General Description
The MAX7490/MAX7491 consist of two identical low power, 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.

Features
♦ Dual 2nd-Order Filter in a 16-Pin QSOP Package
♦ High Accuracy Q Accuracy: ±0.2% Clock-to-Center Frequency Error: ±0.2%
♦ Rail-to-Rail Input and Output Operation
♦ Single-Supply Operation: +5V (MAX7490) or +3V (MAX7491)
♦ Internal or External Clock
♦ Highpass, Lowpass, Bandpass, and Notch Filters
♦ Clock-to-Center Frequency Ratio of 100:1
♦ Internal Sampling-to-Center Frequency Ratio of 200:1
♦ Center Frequency up to 40kHz
♦ Easily Cascaded for Multipole Filters
♦ Low-Power Shutdown: < 1µA Supply Current

Applications
    Tunable Active Filters
    Multipole Filters
    ADC Anti-Aliasing
    Post-DAC Filtering
    Adaptive Filtering
    Phase-Locked Loops (PLLs)
    Set-Top Boxes