CONTINUOUS TIME FILTER

The Continuous Time Filter (CTF) provides pulse shaping of the input signal by means of boost control, frequency cutoff, and asymmetry control. The CTF topology is a 7th-order Bessel filter, implemented with 3 bi-quads and one Gmc cell. The user can program the cutoff frequency from 6 to 30MHz setting the corner frequency of the filter. Boost capability equalizes the amplitude across the frequency of interest, and can be used for a extension of bandwidth, as well as pulse slimming. Boost can be set with symmetry or with asymmetry. The symmetry does not affect the phase, but the asymmetry allows +/-30% phase adjustment. The filter is tuned to allow for flat group delay.

FEATURES

• 7^th-order Bessel Filter
• 2 independently controlled zeroes
• Flat Group Delay +/- 5% up to 1.5* Fc, without boost
• Programmable Boost: 0 to 10dB
• Programmable Asymmetry: +/- 30%
• Programmable Cut-off: 6-30MHz total range

SYSTEM OVERVIEW

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