Abstract: A lead impedance stimulation architecture and a dual current source and sink methodology to output a biphasic current pulse and measure a resulting induced voltage across the stimulation electrodes to determine lead impedance. A common mode capacitance on the electrode interface may have little impact on the stimulation architecture of this disclosure allowing for fast voltage rise time and consistent and accurate impedance measurement. In addition, the dual source and sink includes a monitor circuit on each of the source and the sink circuitry. In the event of an open circuit indicating a lead breakage, loose connection, lead migration, insulation leak, and so on, the monitor circuit may provide an output to indicate specifically which electrode is unable to reach the correct current stimulation amplitude. In this manner the techniques of this disclosure, may also detect a lead break in a single lead impedance measurement.

Abstract: A lead impedance stimulation architecture and a dual current source and sink methodology to output a biphasic current pulse and measure a resulting induced voltage across the stimulation electrodes to determine lead impedance. A common mode capacitance on the electrode interface may have little impact on the stimulation architecture of this disclosure allowing for fast voltage rise time and consistent and accurate impedance measurement. In addition, the dual source and sink includes a monitor circuit on each of the source and the sink circuitry. In the event of an open circuit indicating a lead breakage, loose connection, lead migration, insulation leak, and so on, the monitor circuit may provide an output to indicate specifically which electrode is unable to reach the correct current stimulation amplitude. In this manner the techniques of this disclosure, may also detect a lead break in a single lead impedance measurement.

Abstract: A method for calibrating a reflection compensator is provided. A delay is initially set to a predetermined minimum, and an input pulse is transmitted across a transmission line. A compensation current is then applied after the delay. The reflection from the transmission line is digitized to generate a measurement, and a determination is made as to whether the compensation current substantially compensates for the reflection. If the compensation current does not substantially compensate for the reflection, then the delay is adjusted, and the process is repeated until the compensation current substantially compensates for the reflection.

Abstract: A method for calibrating a reflection compensator is provided. A delay is initially set to a predetermined minimum, and an input pulse is transmitted across a transmission line. A compensation current is then applied after the delay. The reflection from the transmission line is digitized to generate a measurement, and a determination is made as to whether the compensation current substantially compensates for the reflection. If the compensation current does not substantially compensate for the reflection, then the delay is adjusted, and the process is repeated until the compensation current substantially compensates for the reflection.

Abstract: A disc drive includes a recording head preamplifier circuit having a plurality of preamplifiers. Each preamplifier includes a receiver circuit and a preamplifier enable circuit. The receiver circuit receives a serial command having command address bits. The preamplifier enable circuit is operatively coupled to the receiver circuit and generates an enable output for enabling the preamplifier when the command address bits match a first predetermined logic pattern which is unique to chat preamplifier and when the command address bits match a second predetermined logic pattern which is universal to the plurality of preamplifiers.