摘要:
The present invention discloses a circuit (10) adapted to compensate for RMR variations and shunt resistance across the RMR comprising a first current source (idc1) coupled to a first resistor (r1), a second current source (idc2) coupled to a second resistor (r2), wherein the first resistor (r1) and the second resistor (r2) are coupled, a resistive sensor (RMR) coupled on either side to a third resistor (r3) and to a fourth resistor (r4), and a transconductance feedback block (GM) coupled to the resistive sensor (RMR), the third resistor (r3), and to the fourth resistor (r4).
摘要:
A write drive circuit (40) for a hard disk drive selectively providing a current mode operation for high speed data write of a single channel, and selectively providing a voltage mode operation during a servo write operation. A central buffer has a first circuit (50) providing a current mode drive signal to a head during a single channel write operation, and a second circuit (52) providing a voltage mode drive signal for multi-channel servo write operation. The outputs of both circuits (50, 52) is provided over a common differential connection (T1) feeding a pre-driver circuit (70) adapted to drive one or many heads, as determined by head select control lines (72). The circuit provides >1.6 Gb/s data write speed in single channel write operation, and has an architecture utilizing only two signal lines for four channels.