LMF100

Contents

The LMF100 consists of two independent general purpose high performance switched capacitor filters. With an external clock and 2 to 4 resistors, various second-order and first-order filtering functions can be realized by each filter block. Each block has 3 outputs. One output can be configured to perform either an allpass, highpass, or notch function. The other two outputs perform bandpass and lowpass functions. The center frequency of each filter stage is tuned by using an external clock or a combination of a clock and resistor ratio. Up to a 4th-order biquadratic function can be realized with a single LMF100. Higher order filters are implemented by simply cascading additional packages, and all the classical filters (such as Butterworth, Bessel, Elliptic, and Chebyshev) can be realized.

The LMF100 is fabricated on National Semiconductor's high performance analog silicon gate CMOS process, LMCMOS™. This allows for the production of a very low offset, high frequency filter building block. The LMF100 is pin-compatible with the industry standard MF10, but provides greatly improved performance.

• Wide 4V to 15V power supply range
• Operation up to 100 kHz
• Low offset voltage: typically (50:1 or 100:1 mode): Vos1 = ±5 mV Vos2 = ±15 mV Vos3 = ±15 mV
• Low crosstalk -60 dB
• Clock to center frequency ratio accuracy ±0.2% typical
• f₀ × Q range up to 1.8 MHz
• Pin-compatible with MF10