LiDAR Light Module Layout for Short High-Energy Pulse Driving

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Solution Overview

Problem

Existing driver circuits for LiDAR devices suffer from parasitic inductances and capacitances that hinder the generation of high-energy, short-duration light pulses, and often require complex mechanical components for beam deflection.

Innovation Solution

A light module design with a carrier integrated circuit die, power transistor, laser diode, and charge storage component, optimized for minimal parasitic impedances, using bond wires and a control circuit to achieve rapid charging and switching, eliminating mechanical components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional driver circuits are used, then the circuit can operate with standard components, but parasitic inductances and capacitances hinder the generation of high-energy short-duration light pulses

Engineering Contradiction:
Improvepulse generation speedVSAvoidparasitic inductances and capacitances
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent combines the charge storage capacitor and the laser diode into a single integrated circuit die, eliminating the need for external connections and bond wires that would introduce parasitic inductances and capacitances. This integration allows the capacitor to be directly connected to the laser diode, enabling rapid charge transfer and high-energy pulse generation without the harmful effects of parasitic elements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent embeds the charge storage capacitor within the same integrated circuit die as the laser diode, creating a nested structure where the capacitor is positioned in close proximity to the laser diode. This nesting minimizes the distance between components, reducing parasitic inductances and capacitances while enabling fast charging and high-energy pulse output.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If mechanical mirrors are used for beam deflection, then the light can be directed in different directions, but the device complexity and presence of moving parts increase

Engineering Contradiction:
Improvebeam direction controlVSAvoidmechanical components
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical mirrors and moving parts with an integrated electronic control system. The laser diode array is directly integrated with control circuitry on the same die, allowing electronic steering and control of light beams without mechanical components. This substitution eliminates mechanical complexity while maintaining or enhancing beam direction control capabilities.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If separate mounting of components is used, then the components can be individually optimized, but the overall device size and connection complexity increase

Engineering Contradiction:
Improvecomponent optimizationVSAvoidmounting and connections
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the charge storage capacitor and laser diode into a single integrated circuit die, eliminating the need for separate mounting and external connections. This integration maintains the functional optimization of each component while removing the complexity associated with separate mounting, bonding, and wiring, resulting in a more reliable and compact device.

Inventive Principle:
Principle #5Merging (Combining)

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 design enables high-energy, short-duration light pulses without mechanical components, reducing electrical losses and interference, and allows for efficient, compact, and optimized imaging optics.

Implementation Method 1

a charge storage component (19, 20) with a bottom side having a first terminal block and a top side having a second terminal block, wherein the charge storage component is arranged with its first terminal block lying on the second conduction path terminal block of the transistor and these two terminal blocks are electrically connected to each other

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a light-emitting diode die (15, 16), in particular a light-emitting diode die, having a laser diode, with a bottom surface having a first terminal field and a top surface having a second terminal field

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Data Source

PatentEP4254011B1Light module and lidar apparatus having at least one light module of this type
Publication Date: 2026.03.11 ELMOS SEMICON AG
  • EP4254011B1 patent drawingFigure 1
  • EP4254011B1 patent drawingFigure 2
  • EP4254011B1 patent drawingFigure 3

AI summary

The light module comprises a carrier (TR) with a circuit die. On the top side (TRO) of the carrier (TR), a light-emitting diode die (D1D) and an associated charge storage component (LSBT) are electrically connected to the conduction path terminals (TAF1, TAF2) of a transistor (Tdis) via die-to-die bonds. The electrical connection between the two dies and the conduction path (LPF) of the transistor (Tdis) is as short as possible. On the top side of each of the two dies are terminals (DAF2, LAF2) connected to each other by a short bond wire (BD1). This discharge circuit is optimized to reduce parasitic inductances and ohmic resistances. The charge storage component (LSBT) is charged by a charging circuit (B1), which is electrically connected to the charge storage component (LSBT) via a second bond wire (BD2). The second bond wire (BD2) is longer than the first bond wire (BD1).The light module can be part of a LiDAR device, which may include a special optical system. The driver circuit for the transistor (Tdis) may also be designed in a special way.