The BZX84C4V7 is a small signal diode manufactured by Diotec. It is a Zener diode used for voltage regulation and suppression of transients. It has a nominal breakdown voltage of 4.7V and a maximum power dissipation of 500mW. It has a wide range of operating temperatures from -55 to +150°C, and a low reverse leakage current of 0.1mA at 4.7V. The package of the part is a SOD-123.