Laser Diode Pulse Driver Circuit for High-Peak ToF Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing time-of-flight (ToF) systems for applications like LiDAR face challenges in efficiently and effectively emitting high-power light pulses with precise control, particularly in achieving high peak output power and maintaining performance across varying frequencies.
Innovation Solution
A light emission system comprising a storage inductor, a storage capacitor, a switch, and a load of N laser diodes coupled in series, with a DC-blocking capacitor and a Schottky diode for AC-coupling and DC restoration, respectively. This configuration allows for efficient energy storage and release, enabling high-power light emission with control over pulse amplitude and duration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single laser diode is used to emit light, then the device complexity is low, but the peak output power is insufficient
Solution Approach 1:
The patent divides the light emission function into multiple laser diodes (first laser diode and second laser diode) that operate in parallel. Each laser diode can be independently controlled by separate drive circuits, allowing the system to achieve higher total output power while maintaining manageable complexity through modular architecture
Solution Approach 2:
The patent combines multiple laser diodes and their drive circuits into a unified light emission system. The parallel configuration merges the output of individual laser diodes to achieve higher peak power, while shared control logic and timing mechanisms manage the overall system complexity
2Power
If multiple laser diodes are used to increase peak output power, then the power increases, but the device complexity increases
Solution Approach 1:
The drive circuits are designed with multi-functionality to control multiple laser diodes. The control logic can selectively activate different combinations of laser diodes based on power requirements, and the circuits can operate in different modes (individual or combined operation) to provide universal control capability across varying power demands
Solution Approach 2:
The system uses periodic pulsing of laser diodes to achieve high peak power output. The drive circuits generate synchronized pulse signals that activate laser diodes in controlled sequences, allowing high power to be delivered in short bursts while maintaining lower average power consumption and heat generation
3Power
If high power is emitted continuously, then the power output is high, but the energy consumption increases
Solution Approach 1:
The system employs periodic pulsing operation where laser diodes are activated in short bursts rather than continuously. The drive circuits generate pulsed signals that deliver high peak power only when needed, with off periods allowing energy recovery and reducing overall energy consumption while maintaining high average power output capability
Solution Approach 2:
The control system prepares and pre-charges capacitor networks before laser diode activation. Energy is stored in advance in capacitors during the off period, then rapidly discharged to provide high peak power during the brief on period, eliminating the need for continuous high power consumption
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 system achieves high peak output power (equal to or higher than 1 kW) with pulse widths equal to or higher than 1 ns, and is capable of operating effectively across high-frequency applications, enhancing the performance of ToF systems in LiDAR and other optical technologies.
Implementation Method 1
a storage capacitor having a first capacitor terminal coupled to the first terminal of the storage inductor, and a second capacitor terminal coupled to a reference voltage node
Implementation Method 2
a storage inductor having a first inductor terminal coupled to a voltage source and a second inductor terminal; in the charge mode, the switch is closed, and the storage inductor is configured to store energy released from the storage capacitor. In the emission mode, the switch is open, and the storage inductor is configured to release current to drive the N laser diodes
Implementation Method 3
The N laser diodes include a first laser diode having a terminal coupled to the second inductor terminal; and an N-th laser diode having a terminal coupled to the reference voltage node
Implementation Method 4
N laser diodes coupled in series, where N is an integer larger than or equal to 2
Data Source
AI summary
A light emission system including a first sub-system. The first sub-system includes a storage inductor having a first inductor terminal coupled to a voltage source and a second inductor terminal; a storage capacitor having a first capacitor terminal coupled to the first terminal of the storage inductor, and a second capacitor terminal coupled to a reference voltage node; a switch having a control terminal coupled to a driver circuitry that sends a modulation signal to open or close the switch, a first channel terminal coupled to the second inductor terminal, and a second channel terminal coupled to the reference voltage node; and a load having N laser diodes coupled in series, where the N laser diodes include a first laser diode having a terminal coupled to the second inductor terminal, and an N-th laser diode having a terminal coupled to the reference voltage node.