On-board microelectromechanical system (MEMS) sensing device for power semiconductors
AssigneeRockwell Automation Technologies, Inc.
InventorsRichard D. Harris, Robert J. Kretschmann
Life of this patent
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Abstract
An on-board micro-electromechanical (MEMS) isolator is provided on board a power semiconductor device for measuring voltage, current, or both. In particular, the power semiconductor may comprise a plurality of transistors connected in parallel, such that a MEMS isolator connected in parallel with one of the transistors measures voltage across the semiconductor. A MEMS isolator may further be connected in series with the transistors to measure current flow thereacross. A compensation circuitry may be provided to receive the current output from the isolator, and determine total current flow through the power semiconductor.
Claims25
An on-board micro-electromechanical (MEMS) electrical device for sensing an electrical property of a power transistor having a collector, a base, and an emitter, the device comprising:
- a substrate;
- an element supported by the substrate and movable between a first and second position;
- an actuator attached to the element to receive an input electrical signal from the transistor that exerts a force dependent on the input electrical signal urging the element toward the second position;
- a bias structure attached to the element to exert a predetermined opposite force on the element urging the element towards the first position;
- and
- a sensor attached to the second portion of the element to provide an output electrical signal indicating movement of the of the element between the first position and the second position.
A power semiconductor device having on-board sensing capabilities, the device comprising:
- a plurality of power transistors electrically connected in parallel, wherein one of the power transistors is supported by a first substrate, and has a collector, a base, and an emitter;
- a first MEMS device disposed on a second substrate and in electrical communication with said one of the power transistors, said MEMS sensor including:
- i. an element supported by the second substrate for movement between a first and second position with respect to the substrate;
- ii. an actuator attached to the element to receive an electrical input signal from said one of the power transistors;
- iii. a bias structure attached to the element to exert a predetermined opposite force on the element urging the element toward the first position;
- and
- iv. a sensor attached to the second portion of the element to provide an output electrical signal indicating movement of the element between the first position and the second position;
- wherein an input signal of above a predetermined threshold overcomes the opposite force to cause the element to move rapidly from the first to the second position to produce the output electrical signal electrically isolated from the input electrical signal.
Dependencies are inferred from the claim text.