MF6

MF6 6th Order Switched Capacitor Butterworth Lowpass Filter June 1999 MF6 6th Order Switched Capacitor Butterworth Lowpass Filter General Description The MF6 is a versatile easy to use, precision 6th order Butterworth lowpass active filter. Switched capacitor techniques eliminate external component requirements and allow a clock tunable cutoff frequency. The ratio of the clock frequency to the lowpass cutoff frequency is internally set to 50 to 1 (MF6-50) or 100 to 1 (MF6-100). A Schmitt trigger clock input stage allows two clocking options, either self-clocking (via an external resistor and capacitor) for stand-alone applications, or an external TTL or CMOS logic compatible clock can be used for tighter cutoff frequency control. The maximally flat passband frequency response together with a DC gain of 1 V/V allows cascading MF6 sections for higher order filtering. In addition to the filter, two independent CMOS op amps are included on the die and are useful for any general signal conditioning applications. Features n n n n n n No external components Cutoff frequency accuracy of ± 0.3% typical Cutoff frequency range of 0.1 Hz to 20 kHz Two uncommitted op amps available 5V to 14V total supply voltage Cutoff frequency set by external or internal clock Block and Connection Diagrams All Packages DS005065-2 Top View Order Number MF6CWM-50 or MF6CWM-100 See NS Package Number M14B DS005065-1 TRI-STATE ® is a registered trademark of National Semiconductor Corporation. © 1999...