Microchip Technology UM7512DR

Overview

UM7512DR from Microsemi is a high-voltage, hermetically sealed power PIN diode designed for RF/microwave switching and attenuation in demanding medical (MRI/CAT scan) and military systems. It features 1200 V reverse voltage rating, ≤0.5 µA reverse leakage at rated voltage, 1.0 Ω typical series resistance at 100 MHz/50 mA, and metallurgically bonded fused-in-glass construction for thermal reliability.

For engineers reviewing the UM7512DR datasheet, UM7512DR pinout, UM7512DR application, or UM7512DR equivalent, key selection criteria include reverse voltage margin, low distortion at 100 MHz, thermal resistance under stud-mount conditions, and MIL-STD-750 HTRB screening compliance at 150 °C.

Technical Context

The UM7512DR operates as a current-controlled RF switch/attenuator using a thick, precisely controlled 100 µm I-region to sustain high reverse bias while maintaining carrier lifetime of 2.5–3.5 µs. Its fused-in-glass hermetic package enables stable operation from –65 °C to +175 °C with no voids or particulates.

Thermal management relies on stud-mounting: at 25 °C stud temperature, it delivers 10 W continuous dissipation (θ_A = 15 °C/W), and supports 35 kW single-pulse peak power. Reverse bias harmonic distortion is ≥60 dBc at 0 dBm input, confirming low intermodulation in sensitive receiver front-ends.

Key Specifications

Pinout & Package

UM7512DR uses a hermetic, stud-mounted "DR" package with two terminals: anode and cathode. The metal stud serves as the cathode terminal and primary heat path; the top cap is the anode. Mounting requires torque-controlled compression against a heatsink.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage PIN diode applications.

Compared with UM7512D and UMX7512B, the UM7512DR uniquely combines hermetic reliability, 10 W stud-mounted dissipation, and MIL-STD-750 screening-making it the only choice for deployed military radar and clinical MRI systems requiring zero field-failure tolerance.

Availability

UM7512DR is available at Aetrix Electronics and suitable for MRI gradient amplifier switching, radar T/R module isolation, and military HF/VHF communications requiring stable component supply across extended temperature and high-reliability operational lifecycles.

Supply support for UM7512DR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog and RF components for aerospace, defense, and medical markets.

The UM7500 series was engineered specifically for high-power RF switching and attenuation in mission-critical systems where hermeticity, voltage margin, and thermal robustness are non-negotiable design requirements.

FAQ

What is the maximum continuous power dissipation for UM7512DR?

The UM7512DR supports 10 W continuous power dissipation when mounted to a heatsink at 25 °C stud temperature, with a thermal resistance of 15 °C/W. This rating assumes proper torque and thermal interface material per Microsemi's mechanical installation guidelines. Exceeding this limit risks parametric shift or catastrophic failure.

Does UM7512DR meet MIL-STD-750 reliability requirements?

Yes, UM7512DR is screened per MIL-STD-750 Method 1082 (High Temperature Reverse Bias) at 960 V (80% of 1200 V rating) and 150 °C for 1000 hours. This qualification confirms its suitability for defense-grade radar and avionics applications where long-term parameter stability under stress is mandatory.

What is the I-region width of UM7512DR and why does it matter?

The UM7512DR has a precisely controlled 100 µm I-region width. This dimension directly determines its 1200 V reverse breakdown voltage and influences carrier lifetime, series resistance, and RF impedance-making it critical for achieving the specified low distortion and high-isolation performance in RF switch designs.

Can UM7512DR be used in surface-mount designs?

No, UM7512DR uses a stud-mounted "DR" package intended for bolt-down thermal and electrical interface to a heatsink. Surface-mount variants (e.g., UM7512SM) exist in the same family but differ mechanically and thermally-UM7512DR must be installed using torque-controlled mounting hardware per datasheet mechanical drawings.

What is the typical forward voltage drop of UM7512DR at 50 mA?

The UM7512DR exhibits a typical forward voltage drop of 0.8–1.0 V at 50 mA DC bias. This low V_F reduces driver-stage power consumption and self-heating in high-duty-cycle RF switch applications, contributing to overall system efficiency and thermal management.