Avalanche Photodiode Quenching Circuit Isolation
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Solution Overview
Problem
In photo-detection devices sharing a DC bias power source with other elements or devices, the quench signal feedback can cause abnormal operation or changes in detection results due to potential changes affecting other elements or devices.
Innovation Solution
The photo-detection device incorporates a quench signal feedback mechanism that uses a switch, such as a transistor, to control the reverse bias applied to the avalanche photodiode, ensuring the quench action does not significantly alter the potential at the shared power source, thereby minimizing interference with other elements or devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the quench signal is superimposed on the DC bias and fed back to the avalanche photodiode, then high-speed quenching is achieved, but the potential at other elements or the bias potential at other photo-detection devices sharing the same DC bias power source changes, causing abnormal operation or detection errors
Solution Approach 1:
The patent divides the bias power supply into separate independent power sources for different elements or photo-detection devices. Instead of sharing a common DC bias power source, each element receives its own dedicated bias voltage, preventing potential changes in one element from affecting others during quenching operations.
Solution Approach 2:
The patent introduces a bias voltage adjustment mechanism that acts as an intermediary between the quench signal and the bias power source. When a quench signal is generated, the system adjusts the bias voltage of affected elements to maintain stable operation, preventing direct potential changes from propagating to other elements.
2Productivity
If the quench signal is fed back to the DC bias in a photo-detection device, then avalanche current is forcibly stopped, but the bias potential changes affect other photo-detection devices sharing the same power source, leading to no photo-detection or abnormal operation
Solution Approach 1:
The patent implements separate bias power sources for each photo-detection device or element, eliminating the interference pathway. When one device performs quenching, its independent power source prevents bias potential changes from affecting other devices, ensuring continuous accurate photo-detection across all elements.
Solution Approach 2:
The patent employs a feedback mechanism that monitors bias potential changes and dynamically adjusts the bias voltage in response to quenching events. This feedback control compensates for potential fluctuations, maintaining stable operating conditions for photo-detection even when quenching occurs in shared power source scenarios.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the impact of quench actions on other elements or devices, maintaining accurate photo-detection results and preventing abnormal operations even under high illuminance conditions.
Implementation Method 1
Photo-detection device that performs photoelectric conversion
Implementation Method 2
avalanche photodiode having an active-quenching mechanism that forcibly stops avalanche current
Data Source
AI summary
A photo-detection device includes an APD, a current detecting unit to which a signal via a first terminal of the APD is input, a load element connected to a node between the APD and the current detecting unit, a quench signal generating unit to which a signal from the current detecting unit is input and which outputs a quench signal, and a switch connected to a second terminal of the APD and a first wiring line to which first potential is supplied. The node is connected via the load element to a second wiring line to which second potential different from the first potential is supplied, and the quench signal generating unit generates a one-shot pulse signal as the quench signal based on the signal from the current detecting unit and causes the quench signal to be input to the switch.