UM4001B

RF Diode Overview

The UM4001B is a high-power silicon PIN diode from the UM4000 series, designed for HF through S-band applications. It features a hermetic glass axial package (Style A) with a Sn/Pb standard finish. The device provides a reverse voltage rating of 100 V at 10 uA leakage current and supports up to 25 W power dissipation at a 25°C pin temperature. Key electrical parameters include a typical series resistance of 0.5 Ω at 100 mA/100 MHz, a capacitance of 3 pF at 100 V/1 MHz, and a carrier lifetime exceeding 5 µs. These characteristics enable control of high RF levels with low bias currents.

RF Diode Feature Summary

• Long carrier lifetime and thick I-regions facilitate high RF level control with relatively low bias current.
• Capable of handling peak RF voltages significantly in excess of the applied reverse bias voltage.
• Non-cavity design ensures compatibility with automatic insertion equipment.

RF Diode Applications

• Low distortion switches
• Attenuators
• High power UHF phase shifters
• Megawatt peak-power duplexers
• Antenna selectors and couplers

RF Diode Procurement Notes

Verify RoHS compliance requirements before ordering, as the standard UM4001B utilizes a Sn/Pb finish. For lead-free specifications, select the UMX prefix variant (e.g., UMX4001B), which features a matte tin finish. Confirm that the specific manufacturing lot meets the required environmental directives for your deployment region.

RF Diode Selection Notes

Select the UM4001B when operating within HF to S-band frequencies requiring robust thermal performance in an axial package. Ensure the application demands a 100 V reverse voltage rating and benefits from the long carrier lifetime for efficient switching. Verify that the 25 W power dissipation limit aligns with the system's thermal management capabilities.

RF Diode Part Context

The UM4001B belongs to the UM4000 series of high-power PIN diodes manufactured by Microsemi (now Microchip Technology). This series is electrically equivalent to the UM4900 series but utilizes a different package style with a longer thermal path, resulting in lower power ratings compared to the stud-mounted UM4900 variants.

RF Diode Replacement Considerations

The UM4901 is the electrically equivalent counterpart in the UM4900 series, offering higher power dissipation due to its stud package design. Direct substitution requires verifying mechanical fitment differences between the axial UM4001B and the stud-style UM4901.

RF Diode FAQ

What is the maximum peak RF voltage the UM4001B can handle?

The UM4001B can handle peak RF voltages well in excess of its applied reverse bias voltage.

How does the UM4001B differ from the UM4901?

While electrically equivalent, the UM4001B uses an axial glass package with a longer thermal path, whereas the UM4901 uses a stud package with a shorter thermal path, allowing for higher power dissipation.

Is the UM4001B available in a RoHS-compliant version?

Yes, the RoHS-compliant version is available with the UMX prefix (UMX4001B) and features a matte tin finish instead of the standard Sn/Pb finish.