Demonstration circuit DC675B is for the evaluation of filter circuits using an LT1568. The LT1568 is a dual 2nd order active-RC filter building block with precision ±0.75% capacitors and low noise op amps with 180MHz GBW trimmed to ±10% maximum variation. The ±10% GBW variation of the LT1568 op amps allows for minimizing the higher frequency error by decreasing resistor values. The cutoff or center frequency (fC) range of an LT1568 filter is 200kHz to 10MHz (5MHz for a bandpass filter). The low limit of 200kHz was chosen only to minimize resistor noise and DC offsets (using external capacitors the fC frequency can be less than 200kHz).