High-transition-rate, low-supply-voltage write driver circuitry for magnetic inductive write head

A data storage system comprising:

• a data storage disk;
• an inductive magnetic transducer for writing data on the disk;
• and
• write driver circuitry including:
• a single supply voltage source referenced to ground;
• a source providing a bias current and connected to either the supply voltage source or ground;
• positive and negative data input terminals;
• two current gain circuits;
• two bias control switches, each respectively directing the bias current to one or the other of the gain circuits according to which of said input terminals is low;
• one of said gain circuits being responsive to the bias current to amplify the bias current to remove a write current from one terminal of the transducer when one of said input terminals is low, and the other gain circuit being responsive to the bias current to amplify the bias current to remove the write current from another terminal of the transducer when the other input terminal is low;
• and
• two current source switches, each current source switch and an associated one of the gain circuits being connected in series between the supply voltage source and ground via respective separate paths that extend in parallel between the supply voltage source and ground, and each current source switch being connected to a respective one of the input terminals and to a respective one of the terminals of the transducer for alternatively preventing or allowing the write current from flowing into an associated respective terminal of the transducer according to which of the input terminals is low.

A method for modulating the writing of data on a magnetic storage disk by an inductive magnetic transducer, said method comprising the steps of:

• providing a single supply voltage source referenced to ground;
• deriving a bias current from a source connected either to the supply voltage source or ground;
• providing two current source switches;
• connecting each current source switch and an associated one of two gain circuits in series between the supply voltage source and ground via respective separate paths that extend in parallel between the supply voltage source and ground;
• directing the bias current to one or the other of the gain circuits according to whether a positive or a negative input terminal is at a preselected polarity;
• and
• amplifying the directed bias current for removing a write current from one of the two terminals of the transducer, and concurrently allowing the write current to flow into the other terminal of the transducer.

Circuitry for modulating the writing of data on a magnetic storage disk, comprising:

• a single supply voltage source referenced to ground;
• an inductive write transducer;
• a pair of current source switches each for selectively supplying a write current to a respective terminal of the transducer;
• two data input terminals;
• a pair of current gain circuits;
• each current source switch and an associated one of the gain circuits being connected in series between the supply voltage source and ground via separate parallel paths;
• and
• two bias control switches, each for respectively directing a bias current to an associated one of the gain circuits according to which of said input terminals is at a preselected polarity for causing the gain circuit receiving the bias current to amplify it to remove the write current from an associated terminal of the transducer.