Macromodeling and demonstration of the LT6600 amplifier and lowpass filter

Abstract

The goal of this thesis is to demonstrate the abilities of the Sevastopoulos-LaPorte active low-pass filter topology in Linear Technology Corporation's LT6600 integrated circuit (IC). The thesis is split into two parts, representing two facets of how engineers will evaluate the LT6600: by simulation and in the laboratory. The LT6600-10 macromodel and its design methodology is presented, as well as comparisons of macromodel characteristics with measured characteristics of the LT6600-10 IC. For the lab demonstration portion, the LT6600-2.5 was integrated into a digital code-division multiple access (CDMA) communications system, complete with transmit and receive sections. The performance of the LT6600 in this system was shown to be as good as or better than most conventional filtering approaches. When implemented in a communications system., the LT6600-10 required up to 13 less components than other reasonable filtering options and provided 4th-order signal attenuation with only 14 nV/[square root]Hz of voltage noise spectral density.