Above rail writer driver
OwnerReza Sharifi, Indumini Ranmatherinventors
Life of this patent
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Abstract
The present invention achieves technical advantages as a write driver preamplifier circuit providing a higher output voltage than that of the supply voltage, and utilizing smaller capacitors. The circuit generates a differential voltage across the writer output larger than the supply voltage. Advantageously, during the DC portion of the write current, such as when HWX and HWY are almost at ground, small capacitors are each charged by a capacitive driver to half of the total supply voltage. When the writer toggles, the capacitor drivers switch the capacitors from one supply to the other supply. As the capacitors discharge, the voltage decreases and then the capacitors are charged with the opposite polarity.
Claims13
A circuit comprising:
- a driver circuit having an output and comprising an H-bridge operating from a differential voltage provided by a differential supply;
- and
- a boost circuit coupled to the driver circuit including a first and second capacitor driven by a respective capacitor driver and generating a differential write current and a differential output voltage across the driver circuit output, the differential output voltage being greater than the differential supply voltage.
Dependencies are inferred from the claim text.