Visible light communication system-on-a-chip

Abstract

This disclosure relates to visible light communication (VLC) system-on-a-chip (SoC) systems/methods and VLC system-in-a-package (SiP) systems/methods. A VLC SoC system may include an integrated circuit comprising a VLC encoder and an LED driver fabricated on a first portion of a silicon substrate and an LED fabricated in a compound semiconductor selectively grown on a second portion of the silicon substrate. A VLC SiP system may include an integrated circuit comprising a VLC encoder and an LED driver fabricated on a silicon substrate and an LED fabricated in a compound semiconductor. The integrated circuit and the LED may be packaged in a SiP module. Interconnects may be formed between the integrated circuit and the LED.

What is claimed is: 
     
         1 . A method of making a visible light communication (VLC) system-on-a-chip (SoC) system, comprising:
 fabricating an integrated circuit comprising a VLC encoder and an LED driver on a first portion of a silicon substrate;   selectively growing a compound semiconductor on a second portion of the silicon substrate; and   fabricating an LED in the compound semiconductor selectively grown on the second portion of the silicon substrate;   wherein the LED is configured as a VLC transmitter, the VLC encoder is configured to encode a VLC signal, and the LED driver is configured to drive the LED to emit visible light in accordance with the VLC signal.   
     
     
         2 . The method of  claim 1 , wherein the step of selectively growing the compound semiconductor on the second portion of the silicon substrate comprises:
 using a photo mask on the silicon substrate to define an opening;   depositing seeds into the opening; and   selectively growing the compound semiconductor in the opening.   
     
     
         3 . The method of  claim 1 , further comprising:
 growing a buffer layer between the compound semiconductor and the second portion of the silicon substrate.   
     
     
         4 . The method of  claim 1 , wherein the VLC encoder comprises a Manchester encoder. 
     
     
         5 . The method of  claim 1 , wherein the integrated circuit further comprises a serializer for serializing the VLC signal. 
     
     
         6 . The method of  claim 1 , the integrated circuit further comprises a pre-equalizer using an overshoot/undershoot circuit configured to accelerate charging and discharging of the LED. 
     
     
         7 . The method of  claim 1 , further comprising:
 fabricating a photodetector in the compound semiconductor selectively grown on the second portion of the silicon substrate, or fabricating the photodetector in the same silicon substrate;   wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to decode the VLC signal received by the photodetector.   
     
     
         8 . The method of  claim 7 , wherein the integrated circuit further comprises an active feedback based ambient light cancellation circuit comprising a low pass filter, an error amplifier, and an NMOSFET. 
     
     
         9 . The method of  claim 7 , further comprising:
 integrating a micro-lens on top of the photodetector.   
     
     
         10 . The method of  claim 1 , further comprising:
 fabricating a photodetector on the first portion of a silicon substrate;   integrating a micro-lens on top of the photodetector;   wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to decode the VLC signal received by the photodetector.   
     
     
         11 . A visible light communication (VLC) system-on-a-chip (SoC) system, comprising:
 an integrated circuit comprising a VLC encoder and an LED driver fabricated on a first portion of a silicon substrate; and   an LED fabricated in a compound semiconductor selectively grown on a second portion of the silicon substrate;   wherein the LED is configured as a VLC transmitter, the VLC encoder is configured to encode a VLC signal, and the LED driver is configured to drive the LED to emit visible light in accordance with the VLC signal.   
     
     
         12 . The system of  claim 11 , wherein the system is a single chip integrated circuit. 
     
     
         13 . The system of  claim 11 , further comprising a buffer layer between the compound semiconductor and the second portion of the silicon substrate. 
     
     
         14 . The system of  claim 11 , wherein the VLC encoder comprises a Manchester encoder. 
     
     
         15 . The system of  claim 11 , wherein the integrated circuit further comprises a serializer for serializing the VLC signal. 
     
     
         16 . The system of  claim 11 , wherein the integrated circuit further comprises pre-equalizer using an overshoot/undershoot circuit configured to accelerate charging and discharging of the LED. 
     
     
         17 . The system of  claim 11 , further comprising:
 a photodetector fabricated in the compound semiconductor selectively grown on the second portion of the silicon substrate;   wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to process the VLC signal received by the photodetector.   
     
