UM4300.

The UM4300 is a diode chip of extremely thick intrinsic region with a low thermal resistance construction.It is intended for use in linear attenuators operationg from HF to beyond 1GHz.

Features of the UM4300 are:(1)extremely low distortion performance;(2)useful frequency range extends below 500KHz;(3)power dissipation to 20W;(4)voltage ratings to 1000V.

The absolute maximum ratings of the  UM4300 can be summarized as:(1)A,25 pin temperature:20W.7.5/W;(2)B&E(axial leads),1/2 in.(12.7mm)total lead length to 25 contact:10W,15/W;(3)B&E(axial leads),free air:2.5W;(4)C(studded):25 stud temperature:20W,7.5/W;(5)D(insulated stud),25 stud temperature:15W,10/W;(6)all packages,1s pulse(single)at 25 ambient:500KW;(7)operating and storage temperature raneg:-65 to +175.

If you want to know more information such as the electrical characteristics about the UM4300, please download the datasheet in www.seekic.com or www.chinaicmart.com .