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US-20260128800-A1 - LOW POWER MICRO-LED DRIVER FOR HIGH BANDWIDTH SHORT DISTANCE COMMUNICATION

US20260128800A1US 20260128800 A1US20260128800 A1US 20260128800A1US-20260128800-A1

Abstract

A driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuitry comprising: at least one inverter; a first capacitance; a resistor coupled to ground; a fast switch comprising at least one first transistor; and a slow switch comprising at least one second transistor; whereby at least one of a rising time, a peaking effect, and LED power is increased.

Inventors

  • Morteza Nabavi
  • Hossein FARIBORZI
  • Abdolreza Nabavi
  • Mohsen ASAD

Assignees

  • HYPERLUME INC.

Dates

Publication Date
20260507
Application Date
20250216

Claims (20)

  1. 1 . A driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuitry comprising: at least two inverters; an RC current shaping circuit comprising a first capacitance and a resistor coupled to ground; a first switch; and a second switch; whereby at least one of a rising time, a peaking effect, and the micro-LED's power is increased.
  2. 2 . A driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuitry comprising: at least one inverter; a first capacitance; a first switch; a booster comprising a second capacitance and a second switch to increase a current and a high voltage of the first switch, thereby improving the power of the first switch to increase the rise time and the peaking effect.
  3. 3 . The driver circuit of claim 2 , wherein the second switch comprises a p-type metal-oxide-semiconductor.
  4. 4 . A driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuit comprising: at least one first inverter; a first capacitance; a first switch; at least two second inverters, whereby a floating negative voltage is applied between the micro-LED and the first switch.
  5. 5 . The driver circuit of claim 4 , further comprising a booster circuit comprising at least one transistor and a second capacitance, wherein the booster circuit improves a peaking of a modulated current to the micro-LED.
  6. 6 . The driver circuit of claim 5 , wherein the at least one transistor comprises a p-type metal-oxide-semiconductor.
  7. 7 . The driver circuit of claim 6 , further comprising: a shunt transistor to improve a sweep-out effect of a modulated current in the micro-LED's active region when an electrical pulse is turned on and off; and wherein the booster circuit comprises an inverter.
  8. 8 . The driver circuit of claim 5 , wherein the shunt transistor improves the micro-LED's modulation rate.
  9. 9 . The driver circuit of claim 1 , wherein a negative voltage is applied between a cathode of the micro-LED and the first switch, and wherein a Vg s and V ds voltage between a gate/drain and a source of the at least one first transistor is maintained within a predetermined range.
  10. 10 . A driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuit comprising: at least one first inverter; a first switch comprising at least one first transistor; a shunt transistor to improve a sweep-out effect of a modulated current in the micro-LED's active region when an electrical pulse is turned on and off.
  11. 11 . The driver circuit of claim 10 , wherein the shunt transistor improves the micro-LED's sweeping out.
  12. 12 . The driver circuit of claim 10 or claim 11 , wherein a negative voltage is applied between a cathode of the micro-LED and the first switch, and wherein a V gs and V ds voltage between a gate/drain and a source of the first switch is maintained within a predetermined range.
  13. 13 . A method comprising the steps of: generating, using driving circuitry, a drive current to supply to a micro light-emitting diode (micro-LED); modulating the drive current; increasing a rising time and a peaking effect of the modulated drive current.
  14. 14 . The method of claim 13 , further comprising improve a sweep-out effect of a modulated current in the micro-LED's active region when an electrical pulse is turned on and off.
  15. 15 . The method of claim 13 , further comprising a step of applying a negative voltage is between a cathode of the micro-LED and a switch comprising at least one first transistor.
  16. 16 . The method of claim 15 , further comprising a step of maintaining a V gs and V ds voltage between a gate/drain and a source of the at least one first transistor within a predetermined range.
  17. 17 . The method of claim 15 , further comprising a step of, with a plurality of inverters, to improve the rising time and the peaking effect.
  18. 18 . The method of claim 13 , further comprising a step of, with a shunt transistor, improving the micro-LED's modulation rate and improving a sweep-out effect of a modulated current in the micro-LED's active region when an electrical pulse is turned on and off.
  19. 19 . The method of claim 13 , further comprising a step of, with a booster circuit comprising at least one transistor and a second capacitance, improves a peaking of a modulated current to the micro-LED.
  20. 20 . The method of claim 13 , further wherein the at least one first transistor comprises a p-type metal-oxide-semiconductor.

