The TLC14CD from Texas Instruments is a 4th-order Butterworth low-pass switched capacitor filter Integrated Circuit rated at 30 kHz, in an 8-SOIC package.
The TLC14ID from Texas Instruments is a 4th-order Butterworth low-pass switched capacitor active filter Integrated Circuit rated 30 kHz, in an 8-SOIC package.
The TLC14IDG4 from Texas Instruments is a Butterworth low-pass switched-capacitor filter Integrated Circuit, 4th order at 30 kHz, in an 8-SOIC package.