International Rectifier Corporation

Smart Prong Technologies, Inc.

Hoa Nguyen

Dorin O Neacsu

A system may include a switch, a multiple stage voltage converter, and a regulation circuit. The switch may generate a pre-regulation signal based on an input signal. The multiple stage voltage converter may generate an output signal based on the input signal using a clock. The regulation circuit may generate a regulation signal based on the output signal and may generate a clock reference based on at least one of the pre-regulation signal and the regulation signal. The regulation circuit may generate the clock based on at least one of the pre-regulation signal, the regulation signal, and the clock reference and determine whether a voltage level of the regulation signal is within a range. If the voltage level of the regulation signal is within the range, the regulation circuit may generate a switch signal. The switch may adjust a voltage level of the pre-regulation signal based on the switch signal.

Electrical circuit for pre-regulation power management

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.

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Cerritos, CA, United States of America

Hoa Nguyen