A 50-MHz CMOS variable gain amplifier for magnetic data storage systems

A variable-gain amplifier (VGA) with a 35-dB range and 50-MHz bandwidth in 2- mu m CMOS is described. The circuit occupies 0.8-mm/sup 2/ active area, dissipates 150 mW, and embodies a semilogarthic relation between gain and control voltage. Although developed for use in magnetic storage read channels, this general-purpose block may be used in a variety of applications.<
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