System and method for coarse gain control of wide band amplifiers

摘要

A system and method for a data detection circuit is provided in which separate coarse gain amplifiers and fine gain amplifiers are utilized. The coarse gain amplifiers may include drain switching of transistors in order to modify the amplifier gain. More particularly, drain switching may be utilized to selectively switch in and out different differential input transistor pairs and/or different current sources. In this manner the gain of the amplifier may be adjusted to one of a variety of different coarse gain control levels. The coarse gain control provided allows for gain adjustments without significantly decreasing the bandwidth of the amplifier. In a preferred embodiment the system and method may be utilized for data detection circuits utilized in conjunction with optical disks.