Low Power, 8th Order Progressive Elliptic, Lowpass Filter

The LTC1069-1 is a monolithic 8th order lowpass filter featuring clock-tunable cutoff frequency and 2.5mA power supply current with a single 5V supply. An additional feature of the LTC1069-1 is operation with a single 3.3V supply.

The cutoff frequency (fCUTOFF) of the LTC1069-1 is equal to the clock frequency divided by 100. The gain at fCUTOFFM is –0.7dB and the typical passband ripple is ±0.15dB up to 0.9fCUTOFF. The stopband attenuation of the LTC1069-1 features a progressive elliptic response reaching 20dB attenuation at 1.2fCUTOFF, 52dB attenuation at 1.4fCUTOFF and 70dB attenuation at 2fCUTOFF.

With ±5V supplies, the LTC1069-1 cutoff frequency can be clock-tuned up to 12kHz; with a single 5V supply, the maximum cutoff frequency is 8kHz.

The low power feature of the LTC1069-1 does not penalize the device’s dynamic range. With ±5V supplies and an input range of 0.3VRMS to 2.5VRMS, the signal-to-(noise + THD) ratio is ≥70dB. The wideband noise of the LTC1069-1 is 110μVRMS. Other filter responses with lower power or higher speed can be obtained. Please contact LTC marketing for details.

The LTC1069-1 is available in 8-pin PDIP and 8-pin SO packages.

Applications

* Telecommunication Filters

* Antialiasing Filters

* 8th Order Elliptic Filter in SO-8 Package

* Operates from Single 3.3V to ±5V Power Supplies

* –20dB at 1.2fCUTOFF

* –52dB at 1.4fCUTOFF

* –70dB at 2fCUTOFF

* Wide Dynamic Range

* 110μVRMS Wideband Noise

* 3.8mA Supply Current with ±5V Supplies

* 2.5mA Supply Current with Single 5V Supply

* 2mA Supply Current with Single 3.3V Supply