Power Module Shunt Layout for Accurate Current Sensing
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Solution Overview
Problem
In power modules with shunt resistors, accurately detecting current is challenging due to the influence of parasitic inductive components, which affect the detection accuracy of the current flowing through the shunt resistor.
Innovation Solution
The power module design incorporates a conductive pattern arrangement that forms a U-shaped or three-dimensional current path to cancel magnetic flux, using reverse currents to minimize the parasitic inductive component, thereby improving the detection accuracy of the current flowing through the shunt resistor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a shunt resistor is inserted into the power loop to detect current, then current detection capability is improved, but parasitic inductive components increase which deteriorates detection accuracy
Solution Approach 1:
The patent applies this principle by using the magnetic flux generated by the shunt resistor current to induce a compensating current in the adjacent conductive pattern. The harmful parasitic inductive component is converted into a beneficial effect where the induced current creates opposing magnetic flux that cancels out the parasitic inductance, thereby improving current detection accuracy.
Solution Approach 2:
The conductive pattern serves as an intermediary element between the shunt resistor and the detection system. It mediates the magnetic flux interaction by being positioned adjacent to the shunt resistor, allowing magnetic coupling to occur. This intermediary structure enables the conversion of magnetic flux into a compensating current that reduces the harmful parasitic inductive effects.
2Reliability
If the shunt resistor resistance value is reduced to minimize circuit influence, then circuit disturbance is reduced, but detection sensitivity may be affected
Solution Approach 1:
By reducing the shunt resistor resistance value, the patent minimizes circuit disturbance and power loss while the magnetic flux coupling mechanism converts the potentially reduced detection signal into a compensated measurement. The adjacent conductive pattern captures the magnetic flux from the low-resistance shunt resistor and generates an induced current that maintains detection sensitivity despite the lower resistance value.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances the detection accuracy of the current flowing through the shunt resistor, allowing for precise switching control of power devices and efficient conversion of DC power to AC power.
Implementation Method 1
a current in a direction opposite to that of the current flowing through the shunt resistor is formed, thereby the magnetic flux by the shunt resistor may be canceled by the magnetic flux by the current
Data Source
AI summary
According to one embodiment, a power module including a power device, a first conductive pattern, a shunt resistor element, and a second conductive pattern is provided. One end of the first conductive pattern is connected to the power device. The first conductive pattern extends from the power device in at least a first direction. One end of the shunt resistor element in the first direction is connected to the other end of the first conductive pattern. The second conductive pattern is connected to the other end of the shunt resistor element. The second conductive pattern includes a portion. The portion extends in the first direction along the shunt resistor element and the first conductive pattern from a position separated from the shunt resistor element in the second direction. The second direction intersects the first direction.