Method for implementing high frequency programmable poles and zeros in disk drive preamplifiers

摘要

A pole and zero circuit for changing the position of a pole, or a zero, of an amplifier including a capacitor to change the position of the pole or zero for the amplifier, a first current path for the capacitor, a variable impedance device in the first current path to connect the capacitor to the amplifier, and a current source to control the impedance of the variable impedance device.