Alpha and Omega Semiconductor (cayman) Ltd.

Alpha Omega Semiconductor Inc.

Wonjin Cho

Bum-Seok Suh

Son Tran

Zhiqiang Niu

Jun Lu

James Rachana Bou

Cheow Khoon Oh

A method of generating a gate drive signal for driving a control terminal of a power switch includes detecting a system input signal; determining a signal pulse of the system input signal being a first signal pulse following a power up event, or following an idle period, or following removal of a fault condition; and in response, generating a soft gate drive signal to drive the control terminal of the power switch to softly turn on the power switch. In another embodiment, the method includes determining a duration of the on period of the system input signal exceeding a maximum on duration and in response, disabling the gate drive signal to turn off the power switch; and determining a deassertion transition of the system input signal and in response, blocking the system input signal from the gate drive signal for a minimum off duration.

Intelligent power module control method for resonant converter

A controller for driving a power switch incorporates a hard turn-on disable circuit to prevent the power switch from turning on when the power switch is sustaining a high voltage value. The hard turn-on disable circuit includes a hard turn-on detection circuit and a protection logic circuit. The hard turn-on disable circuit is configured to block or to pass the system input signal to the normal gate drive circuit of the power switch depending on the detection indicator signal. In particular, the protection logic circuit blocks the system input signal Vin response to a high voltage detection so that the power switch ignores the system input signal V, which may be erroneous, and the power switch is prevented from undesirable hard switching.

Hard switching disable for switching power device

An intelligent power module includes a power switch, a freewheeling device, and a controller circuit incorporating a gate drive circuit and one or more power switch protection circuits. In one embodiment, the power switch is an insulated gate bipolar transistor (IGBT) device, the freewheeling device is a PN junction diode, and the controller circuit is implemented as a semiconductor integrated circuit (IC). The power module implements protection functions for the power switching device where the protection circuits are formed on the controller circuit IC and co-packaged with the power switch. In some embodiments, the control circuit in the power module includes an active soft-start circuit which is activated to realize soft-start of the power switch. In other embodiments, the control circuit in the power module includes an active turn-on pulse control circuit to detect for abnormal system input signal pulse events and block system undesired input pulses.

Intelligent power modules for resonant converters

A controller for driving a power switch incorporates a protection circuit to protect the power switch from fault conditions, such as over-voltage conditions or power surge events. The protection circuit includes a fault detection circuit and a protection gate drive circuit. The fault detection circuit is configured to monitor the voltage across the power switch and to generate a fault detection indicator signal and the protection gate drive circuit is configured to generate a gate drive signal to turn on the power switch in response to a detected fault condition. In particular, the protection gate drive circuit generates a gate drive signal that has a slow assertion transition and is clamped at a given gate voltage value. In this manner, the protection circuit implements active clamping of the gate terminal of the power switch and safe handling of the power switch during over-voltage events.

Active clamp overvoltage protection for switching power device

An intelligent power module (IPM) has a first, second, third and fourth die paddles, a first, second, third, fourth, fifth and sixth metal-oxide-semiconductor field-effect transistors (MOSFETs), a tie bar, a metal slug, a plurality of spacers, a plurality of leads and a molding encapsulation. The molding encapsulation encloses the first, second, third and fourth die paddles, the first, second, third, fourth, fifth and sixth MOSFETs, the tie bar and the plurality of spacers. A bottom surface of the metal slug is exposed from the molding encapsulation. A process for fabricating the IPM comprises preparing the first, second, third and fourth die paddles, the first, second, third, fourth, fifth and sixth MOSFETs, the tie bar, the plurality of leads, the metal slug and the plurality of spacers and applying a molding process to form the molding encapsulation.

Molded intelligent power module and method of making the same

An intelligent power module (IPM) has a first, second, third and fourth die paddles, a first, second, third, fourth, fifth and sixth metal-oxide-semiconductor field-effect transistors (MOSFETs), a tie bar, an IC, a plurality of leads and a molding encapsulation. The first MOSFET is attached to the first die paddle. The second MOSFET is attached to the second die paddle. The third MOSFET is attached to the third die paddle. The fourth, fifth and sixth MOSFETs are attached to the fourth die paddle. The IC is attached to the tie bar. The molding encapsulation encloses the first, second, third and fourth die paddles, the first, second, third, fourth, fifth and sixth MOSFETs, the tie bar and the IC. The IPM is a small-outline package. It reduces system design time and improves reliability. The IC includes boost diodes. It reduces a package size of the IPM.

Molded intelligent power module

A power module has a lead frame, a first power chip, a second power chip, a plurality of single in-line leads, a gate drive and protection integrated circuit (IC), a plurality of bonding wires and a molding encapsulation. The first and second power chips are attached to a top surface of the lead frame. The plurality of single in-line leads has a high voltage power lead, a low voltage power lead and a plurality of signal control leads. The low voltage power lead has a lead portion and an extension portion. The gate drive and protection IC is attached to the extension portion of the low voltage power lead. The molding encapsulation encloses the first and second power chips, the extension portion of the low voltage power lead, the gate drive and protection IC, the plurality of bonding wires and at least a majority portion of the lead frame.

Molded power module having single in-line leads

An intelligent power module (IPM) has a first, second, third and fourth die paddles, a first, second, third, fourth, fifth and sixth transistors, a tie bar, a low voltage IC, a high voltage IC, a first, second and third boost diodes, a plurality of leads and a molding encapsulation. The first transistor is attached to the first die paddle. The second transistor is attached to the second die paddle. The third transistor is attached to the third die paddle. The fourth, fifth and sixth transistor s are attached to the fourth die paddle. The low and high voltage ICs are attached to the tie bar. The molding encapsulation encloses the first, second, third and fourth die paddles, the first, second, third, fourth, fifth and sixth transistors, the tie bar, the low and high voltage ICs, and the first, second and third boost diodes. The IPM has a reduced top surface area and a reduced number of leads compared to a conventional IPM.

Growing community of inventors

Suwon-si, South Korea

Wonjin Cho