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US 2022/0029383 A1Published application
Light source system
AssigneeAnalog Devices International Unlimited Company
InventorsJonathan Ephraim David Hurwitz, Eoin E. English
Life of this patent
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Abstract
The present disclosure relates to light source driving systems, for example laser driving systems. The systems are configured to include a very low inductance current loop for driving an initial part of the current drive signal to turn on the light source. By implementing the system to have a very low inductance current loop, a very fast turn on time may be achieved for the light source, which can be particularly useful for Time of Flight systems that require a very quick turn-on response from the light source.
Claims20
A light source system comprising:
- a substrate;
- a light source mounted on a surface of the substrate, wherein the light source comprises:
- an upper surface having an upper terminal;
- and
- a mounting surface conductively fixed to the surface of the substrate and having a lower terminal, the light source being configured to be turned on by current flowing between the upper terminal and the lower terminal,
- a vertical capacitor for supplying a first part of the current to drive the light source, wherein the vertical capacitor comprises:
- an upper surface comprising an upper terminal to a first plate of the vertical capacitor, wherein the upper terminal of the vertical capacitor is electrically coupled to the upper terminal light source;
- and
- a mounting surface conductively fixed to the surface of the substrate and comprising a lower terminal to a second plate of the vertical capacitor;
- and
- a current driver mounted on the surface of the substrate and coupled to the light source and the vertical capacitor for controlling the flow of current from the vertical capacitor to the light source in order to control operation of the light source,
- wherein the substrate comprises a voltage terminal that is electrically coupled to the vertical capacitor for supplying a second part of the current required to drive the light source.
9 more elements
A light source system comprising:
- a driver IC comprising a current driver;
- a light source mounted on a surface of the driver IC, wherein the light source comprises:
- a first terminal;
- and
- a second terminal on a mounting surface of the light source, the second terminal of the light source being conductively bonded to a first terminal of the current driver on the surface of the driver IC;
- and
- a capacitor mounted on the surface of the driver IC, wherein the capacitor comprises:
- a first terminal to a first plate of the capacitor, the first terminal being conductively coupled to a supply voltage and to the first terminal of the light source such that when the light source is on current flows from the first plate of the capacitor to the first terminal of the light source;
- and
- a second terminal to a second plate of the capacitor, the second terminal of the capacitor being on a mounting surface of the capacitor and conductively bonded to a second terminal of the current driver on the surface of the driver IC such that when the light source is on current flows from the second terminal of the light source to the second plate of the capacitor via the current driver.
7 more elements
A laser driving circuit comprising:
- a laser;
- a first capacitor coupled to the laser for supplying current to drive the laser, wherein the first capacitor has a first capacitance;
- a second capacitor coupled to the laser for supplying current to drive the laser, wherein the second capacitor has a second capacitance that is larger than the first capacitance;
- a current driver coupled to the laser, the first capacitor and the second capacitor for controlling a flow of current between the laser and the first and second capacitors,
- wherein the laser, current driver and first capacitor together form a first current circuit, and
- wherein the laser, current driver and second capacitor together form a second current circuit, and
- wherein an inductance of the first current circuit is relatively lower than an inductance of the second current circuit.
4 more elements
Dependencies are inferred from the claim text.