LTC1066-1

The LTC1066-1 is an 8th order elliptic lowpass filter whichsimultaneously provides clock-tunability and DC accu-racy. The unique and proprietary architecture of the filterallows 14 bits of DC gain linearity and a maximum of1.5mV DC offset. An external RC is required for DCaccurate operation. With ±7.5V supplies, a 20k resistorand a 1µF capacitor, the cutoff frequency can be tunedfrom 800Hz to 100kHz. A clock-tunable 10Hz to 100kHzoperation can also be achieved (see Typical Applicationsection).

The filter LTC1066-1 does not require any external active componentssuch as input/output buffers. The input/output impedanceis 500MΩ/0.1Ω and the output of the filter can source orsink 40mA. When pin 8 is connected to V+, the clock-to-cutoff frequency ratio is 50:1 and the input signal issampled twice per clock cycle to lower the risk of aliasing.

For frequencies up to 0.75fCUTOFF, the passband ripple is±0.15dB. The gain at fCUTOFF is 1dB and the filter'sstopband attenuation is 80dB at2.3fCUTOFF. Linear phaseoperation is also available with a clock-to-cutoff frequencyratio of 100:1 when pin 8 is connected to ground.

The LTC1066-1 is available in an 18-pin SOL package.