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:
Aug. 12, 1997
Filed:
Jun. 07, 1995
Carl T Nelson, San Jose, CA (US);
Robert Essaff, Fremont, CA (US);
Linear Technology Corporation, Milpitas, CA (US);
Abstract
Circuits and methods are provide for improving the turn-off switching speed of a high-speed integrated circuit, bipolar switching regulator. The regulator runs at megahertz frequencies, yet is efficient as previously available bipolar integrated circuit switching regulators operating at much lower frequencies. The turn-off circuitry increases the speed at which the switch turns off by momentarily providing additional current to boost the base discharge current during the on-to-off transition period of the switch. In a preferred embodiment, the circuitry includes a capacitor for storing a charge, a resistor for limiting the amount of additional current provided, and a diode for delivering the additional current to the base of an NPN transistor, the collector of which is coupled to the switch's base, for boosting that transistors collector current and the switch's base discharge current. The diode then blocks current during the off-to-on transition period of the switch. Thus, the turn-off circuitry operates on an AC basis and only when the switch is turning off.