Description

FIELD Aspects of the disclosure relate to methods and systems for optical communication systems, and more particularly to optical communications over short distances using micro-LEDs. BACKGROUND Lasers tend to dominate optical communications for long distance applications, given their high-speed characteristics and narrow linewidth at the cost of high-power consumption. However, these benefits are not necessarily required for optical communications for very short distances such as chip to chip communications. In addition, due to the high bandwidth required for artificial intelligence (AI application), low power consumptions are needed. As such, chip to chip communications based on micro-LEDs is a suitable candidate for low power communication. SUMMARY In one of its aspects, a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuitry comprising: at least two inverters;an RC current shaping circuit comprising a first capacitance and a resistor coupled to ground;a first switch; anda second switch;whereby at least one of a rising time, a peaking effect, and the micro-LED's power is increased. In another aspect, a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuit comprising: at least one first inverter;a first capacitance;a first switch;at least two second inverters, whereby a floating negative voltage is applied between the micro-LED and the first switch. In another aspect, a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), the driver circuit comprising: at least one first inverter;a first switch comprising at least one first transistor;a shunt transistor to improve a sweep-out effect of a modulated current in the micro-LED's active region when an electrical pulse is turned on and off. In another aspect, a method comprising the steps of: generating, using driving circuitry, a drive current to supply to a micro light-emitting diode (micro-LED);modulating the drive current;increasing a rising time and a peaking effect of the modulated drive current. In another aspect, there is provided a driver circuit and equalizer for peaking and sweep out of the signals driving LEDs, such as a micro-LED. In one example, the micro-LED operates at a different supply voltage than the rest of the circuit. The methods and systems described herein address certain limitations associated with micro-LEDs, such as low modulation bandwidth. BRIEF DESCRIPTION OF THE DRAWINGS Several exemplary embodiments of the present disclosure will now be described, by way of example only, with reference to the appended drawings in which: FIG. 1a shows a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), in one example; FIG. 1b shows the difference in the modulation signal between a driver circuit of FIG. 1a with assist circuitry and without assist circuitry (simple); FIG. 2a shows a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), comprising a booster circuit; FIG. 2b shows an on-off keying (OOK) modulation signal to the micro-LED generated by the driver circuit of FIG. 2a; FIG. 2c shows the difference in the modulating signal between a driver circuit of FIG. 2a with boosting and without boosting (simple); FIG. 3a shows a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), comprising additional inverters; FIG. 3b shows an on-off keying (OOK) modulation signal to the micro-LED generated by the driver circuit of FIG. 3a; FIG. 4a shows a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), comprising a shunt transistor; FIG. 4b shows an on-off keying (OOK) modulation signal to the micro-LED generated by the driver circuit of FIG. 4a without the shunt transistor; FIG. 4c shows the modulation signal without a shunt transistor (simple) and with a shunt transistor; FIG. 5a shows a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), comprising a booster circuit and additional inverters; FIG. 5b shows a comparison of the peaking current of a driver circuit of FIG. 5a with a booster circuit and without a booster circuit (simple, no peaking); FIG. 6a shows a driver circuit for supplying and regulating power to a micro light-emitting diode (micro-LED), comprising a booster circuit and additional inverters, and a shunt transistor; FIG. 6b shows a comparison of the peaking current with a booster and without a booster circuit (simple, no peaking); and FIG. 6c shows a comparison of the current in (i) the simple case, (ii) the sweeping out only and (iii) when both boosting and sweeping out are used. DESCRIPTION The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer