Parallel Switch Control Circuitry for Power Electronics Footprint Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power electronics devices with single switches face challenges in achieving optimal turn-on times and package size due to parasitic capacitances and on-resistance, leading to larger control circuitry footprints and increased power consumption.
Innovation Solution
The use of a set of switches connected in parallel, where one switch has a lower on-resistance and higher parasitic capacitances, and another with lower parasitic capacitances but higher slew rate, allows for concurrent control signals to be delivered, reducing the overall control circuitry footprint and package size while maintaining similar performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single switch is used in power electronics devices, then the device structure is simple, but the control circuitry footprint increases and package size increases
Solution Approach 1:
The patent divides a single switch into multiple parallel switches (first switch and second switch). Each switch has different width-length ratios, allowing them to handle different current distributions. This segmentation reduces the control circuitry footprint while maintaining the required current handling capability, as each smaller switch requires less control circuitry area than a single large switch.
2Power
If a single switch with high current capability is used, then the current handling is sufficient, but the turn-on time increases due to higher parasitic capacitances
Solution Approach 1:
The patent segments the current handling function across multiple parallel switches with different width-length ratios. The first switch with lower parasitic capacitance turns on faster, while the second switch with higher current capability provides the necessary power handling. This segmentation allows the system to achieve both fast turn-on and sufficient current capability.
Solution Approach 2:
Each switch in the parallel configuration has different local characteristics (different width-length ratios). The first switch is optimized for fast switching with lower parasitic capacitance, while the second switch is optimized for current handling. This local quality differentiation allows each component to excel at its specific function while working together to meet overall system requirements.
3Volume of stationary object
If a single switch is used, then the device package size is compact, but the power consumption increases
Solution Approach 1:
The patent segments the power handling function across multiple switches with different characteristics. By using parallel switches with different width-length ratios, the system optimizes the distribution of power handling and switching losses. This segmentation allows for reduced overall power consumption while maintaining compact package size, as each switch operates in its optimal efficiency range.
4Device complexity
If a single switch is used, then the device is simple, but electromagnetic interference and thermal issues increase
Solution Approach 1:
The patent segments the switching function across multiple parallel switches. This segmentation distributes the electromagnetic interference generation across multiple smaller switching events rather than one large switching event. Similarly, thermal generation is distributed across multiple switches, improving heat dissipation. The increased device complexity is minimal compared to the significant reduction in EMI and thermal issues.
Data Source
AI summary
In some examples, a device includes a set of switches configured to deliver current to an output node of the device, wherein the set of switches includes a first switch including a first control terminal and a second switch including a second control terminal, wherein a width-length ratio of the second switch is larger than a width-length ratio of the first switch, and wherein the first switch is electrically connected in parallel with the second switch. The device further includes control circuitry configured to deliver a first control signal to the first control terminal and deliver a second control signal to the second control terminal concurrently with delivering the first control signal to the first control terminal.