This part is a kind of semiconductor called 4739AP.

Function of this product has 1N4739A.

Manufacturers : ETC

Image and pinout :

Some of the text within the PDF file :

FORMOSA MS 1N4728A~1N4761A Zener diode Features 1. High reliability 2. Very sharp reverse characteristic 3. Low reverse current level 4. VZ-tolerance± 5% Applications Voltage stabilization Absolute Maximum Ratings Tj=25? Parameter Power dissipation Z-current Junction temperature Storage temperature range Test Conditions Tamb= 50? Type Symbol PV IZ Tj Tstg Value 1 PV/VZ 200 -65~+175 Unit W mA ? ? Maximum Thermal Resistance Tj=25? Parameter Junction ambient Test Conditions I=9.5mm(3/8”) TL=constant Symbol RthJA Value 100 Unit K/W Electrical Characteristics Tj=25? Parameter Forward voltage Test Conditions IF=200mA Type Symbol Min Typ Max Unit VF 1.2 V FORMOSA MS 1 FORMOSA MS 1N4728A~1N4761A Type 1N4728A 1N4729A 1N4730A 1N4731A 1N4732A 1N4733A 1N4734A 1N4735A 1 [ ... ]

4739AP PDF Datasheet Download