Hard disk storage system including a first transistor type and a second transistor type where a first voltage level pulls one of a first pair of transistors and a second voltage level pulls one of a second pair of transistors at substantially the same time

Abstract

A write driver produces balanced voltages across head by using the input write data drive transistors of a slower transistor type (typically PNP) on one half of an H-bridge configuration, while transistors of a faster transistor type (typically NPN) in the other half of the H-bridge configuration are driven indirectly by transistors of the slower type, with a trans-resistance in series with transistors of the faster type. Accordingly, the voltage nodes on either side of the write head are pulled to Vcc and Vee symmetrically. A trans-resistance block () uses current sources to pull current from capacitive nodes for faster switching.