RF switch and attenuator workhorse in a common-cathode pair
The NXP BAP64-05W,115 is a silicon PIN diode configured as a common-cathode pair in a single SC-70 (SOT-323) package. It is specified for RF switching, attenuator, and limiter circuits from HF through low-GHz bands, where its 0.35 pF capacitance at 20 V and 1.35 Ω series resistance at 100 mA define the off-state isolation and on-state insertion loss, respectively.
Parametric anchor — capacitance and resistance at the bias point
The off-state capacitance is 0.35 pF measured at 20 V reverse bias and 1 MHz. That figure sets the isolation floor in a shunt-switch or series-shunt topology: at 1 GHz, 0.35 pF yields roughly 25 dB isolation per diode in a 50 Ω system, enough for most T/R-switch and antenna-diversity applications. Forward resistance drops to 1.35 Ω at 100 mA forward current, measured at 100 MHz. At that bias the diode is fully forward-biased and the insertion loss through a series-connected pair is under 0.3 dB in a 50 Ω path. Maximum continuous forward current is 100 mA, and total power dissipation is limited to 240 mW. The SC-70 package has a modest thermal footprint — derate the forward current if the ambient exceeds 85°C or if both diodes are biased simultaneously.
Package and mounting — SC-70 (SOT-323) footprint
The supplier device package is SC-70.