This paper presents a single-photon avalanche diode (SPAD) in 55 nm bipolar-CMOS-DMOS (BCD) technology. In order to realize a SPAD having sub-20 V breakdown voltage for mobile applications while preventing high tunneling noise, a high-voltage N-well available in BCD is utilized to implement the avalanche multiplication region. The resulting SPAD has a breakdown voltage of 18.4 V while achieving an excellent dark count rate of 4.4 cps/µm2 at the excess bias voltage of 7 V in spite of the advanced technology node. At the same time, the device achieves a high peak photon detection probability (PDP) of 70.1% at 450 nm thanks to the high and uniform E-field. Its PDP values at 850 and 940 nm, wavelengths of interest for 3D ranging applications reach 7.2 and 3.1%, respectively, with the use of deep N-well. The timing jitter of the SPAD, full width at half maximum (FWHM), is 91 ps at 850 nm. It is expected that the presented SPAD enables cost-effective time-of-flight and LiDAR sensors with the advanced standard technology for many mobile applications.