UM7301B

RF Diode Overview

The UM7301B is a switching and attenuator PIN diode from the UM7300 series, manufactured by Microsemi (now part of Microchip Technology). It features an extremely thick intrinsic region with low thermal resistance, designed for very low distortion linear attenuators and specialized RF functions. The device operates effectively from HF to beyond 1 GHz, with transit time frequencies below 5 MHz ensuring low distortion. Key electrical characteristics include a maximum reverse current of 10 uA at rated voltage, a maximum series resistance of 3.0 Ohms at 100 mA forward current and 100 MHz, and a maximum capacitance of 0.7 pF at 100 V reverse bias and 1 MHz. The minimum carrier lifetime is 4.0 us, and the I-region width is at least 250 um.

RF Diode Feature Summary

• Extremely low distortion performance suitable for precision applications
• Low capacitance design enabling operation at high frequencies
• Thermally matched construction for stable performance
• Capable of holding off high RF voltage levels at low DC reverse bias

RF Diode Applications

• RF Switching
• Linear RF Attenuators
• Specialized RF functions requiring low distortion

RF Diode Procurement Notes

Verify the specific package style required, as the UM7300 series offers multiple mechanical configurations including stud and surface mount options. Confirm RoHS compliance requirements; standard versions may differ from UMX7300 variants. Ensure the selected part matches the thermal management needs of the application, considering the specified power dissipation ratings relative to the mounting condition.

RF Diode Selection Notes

Select the UM7301B when low capacitance and low distortion are critical for frequencies extending beyond 1 GHz. Compare against the UM4300 series if higher power handling capability is prioritized over lower capacitance. Evaluate the required package style (e.g., SM, C, D) based on available board space and thermal dissipation constraints. Verify that the 100V reverse voltage rating meets the peak RF voltage requirements of the circuit.

RF Diode Part Context

The UM7301B belongs to the UM7300 series of PIN diodes, which are characterized by a large cross-sectional chip area and thick intrinsic region. This series is distinct from the UM4300 series primarily by offering lower capacitance, making it preferable for high-frequency applications where signal integrity and minimal distortion are paramount. Both series share similar construction principles aimed at enhancing thermal performance and linearity.

RF Diode Replacement Considerations

For RoHS compliant alternatives, specify the UMX7301 variant. Direct functional replacements within the same family include other UM7300 series parts with different voltage ratings (e.g., UM7302, UM7306) if the operating voltage allows.