MAX7490EEE

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 internal rail splitter

that establishes a precise common voltage needed for

single-supply operation. The MAX7490 operates from a

single +5V supply and the MAX7491 operates from a

single +3V supply. Both devices feature a low-power

shutdown mode and come in a 16-pin QSOP package.