500 mOhm at 100 MHz — the RF switch spec that matters
The BA891,115 is an NXP standard PIN diode in a SOD-523 package, designed for RF switching and attenuator circuits where low series resistance at high frequency is the deciding parameter. Its 500 mOhm resistance at 10 mA forward current and 100 MHz keeps insertion loss low in the signal path, while the 0.9 pF capacitance at 3 V reverse bias maintains isolation at UHF frequencies. The 35 V peak reverse voltage gives headroom for DC bias networks in 50-Ohm systems.
Military-temperature junction rating — not just a number
The 715 mW power dissipation in the tiny SOD-523 package means the board layout must provide adequate copper area under the cathode pad to keep the junction below 150°C at the maximum forward current of 100 mA.