Analog Devices High Speed, Quad Universal Filter Building Block

     The LTC1264 consists of four identical high-speed, two-stage switched capacitor filters designed for center frequencies up to 250kHz. Each module, along with three to five resistors, can provide secondary functions such as low-pass, high-pass, band-pass, and notch. The center frequency of each second-order section is tuned by an external clock. The clock-to-center frequency ratio is set internally at 20:1, but can be modified with external resistors.

     The aliasing performance of the LTC1264 is improved by double-sampling each second-order portion. The input frequency can be up to twice the clock frequency before any aliasing is detected. Q≤5 and TA < At 85℃, the maximum center frequency is 160kHz. When Q≤2, the maximum center frequency is 250 KHZ. By cascading all four second-order parts, a maximum of 8-order filters can be implemented. A custom integral version of the LTC1264, including internal film resistors, is available.