Surge Protection Circuit with Segmented Parallel Branches

The protection circuit divides the voltage protection function into multiple stages, each handling a specific voltage range. Instead of using one high-voltage transistor or series connection, the circuit segments the protection into multiple parallel branches with different trigger voltages, where each branch independently handles overvoltage events within its specific range, avoiding the need for series connections and reducing total series resistance.

Each protection branch is designed with specific local characteristics - different trigger voltages and current limits - to handle specific overvoltage scenarios. The first branch triggers at a lower voltage threshold while the second branch triggers at a higher voltage threshold, allowing each component to operate optimally within its designed voltage range rather than requiring all components to handle the full voltage range.

The protection function is segmented into multiple independent parallel branches rather than series connections. Each branch has its own transistor with controlled parasitic capacitance, and the branches operate independently. This segmentation eliminates the cumulative parasitic capacitance problem of series connections while maintaining the ability to withstand high overvoltages through voltage distribution across parallel paths.

The protection circuit is designed with pre-configured trigger thresholds and pre-charged capacitors ready to activate immediately upon overvoltage detection. The balancing circuits and reference voltage generators are continuously monitoring and prepared, allowing the protection mechanism to respond instantly without the delay of charging parasitic capacitances that would occur in series-connected transistor configurations.

The invention extracts the energy dissipation function from the primary protection path by using parallel branches that divert excess voltage away from the main circuit. Instead of relying on varistors to absorb all energy, the circuit extracts harmful voltage excursions through controlled conduction in parallel branches, significantly reducing the energy burden on any single component and extending overall system lifetime.

The protection circuit uses multiple transistors configured in parallel branches with different trigger voltages, where each transistor is designed to handle specific overvoltage events. This approach replaces expensive, limited-life varistors with more durable transistors that can be selectively activated. The system accepts that individual transistors may need replacement but designs the overall system for extended operational life through redundancy and distributed stress.

The invention merges the voltage detection, current limiting, and protection functions into a unified parallel-branch architecture. Instead of separate varistor and transistor circuits that must coordinate, the design combines these functions into integrated branches where reference voltage generators, balancing circuits, and transistors work together in each branch independently. This merging eliminates the coordination complexity of mixed transistor-varistor systems while maintaining high voltage withstand capability.

Each parallel branch is designed as a multi-functional unit that simultaneously performs voltage detection, current limiting, and overvoltage diversion. The balancing circuits and reference voltage generators enable each branch to independently sense voltage conditions, regulate current flow, and activate protection when needed. This universal design eliminates the need for separate specialized components for each function, reducing overall circuit complexity.