DESCRIPTION
The LTC®1059 consists of a general purpose, high performance, active filter building block and an uncommitted op amp. The filter building block together with an external clock and 2 to 5 resistors can produce various 2nd order functions which are available at its three output pins. Two out of three always provide lowpass and bandpass functions while the third output pin can produce notch or highpass or allpass. The center frequency of these functions can be tuned from 0.1Hz to 40kHz and is dependent on an external clock or an external clock and a resistor ratio. The filter can handle input frequencies up to 100kHz. The uncommitted op amp can be used to obtain additional allpass and notch functions, for gain adjustment or for cascading techniques.

FEATURES
■ All Filter Parameters Guaranteed Over Temperature
■ Wide Center Frequency Range (0.1Hz to 40kHz)
■ Low Noise Wide Dynamic Range
■ Operation from ±2.5V and Supply ±8V
■ Low Power Consumption
■ Guaranteed Clock-to-Center Frequency Accuracy of 0.8% or Better
■ Guaranteed Low Offset Voltages over Temperature
■ Very Low Center Frequency and Q Tempco
■ Clock Input T2L or CMOS Compatible
■ Separate Highpass (or Notch or Allpass), Bandpass, Lowpass Outputs

APPLICATIONS
■ Sinewave Oscillators
■ Sweepable Bandpass/Notch Filters
■ Full Audio Frequency Filters
■ Tracking Filters