AN-0991 APPLICATION NOTE One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com Active Filter Evaluation Board for Standard SOIC Op Amps by John Ardizzoni board has provisions for edge-mounted SMA connectors, which simplify testing and integration. The EVAL-FLTR-SO-1RZ active filter evaluation board is designed to work with standard pinout op amps. The filter board enables quick prototyping of two-, four-, or six-pole lowor high-pass Sallen-Key active filters. The board schematic shown in Figure 1 is for a low-pass filter. Converting the board from a low-pass filter to a high-pass filter is accomplished by swapping the location of the filter resistors and capacitors. The C1 R1 C5 R5 VIN R10 C12 C7 10µF +VS RT The active filter evaluation board is bare, which enables the user to customize the filter design. The filter board assembly drawing is shown in Figure 2. All components are 0603 case sizes with the exception of the large bypass capacitors, which are 3216 case sizes. C3 0.1µF + VS+ R2 R7 V+ VS+ C8 0.1µF R12 V+ C13 0.1µF V+ U1 U2 V– C4 0.1µF GND V– C9 0.1µF C6 –VS + R3 –VS AGND R6 VOUT1 R9 R8 R14 R11 R13 VOUT2 Figure 1. Active Filter Evaluation Board Schematic SECONDARY SIDE PRIMARY SIDE 07953-002 R4 C14 V– 0.1µF C11 C10 10µF GND –VS U3 07953-001 C2 R15 VOUT3 AGND Figure 2. Active Filter Evaluation Board Assembly Drawing Rev. A | Page 1 of 2 AN-0991 Application Note NOTES ©2008-2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. AN07953-0-8/10(A) Rev. A | Page 2 of 2