The LTC1062CJ8 from Analog Devices Inc. is a Butterworth low-pass switched-capacitor filter Integrated Circuit, 5th order at 20 kHz, in an 8-CERDIP package.
The LTC1062CSW#TRPBF from Analog Devices Inc. is a 5th-order Butterworth low-pass switched capacitor active filter Integrated Circuit at 20 kHz, in a 16-SO package.
The LTC1062CSW#PBF from Analog Devices Inc. is a Butterworth low-pass switched capacitor filter Integrated Circuit, 5th order with 20 kHz cutoff, in a 16-SO package.
The LTC1062CN8 from Analog Devices Inc. is a 5th-order Butterworth low-pass switched capacitor active filter Integrated Circuit with a 20 kHz cutoff in an 8-PDIP package.