AN-0991: Active Filter Evaluation Board for Standard SOIC Op Amps

by John Ardizzoni Download PDF

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 low or 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 board has provisions for edge-mounted SMA connectors, which simplify testing and integration.

Figure 1. Active Filter Evaluation Board Schematic.

Figure 1. Active Filter Evaluation Board Schematic.

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, whichare 3216 case sizes.

Figure 2. Active Filter Evaluation Board Assembly Drawing.

Figure 2. Active Filter Evaluation Board Assembly Drawing.

Author

John Ardizzoni

John Ardizzoni

John started at Analog Devices in 2002, as an Application Engineer in the High Speed Amplifier group. Prior to joining Analog Devices John worked for IBM, in RFIC applications and at M/A-COM for 20 years. John is also co-author of Analog Devices Rarely Asked Questions (RAQ's) column. John has over 30 years experience in the electronics industry, and has authored numerous articles and design ideas.