Avalanche Photodiode Bias Circuit Shared Reference Voltage
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Solution Overview
Problem
The increasing size, power consumption, and cost of light receiving devices with multiple avalanche photodiodes arranged in parallel for wavelength multiplexing systems due to the need for multiple bias circuits and booster circuits.
Innovation Solution
A light receiving device with a plurality of avalanche photodiodes, level conversion units, and a control unit that generates control signals to adjust the bias voltage based on temperature, allowing for shared booster and level conversion circuits to optimize bias voltage for each photodiode, reducing the number of components and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple bias circuits are provided for each avalanche photodiode in wavelength multiplexing systems, then the receiving sensitivity of each photodiode can be optimized, but the device size increases
Solution Approach 1:
The patent merges multiple bias circuits into a single shared bias circuit that provides a common reference voltage to all avalanche photodiodes. The level conversion units then individually adjust this shared reference voltage to generate appropriate bias voltages for each photodiode, thereby reducing the number of components while maintaining optimized receiving sensitivity for each channel.
Solution Approach 2:
The shared reference voltage circuit serves multiple functions by providing a common voltage source for all avalanche photodiodes simultaneously. This universal voltage source is then individually converted by each level conversion unit to match the specific bias requirements of each photodiode, achieving multi-functionality with reduced component count.
2Reliability
If multiple bias circuits and booster circuits are provided for each avalanche photodiode, then the optimal bias voltage can be maintained for each photodiode, but the power consumption increases
Solution Approach 1:
The patent combines multiple booster circuits into a single shared booster circuit that generates a common reference voltage. This shared reference voltage is then individually adjusted by level conversion units for each photodiode, reducing the total power consumption while maintaining optimal bias voltage conditions for each avalanche photodiode.
3Reliability
If multiple bias circuits are provided for each avalanche photodiode, then the receiving performance can be optimized, but the device cost increases
Solution Approach 1:
The patent merges multiple independent bias circuits into a single shared reference voltage circuit, significantly reducing the number of components required. The level conversion units provide the necessary individualization at lower cost, thereby improving ease of manufacture and reducing device cost while maintaining optimized receiving performance for each photodiode.
4Area of stationary object
If a shared reference voltage circuit is used for multiple avalanche photodiodes, then the device size and power consumption are reduced, but the bias voltage optimization for each photodiode becomes challenging
Solution Approach 1:
The patent introduces level conversion units as intermediary components between the shared reference voltage circuit and each avalanche photodiode. These level conversion units individually adjust the common reference voltage to generate the specific bias voltages required by each photodiode, thereby maintaining bias voltage optimization ease while utilizing a compact shared voltage source.
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
The solution effectively suppresses the increase in device size and power consumption while maintaining optimal bias voltage for each avalanche photodiode, resulting in a cost-effective configuration.
Implementation Method 1
The APD is a photodiode in which a phenomenon called avalanche multiplication is utilized to increase light receiving sensitivity
Data Source
AI summary
A light receiving device that receives a light signal includes: a plurality of avalanche photodiodes, in each of which receiving sensitivity is set in accordance with a bias signal that is provided; a plurality of level conversion units provided in association with the avalanche photodiodes, each of the level conversion units being configured to convert a level of a reference voltage for obtaining the bias signal so as to generate the bias signal and being configured to provide the bias signal to corresponding one of the avalanche photodiodes; and a control unit that generates a first control signal corresponding to a temperature of the light receiving device, and controls a level conversion amount of each of the level conversion units by using the first control signal.