MAX7490

19-1768; Rev 1; 4/09 Dual Universal Switched-Capacitor Filters MAX7490/MAX7491 General Description The MAX7490/MAX7491 consist of two identical lowpower, low-voltage, wide dynamic range, rail-to-rail, 2nd-order switched-capacitor building blocks. Each of the two filter sections, together with two to four external resistors, can generate all standard 2nd-order functions: bandpass, lowpass, highpass, and notch (band reject). Three of these functions are simultaneously available. Fourth-order filters can be obtained by cascading the two 2nd-order filter sections. Similarly, higher order filters can easily be created by cascading multiple MAX7490/MAX7491s. Two clocking options are available: self-clocking (through the use of an external capacitor) or external clocking for tighter cutoff frequency control. The clockto-center frequency ratio is 100:1. Sampling is done at twice the clock frequency, further separating the cutoff frequency and Nyquist frequency. The MAX7490/MAX7491 have an in...