# TVS diode identification

I'm trying to ID diodes on a board - the markings on the diodes are "BK 9EJ3D". I understand this is a TVS diode and it's being used to clamp RS485 differential pair to ground with a termination circuit into a MAX 485 driver (485 to ttl). They measure around 730 ohm in both directions when I use a multimeter. Signal is something similar to DMX.

Any help appreciated.

• How do you know it is a TVS? If you know its package and role, just find a suitable replacement from one of the big vendors. Oct 23, 2019 at 13:41

The component might be an SMF14A by Littelfuse, a unidirectional suppressor diode (i.e. a Zener designed for suppression purposes) with breakdown between 15.6 and 17.2 volts. Its marking code according to the datasheet is BK.