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:

Applications

    Tunable Active Filters

    Multipole Filters

    ADC Anti-Aliasing

    Post-DAC Filtering

    Adaptive Filtering

    Phase-Locked Loops (PLLs)

    Set-Top Boxes