You are here

User Module Datasheet: Two-Pole Elliptical Low-Pass Filter Datasheet ELPF2 V 1.20 (CY8C29/28/24xxx, CY8C27x43) | Cypress Semiconductor

User Module Datasheet: Two-Pole Elliptical Low-Pass Filter Datasheet ELPF2 V 1.20 (CY8C29/28/24xxx, CY8C27x43)

Last Updated: 
Dec 15, 2014
Version: 
1.20

Features and Overview

  • User-programmable gain
  • User-programmable corner frequency (from 20 Hz to 150 kHz), Notch frequency, and damping ratio with no external components
  • Filter corner-frequency stability directly derived from clock accuracy
  • Filter sampling rates up to 1.5 MHz

The ELPF2 User Module implements a general purpose two-pole elliptical low-pass filter with a pair of elliptical zeroes at user selectable frequencies. The zeroes result in notches in the transfer function, intended to get rid of specific frequencies. Damping ratio are functions of the clock frequency and the ratios of the capacitor values calculated automatically based on the user parameters preset (Corner, Sample and Notch frequency, Gain, Filter type). Any of the classical all-pole filter configurations (Butterworth, Bessel, and Chebyshev) can be implemented. You can also select custom filter configuration, enter values for complex poles. The corner frequency can be set very accurately or adjusted by controlling the sample rate clock. The filter output can drive the analog output bus.