GaN Driving Circuit Parasitic Interference Elimination
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Solution Overview
Problem
Conventional power circuits face interference from parasitic effects in the switch node due to the inductor, which affects the boost voltage when charging the boost capacitor, necessitating a solution to eliminate these effects for reliable operation.
Innovation Solution
A driving circuit with a GaN regulator that includes differential amplifiers, a pass element, and feedback voltage dividers, along with clamp circuits and a charge pump, is implemented to manage the supply voltage and control signals effectively, ensuring the high-side transistor is fully turned on without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional charge pump with boost capacitor and boost diode is used to boost supply voltage, then the high-side transistor can be fully turned on, but parasitic effects from the inductor interfere with the boost voltage during capacitor charging
Solution Approach 1:
The patent extracts the harmful inductor from the charge pump circuit and replaces it with a resistor. This removal eliminates the parasitic effects (negative voltage spikes) that the inductor generated during capacitor charging, while the resistor provides the necessary current limiting function without the harmful inductive properties.
Solution Approach 2:
The patent changes the fundamental parameter of the energy storage element from inductive (inductor) to resistive (resistor). This parameter change transforms the circuit behavior from one that generates parasitic voltage spikes to one that provides stable voltage boosting without interference, fundamentally altering the electrical characteristics to eliminate the harmful effects.
2Object-affected harmful factors
If a resistor is used instead of inductor in the charge pump, then parasitic effects are eliminated, but the circuit structure and component selection must be modified
Solution Approach 1:
The patent applies parameter change by substituting the inductor with a resistor, fundamentally changing the electrical parameter from inductive to resistive. This simple parameter substitution eliminates parasitic effects while maintaining the charge pump's core functionality, demonstrating that complex problems can sometimes be solved through straightforward parameter modifications rather than complex circuit redesigns.
Data Source
AI summary
A regulator converting an input voltage into a supply voltage includes a first differential amplifier, a second differential amplifier, a pass element, and a feedback voltage divider. The first differential amplifier includes a reference voltage with a feedback voltage to generate a first output voltage and a first inverse output voltage. The second differential amplifier compares the first output voltage and the first inverse output voltage to generate a second output voltage. The pass element passes an output current from the input voltage to the supply voltage according to the second output voltage. The feedback voltage divider divides the supply voltage by a feedback factor to generate the feedback voltage.