Abstract: A magnetic-head write-driver circuit includes a write-driver circuit and a by-pass driver circuit coupled in parallel to a signal path between the input and the output of the magnetic-head write-driver circuit. The write-driver circuit receives an input signal having transitions and outputs a first write signal related to the input signal. The by-pass driver circuit outputs an assist signal that is coupled to the first write signal to form an output write signal. The assist signal is related to transitions of the first write signal and assists in shortening reversal time of the transitions of a write signal by producing “overshoots” in the write signal at the time of the transitions. Additionally, the assist signal assists in charging and discharging a parasitic capacitance associated with an output of the magnetic-head write-driver circuit. The assist signal can add a current to, and/or enforce a voltage on, the first write signal to form the output write signal.

Abstract: A circuit and method for detecting write-safe conditions for a magnetic storage device The circuit includes an electrical interconnect, a write-safe circuit, a write-driver circuit, a read amplifier and a read/write element. The electrical interconnect has a write path and a read path. A read element is coupled to one end of the read path, while the read amplifier is coupled to the other end of the read path. A write element is coupled to an end of the write path that is in proximity to the read element, while a write-output circuit is coupled to the other end of the write path. Preferably, the write element and the read element are part of a magneto-resistive head, such as a Piggyback-Magneto-Resistive head. The write-safe circuit, coupled to the read amplifier, detects a write-safe condition based on a signal induced into the read path by a write signal on the write path.

Abstract: A data storage system comprises magnetoresistive (MR) sensing elements for sensing data from a recording medium that is referenced to ground, and an amplifier circuit including a biasing stage, an amplifying stage, and a matching stage, each referenced to a common supply voltage source and to ground. The biasing stage includes a reference current source for selectively biasing each MR element with a constant current and, in so doing, developing a single-ended voltage signal having a first dc component. The amplifying stage converts the single-ended voltage signal into an amplified single-ended output voltage signal having a second dc component but in which the first dc component is eliminated. The matching stage creates a bias and imposes said bias on the amplifying stage for converting the single-ended output voltage signal to a differential output voltage signal in which the second dc component is eliminated.

Abstract: Writing of data on a storage disk by an inductive magnetic transducer is modulated by write driver circuitry that includes a supply voltage as low as three volts provided by a source referenced to ground, and a bias current source connected to either the supply voltage source or ground. Two bias control switches respectively direct the bias current to one or the other of two current gain circuits according to whether a positive or a negative input terminal has a preselected polarity. The gain circuits selectively respond to the bias currents supplied by the associated control switch for amplifying the bias current to remove a write current from a respective associated terminal of the transducer.