GaN Driving Circuit Precharging for Faster HEMT Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The lack of P-type GaN-based HEMTs in the GaN process hinders the development of GaN-based driving circuits, as designers struggle to create effective driving circuits without these essential components.
Innovation Solution
The proposed solution involves a driving circuit configuration that utilizes enhancement-mode N-type HEMTs and depletion-mode N-type HEMTs, eliminating the need for P-type HEMTs by employing balanced precharging circuitry to generate high boost driving voltages, thereby enabling efficient operation of GaN-based HEMTs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If P-type GaN-based HEMTs are used in the driving circuit, then the driving capability and switching performance are improved, but the manufacturing complexity and cost increase due to the lack of mature P-type GaN process
Solution Approach 1:
The patent extracts and eliminates the requirement for P-type HEMTs from the driving circuit by using a fully N-type HEMT configuration. The circuit achieves the necessary driving functions using only N-type enhancement-mode and depletion-mode HEMTs, removing the manufacturing complexity associated with P-type GaN processes while maintaining driving capability.
Solution Approach 2:
The patent changes the device type parameters from including both P-type and N-type HEMTs to using only N-type HEMTs with different modes (enhancement-mode and depletion-mode). This parameter change in device selection resolves the manufacturing complexity issue while preserving the required driving performance through alternative device configurations.
2Productivity
If conventional driving circuits are used without precharging circuitry, then the circuit design is simpler, but the voltage push-up duration is prolonged and switching frequency is reduced
Solution Approach 1:
The patent applies preliminary action by incorporating precharging circuitry that prepares the voltage levels before the main switching operation. The precharging circuitry pre-charges the gate voltages of the HEMTs, reducing the voltage push-up duration and enabling faster switching frequencies, thus improving productivity through advance preparation.
Solution Approach 2:
The patent segments the voltage generation process into distinct stages: a precharging stage that generates initial voltage and a main driving stage that provides the final drive signal. This segmentation allows the circuit to optimize each stage independently, reducing overall switching time and increasing frequency capability despite increased circuit complexity.
Data Source
AI summary
A driving circuit includes a driving stage, and a first subcircuit. The driving stage includes a first driving device and a second driving device configured to drive a power device. The first subcircuit is electrically connected to the driving stage. The first subcircuit includes a first precharge circuit and a first predriving circuit. The first predriving circuit is electrically connected to the first precharge circuit and the first driving device. The first precharge circuit is configured to, in response to an input signal of the driving circuit having a first signal level, generate a first precharging voltage. The first precharge circuit is further configured to, in response to the input signal having a second signal level different from the first signal level, fully turn on, based on the first precharging voltage, a first predriving device in the first predriving circuit to drive the first driving device.