     
         18 . The system of  claim 17 , wherein the integrated circuit further comprises an active feedback based ambient light cancellation circuit comprising a low pass filter, an error amplifier, and an NMOSFET. 
     
     
         19 . The system of  claim 17 , further comprising:
 a micro-lens integrated on top of the photodetector.   
     
     
         20 . The system of  claim 11 , further comprising:
 a photodetector fabricated on the first portion of the silicon substrate; and   a micro-lens integrated on top of the photodetector;   wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to decode the VLC signal received by the photodetector.   
     
     
         21 . A method of making a visible light communication (VLC) System-in-Package (SiP) system, comprising:
 fabricating an integrated circuit comprising a VLC encoder and an LED driver on a silicon substrate;   fabricating an LED in a compound semiconductor;   packaging the integrated circuit and the LED in a SiP module;   forming interconnects between the integrated circuit and the LED;   wherein the LED is configured as a VLC transmitter, the VLC encoder is configured to encode a VLC signal, and the LED driver is configured to drive the LED to emit visible light in accordance with the VLC signal.   
     
     
         22 . The method of  claim 21 , further comprising packaging the integrated circuit and the LED in a SiP module using a flip-chip method. 
     
     
         23 . The method of  claim 21 , wherein the interconnects comprise through-silicon vias and an interposer layer. 
     
     
         24 . The method of  claim 21 , wherein the VLC encoder comprises a Manchester encoder. 
     
     
         25 . The method of  claim 21 , wherein the integrated circuit comprises a serializer for serializing the VLC signal. 
     
     
         26 . The method of  claim 21 , wherein the integrated circuit further comprises a pre-equalizer using an overshoot/undershoot circuit configured to accelerate charging and discharging of the LED. 
     
     
         27 . The method of  claim 21 , further comprising:
 fabricating a photodetector in the compound semiconductor, wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to decode the VLC signal received by the photodetector.   
     
     
         28 . The method of  claim 27 , wherein the integrated circuit further comprises an active feedback based ambient light cancellation circuit comprising a low pass filter, an error amplifier, and an NMOSFET. 
     
     
         29 . The method of  claim 27 , further comprising:
 integrating a micro-lens on top of the photodetector.   
     
     
         30 . The method of  claim 21 , further comprising:
 fabricating a photodetector on the silicon substrate;   integrating a micro-lens on top of the photodetector;   wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to decode the VLC signal received by the photodetector.   
     
     
         31 . A visible light communication (VLC) System-in-Package (SiP) system, comprising:
 an integrated circuit comprising a VLC encoder and an LED driver fabricated on a silicon substrate;   an LED fabricated in a compound semiconductor; and   interconnects formed between the integrated circuit and the LED;   wherein the integrated circuit and the LED are packaged in a SiP module;   wherein the LED is configured as a VLC transmitter, the VLC encoder is configured to encode a VLC signal, and the LED driver is configured to drive the LED to emit visible light in accordance with the VLC signal.   
     
     
         32 . The system of  claim 31 , wherein the SiP module is packaged using a flip-chip method. 
     
     
         33 . The system of  claim 31 , wherein the interconnects comprise through-silicon vias and an interposer layer. 
     
     
         34 . The system of  claim 31 , wherein the VLC encoder comprises a Manchester encoder. 
     
     
         35 . The system of  claim 31 , wherein the integrated circuit comprises a serializer for serializing the VLC signal. 
     
     
         36 . The system of  claim 31 , wherein the integrated circuit further comprises a pre-equalizer using an overshoot/undershoot circuit configured to accelerate charging and discharging of the LED. 
     
     
         37 . The system of  claim 31 , further comprising:
 a photodetector fabricated in the compound semiconductor, wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to process the VLC signal received by the photodetector.   
     
     
         38 . The system of  claim 37 , wherein the integrated circuit further comprises an active feedback based ambient light cancellation circuit comprising a low pass filter, an error amplifier, and an NMOSFET. 
     
     
         39 . The system of  claim 37 , further comprising:
 a micro-lens integrated on top of the photodetector.   
     
     
         40 . The system of  claim 31 , further comprising:
 a photodetector fabricated on the silicon substrate;   a micro-lens integrated on top of the photodetector;   wherein the photodetector is configured as a VLC receiver to receive the VLC signal, and the integrated circuit is configured to decode the VLC signal received by the photodetector.