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:
Dec. 20, 2011
Filed:
Jun. 18, 2008
Gary Michael Hurtz, Shanghai, CN;
Trinh Khac Hue, Hung Yen Province, VN;
David J. Kunst, Cupertino, CA (US);
Gary Michael Hurtz, Shanghai, CN;
Trinh Khac Hue, Hung Yen Province, VN;
David J. Kunst, Cupertino, CA (US);
Active-Semi, Inc., , VG;
Abstract
A driver circuit (for example, in a switching power supply or in a Class-D switching amplifier) drives a gate of a switch during a transition with a low output impedance during an initial period and then for the remainder of the transition drives the gate with a midrange output impedance. The switch in turn switches current flow through an inductor. The driver circuit includes a 'Drive Node Voltage Dependent Impedance Circuit' (DNVDIC) that couples the gate to a supply voltage node. In one embodiment, there are two resistive current paths through the DNVDIC. A non-linear device in the first current path switches from having a small to a large impedance when a voltage drop across the device falls below a threshold voltage. The resulting increase in impedance of the first current path decreases voltage edge rates and reduces noise, whereas the low initial impedance reduces transition power losses.