Small-signal dual diode for RF and protection
The STMicroelectronics STDD15-05WFILM is a standard dual common-cathode diode pair in a tiny SC-70 / SOT-323 package. It handles a peak reverse voltage of 15V and a maximum forward current of 10 mA, with a series resistance of 15Ω at 5 mA / 100 MHz and a low capacitance of 1 pF at 0V / 1 MHz. This combination makes it suited for RF signal steering, clamping, and ESD protection in compact, high-frequency circuits where capacitive loading must stay minimal.
STMicroelectronics lists the STDD15-05WFILM as obsolete.
What the key specs mean for your circuit
The 15V peak reverse voltage covers 5V and 3.3V signal rails with margin, but not 12V or 24V buses. The 10 mA current rating limits it to signal-level steering — not power rectification. The 15Ω series resistance at 100 MHz and 1 pF capacitance are the specs that matter for RF paths: low enough to pass a 2.4 GHz signal without excessive attenuation or loading. The common-cathode configuration lets you use it as a single-pole double-throw switch or a dual-series clamp with one shared cathode connection.