The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 2007
Filed:
Sep. 30, 2004
Jeremy Kuehlwein, Woodbury, MN (US);
Raymond E. Barnett, Dallas, TX (US);
Jeremy Kuehlwein, Woodbury, MN (US);
Raymond E. Barnett, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A write driver circuit () uses a matching resistors (R, R) to match the impedance of the head () disposed between output nodes (OUTP, OUTN). Control circuitry (Q, Q, Q, Q, R, R, Rand R) maintains the voltage at reference voltage nodes (VREFP, REFN) at essentially the same voltage as its corresponding output node. The matching resistor is disposed between the reference voltage node and the output node along with a driver (), which may be implemented as an AB driver. Since the voltage between the reference node and the output node is generally zero, very little current is shunted by the matching resistors, and thus, there is very little power wasted by the matching resistors. In the preferred embodiment, the output transistors of the AB drivers are driven by switched current sources (Qand Q) to provide enhanced current to the bases of the output transistors on an as needed basis.