RF switch and attenuator core — 5 Ohm series resistance at 100 MHz
The MPP4205-206/TR is a single PIN diode in a 0402 (1005 Metric) surface-mount package, designed for RF switching and attenuator applications up through low-GHz bands. Its 5 Ohm series resistance at 10 mA forward current and 100 MHz sets the insertion loss floor — in a typical SPDT switch the diode contributes roughly 0.2 dB loss per series element at that bias.
0.15 pF capacitance — isolation in the off state
Capacitance is 0.15 pF at 10 V reverse bias and 1 MHz. That ultra-low value keeps the diode from coupling the RF signal across the junction when reverse-biased, delivering isolation above 20 dB at 2 GHz in a shunt configuration. The 70 V peak reverse voltage rating gives headroom for high-power transmit paths without breakdown.
Temperature range and package — where it fits
The 0402 case keeps the parasitic inductance low — critical for maintaining the 5 Ohm series resistance spec up to several GHz without package resonance.