UM4001SM

RF Diode Overview

The UM4001SM is a silicon PIN diode from the UM4000 series, manufactured by Microchip Technology. It features a hermetic MELF (SM) package with a standard Sn/Pb finish. The device has a reverse voltage rating of 100 V at 10 uA and a maximum power dissipation of 25 W at 25°C end cap temperature. Electrical characteristics include a typical series resistance of 0.5 Ω at 100 MHz, a capacitance of 3 pF at 100 V reverse bias, and a carrier lifetime greater than 5 µs.

RF Diode Feature Summary

• High charge storage and long carrier lifetime enable control of high RF levels with relatively low bias current.
• Peak RF voltages can be handled well in excess of applied reverse bias voltage.
• Non-cavity design with thermally matched configuration for reliable performance.
• Low capacitance and low conductance at zero bias voltage.

RF Diode Applications

• Low distortion switches and attenuators in HF through S band frequencies.
• High power UHF phase shifters and megawatt peak-power duplexers.
• Antenna selectors and couplers where inductance and capacitance elements are switched in filter or cavity networks.

RF Diode Procurement Notes

Verify RoHS compliance status before procurement, as the standard UM4000 series utilizes a Sn/Pb finish which is non-compliant. For lead-free requirements, confirm availability of the UMX prefix variant. Confirm that the SM package style matches the intended surface mount footprint and soldering profile specifications.

RF Diode Selection Notes

Select the UM4001SM when a 100 V reverse voltage rating is required within the UM4000 series. Consider the UM4900 series if higher power dissipation ratings are necessary due to its shorter thermal path. Ensure the application operates within the specified frequency range of HF through S band for optimal switch and attenuator performance.

RF Diode Part Context

The UM4001SM belongs to the UM4000/UM4900 family of high power PIN diodes characterized by thick I-regions and long carrier lifetimes. While electrically equivalent to the UM4900 series, the UM4000 series typically offers lower power ratings due to differences in the thermal path between the chip and the package.

RF Diode Replacement Considerations

For RoHS compliant replacements, use the UMX4001SM variant which maintains identical electrical specifications but features a matte tin finish instead of the standard Sn/Pb finish.