Photonic digital-to-analog converters (DACs) can achieve bandwidths far beyond those of electronic DACs. The PONyDAC project is investigating a novel photonic DAC, the PONyDAC (Precise Optical Sinc-shaped Nyquist Pulse Synthesizer DAC), which combines precise Nyquist pulse synthesis with a time-interleaved DAC concept. The concept is compatible with integration into silicon photonics technology and enables bandwidths well above those of electronic DACs, as well as above the bandwidth of the Mach-Zehnder modulators used. Based on the results of the first phase of the PONyDAC project, the second phase of PONyDAC will a) develop and characterize a monolithic-integrated area-efficient PONyDAC chip in an advanced, photonic silicon germanium BiCMOS technology. The single-chip PONyDAC shall operate more than 100 GHz sampling rate and achieve an optical bandwidth of more than 100 GHz. Furthermore, b) a new method for electronic-photonic arbitrary signal generation (sampling-points-to-analog conversion (SPAC)) shall be investigated and validated by measurements. Finally, c) the potential of extremely broadband thin-film lithium niobate modulators in lithium niobate-on-insulator (LNOI) technology for PONyDAC and SPAC will be explored. LNOI modulators can be integrated in silicon photonics technology and exhibit much larger bandwidth than conventional silicon modulators. They have the potential to enable single-chip photonic DACs with several 100 GHz of contiguous bandwidth without frequency interleaving in a silicon photonics technology.