is presented. The filters are based on resistance-capacitance (RC) ladder structures combined with single operational amplifiers. It is shown that by the use of impedance tapering, in which L-sections of the RC ladder are successively impedance-scaled upwards, from the driving source to the amplifier input, the sensitivity of the filter characteristics to component tolerances can be significantly decreased. Impedance tapering is achieved by the appropriate choice of component values. The design procedure, therefore, adds nothing to the cost of conventional circuits; component count and topology remain unchanged, whereas the component values selected for impedance tapering account for the considerable decrease in componenttolerance sensitivity.
Original language | English |
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Pages (from-to) | 1009-1026 |
Number of pages | 18 |
Journal | IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing |
Volume | 46 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1999 |
Externally published | Yes |
Keywords
- Allpole filters
- Biquadratic active filters
- Impedance tapering
- Low-sensitivity active filters
- Third-order active filters