The MAX7491EEE+ is a dual, universal, 2nd order switched capacitor filter in 16 pin QSOP package. It consists of two identical low power, low voltage, wide dynamic range and rail to rail 2nd order switched capacitor building blocks. Each of two filter sections together with two to four external resistors can generate all standard 2nd order functions such as bandpass, low pass, high pass and notch (band reject). Three of these functions are simultaneously available. Fourth order filters can be obtained by cascading two 2nd order filter sections. Similarly higher order filters can easily be created by cascading multiple MAX7491 devices. The self clocking (through the use of an external capacitor) or external clocking options are available for tighter cut off frequency control. The MAX7491 operates from single +3V supply and used in tunable active filters, multipole filters, ADC anti-aliasing, post DAC filtering, adaptive filtering and phase locked loops (PLL).
● Supply voltage range from 2.7V to 3.6V
● Operating temperature range from -40°C to 85°C
● High accuracy with ±0.2% Q accuracy, ±0.2% clock to centre frequency error
● Power supply current of 3.5mA
● Internal or external clock
● Internal sampling to centre frequency ratio of 200:1 and clock to centre frequency ratio is 100:1
● Maximum clock frequency of 4MHz and centre frequency range from 0.001KHz to 40KHz
● Easily cascaded for multipole filters
● Less than 1µA low power shutdown mode
● Crosstalk of -60dB at fIN = 10KHz and noise of 60µVrms (mode 1, R1 = R2 = R3 =10Kohm)
