## 6 Conclusions  
The Buck DC/DC converter is a good approach for the last step of the power supply chain as a VLC driver. Some authors have proposed multi-phase solutions with high-order filters to achieve both high bandwidth and high efficiency. This is the context in which the technique of splitting the power between two DC/DC converters is proposed to further improve both the resolution of output voltage tracking and the efficiency of the VLC driver. To that end, one converter is in charge of communication tasks and the other handles lighting tasks. However, the real implementation of this solution introduces hardware complexity due to isolated issues either in previous steps of the power supply chain or in the VLC driver itself.  
This work introduces a proposed version of the TIBuck DC/DC converters, both to outperform solutions based on Buck DC/DC converters and to simplify the hardware complexity of previous solutions that use the split power technique. By naturally splitting power and with the help of the auxiliary Buck DC/DC converter, high efficiency, high resolution in output voltage tracking, and great communication capabilities are achieved as a VLC driver. All improvements are based on a deep analysis of the proposed TIBuck DC/DC converter as a VLC driver in terms of interaction with the proposed Buck DC/DC  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Ref.** & **Topology** & **Input Voltage Sources** & **Modulation Scheme** & **P\({}_{\text{O}}\) (W)** & **i\({}_{\text{max}}\)/2I\({}_{\text{o}}\)** & **f\({}_{\text{S}}\) (MHz)** & **n(C)** & **Distance (cm)** & **Bin Rate (Mbps)** & **EVM\({}_{\text{rms}}\)** \\ \hline
[21] & Two phase Buck DC/DC converter with high-order filter & 1 & 16-QAM & 10 & 0.9 & 4.5 & 87.5 & 100 & 0.5 & - \\ \hline
[22] & Two phase Buck DC/DC converter with high-order filter + synchronous Buck DC/DC converter & 2 1\({}^{\text{st}}\) & OFDM & 10 & 0.8 & 10\({}^{\text{st}}\) & 93.6 & 20 & 7.5 & 15 \\ \hline
[27] & By-Back DC/DC converter + Class B power amplifier & 1 & OFDM & 20 & 0.42 & 0.1 & 94 & 50 & 6 & 5 \\ \hline This work & Proposed TIBuck DC/DC converter & 1 & 64-QAM & 7 & 1 & 10\({}^{\text{st}}\) & 94 & 40 & 1.5 & 12 \\ \hline \hline \end{tabular}  
\({}^{\text{st}}\) One of them isolated. \({}^{\text{st}}\) This is the switching frequency of the DC/DC converter in charge of reproducing the communication signal. \({}^{\text{st}}\) This is the switching frequency of the DC/DC in charge of both biasing and supplying the class B power amplifier.  
\end{table}
Table 3: Comparison between power-efficient VLC drivers based on conventional PWM DC/DC converters.  
converter, evaluation of switching harmonic components, filtering effort, the temperature dependency of the resolution and the nature of the power flow.  
Finally, in other to prove the concept, a 7 W output power experimental prototype was built with 94% efficiency, reproducing a 64-QAM digital modulation scheme and achieving a bit rate of 1.5 Mbps, with an error in communication of 12%.  
[PERSON] and [PERSON] conceived and performed the experiments. [PERSON] and [PERSON] developed the adaptation of solutions to VLC and the design procedure. [PERSON] and [PERSON] analysed the data and wrote the paper. [PERSON], [PERSON] and [PERSON] contributed to the definition, the design, and the evaluation of the experiments and the revision of the paper. All authors have read and agreed to the published version of the manuscript.  
This work was funded by the Spanish Government under Project MCIU-22-PID2021-12770/OB-C21.  
Not applicable.  
Data Availability Statement: Data are contained within the article.