MAX281ACPA+ (MAXIM INTEGRATED PRODUCTS)

The MAX281ACPA+ from Maxim Integrated Products is a 5th order, zero-error, Bessel low pass filter in 8 pin DIP package. This 5th order all-pole instrumentation low pass filter with no DC error. The filter uses an external resistor and capacitor to isolate the integrated circuit from the DC signal path thus providing DC accuracy. The external resistor and capacitor with the on-chip 4th order switched capacitor filter from a 5th order Bessel low pass filter. Bessel low pass filters provide linear phase (constant group delay) response from DC to beyond the filter cut-off frequency with some function in stopband attenuation. The filter cut-off frequency is set by a clock which can be either internally generated or externally provided. The clock to cut-off frequency ratio of 101 allows easy removal of clock ripple. Typical applications include anti-aliasing filters, data loggers, digital voltmeters, weigh scales and strain gauge.