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:
Oct. 01, 2002
Filed:
Oct. 23, 2001
Dorin O. Neacsu, Lexington, MA (US);
Hoa Huu Nguyen, Cerritos, CA (US);
International Rectifier Corporation, El Segundo, CA (US);
Abstract
An active resistance is controlled to modify a drive signal provided to a gated device such as an insulated gate bipolar transistor (IGBT). The active resistance is between an input lead that receives an input drive signal, such as from a conventional gate driver IC, and an output lead at which an output drive signal is provided to the device's gate. The active resistance is controlled in response to a feedback signal that includes information about the output drive signal, so that the output drive signal is a modified version of the input drive signal. To reduce di/dt and hence control EMI emission, the output drive signal can include turn-on and turn-off transitions where the input drive signal includes steps. A transition can, for example, include an interval during which the active resistance is greater than zero to reduce peak voltage, another interval during which the active resistance is approximately zero to allow a large gate current, and yet another interval during which the active resistance is greater than zero to limit gate current. The active resistance can be an active resistance device such as a MOSFET resistor, with its channel connected in series between the input and output leads. Similar circuitry can be provided for turn-on and for turn-off. The gate control circuit can be on an integrated circuit with a pin for connecting directly to an IGBT's gate.