High-Side Driver Circuit With Level Shifting for Smaller Chip Area
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional high-side driver circuits require medium breakdown voltage devices due to high potential separation, leading to larger chip areas, even when configured with low breakdown voltage MOSFETs.
Innovation Solution
A high-side driver circuit is designed with a constant voltage circuit generating a third potential lower than the power supply potential, allowing a low breakdown voltage MOSFET to be used in the logic circuit, and a level shift circuit shifts the reference potential to enable efficient operation with a low breakdown voltage device, reducing chip area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional self-separation type HVIC is used with high potential separation, then the circuit can operate with high voltage, but the chip area increases due to requiring medium breakdown voltage devices
Solution Approach 1:
The patent applies local quality by creating different potential reference regions within the high-side circuit. The logic circuit operates with a third potential (VL) as reference, while the driver circuit operates with a second potential (VB) as reference. This localized potential differentiation allows the logic circuit to use low breakdown voltage devices while maintaining high voltage operation capability in the driver circuit, thereby reducing overall chip area.
Solution Approach 2:
The patent changes the potential reference parameter from a single high voltage reference to multiple hierarchical references (first potential VH > second potential VB > third potential VL). The constant voltage circuit generates the third potential VL lower than VB, enabling the logic circuit to operate with low breakdown voltage devices. This parameter transformation resolves the contradiction by allowing high voltage operation where needed while using lower voltage devices in other regions.
2Reliability
If medium breakdown voltage devices are used in the high-side circuit, then high voltage operation is enabled, but the device area and chip complexity increase
Solution Approach 1:
The patent segments the high-side circuit into functionally independent blocks with different potential references: a constant voltage circuit that generates VL, a logic circuit operating with VL as reference, a level shift circuit that converts between VL and VB, and a driver circuit operating with VB as reference. This segmentation allows each block to use appropriately sized devices, reducing overall device complexity while maintaining high voltage operation capability.
Solution Approach 2:
The level shift circuit acts as an intermediary between the logic circuit (operating at VL reference) and the driver circuit (operating at VB reference). This intermediary component enables signal level conversion without requiring the entire high-side circuit to use medium breakdown voltage devices, thereby reducing device complexity while preserving high voltage operation capability.
Data Source
AI summary
An object of the present invention is to reduce a chip area of the high-side driver circuit. A high-side driver circuit of the present invention is a high-side driver circuit in which a first potential is set as a power supply potential, which includes a constant voltage circuit configured to operate with a second potential as a reference potential, and generate, from the first potential, a third potential which is lower than the first potential and higher than the second potential, a logic circuit configured to operate with the third potential as a reference potential, a level shift circuit configured to shift the reference potential of the output signal of the logic circuit from the third potential to the second potential, and a driver circuit in which the second potential is set as a reference potential, and configured to drive a switching element by the output signal.