Microchip Technology UM7514SM

Overview

UM7514SM from Microsemi is a high-voltage, surface-mount power PIN diode designed for RF/microwave switching and attenuation in MRI, CAT scan, and military radar systems. It features 1400 V reverse voltage rating, ≤0.5 µA reverse leakage at rated voltage, 0.8–1.0 Ω series resistance at 100 MHz/50 mA, 2.5–3.5 µs carrier lifetime, and 100–150 kΩ parallel resistance at 100 V/100 MHz.

For engineers reviewing the UM7514SM datasheet, UM7514SM pinout, UM7514SM application, or UM7514SM equivalent, key selection criteria include reverse voltage margin for pulsed RF systems, low harmonic distortion (R2/R3 ≥80 dBc under forward bias), thermal stability up to +175 °C, and hermetic fused-in-glass construction for high-reliability medical and defense deployments.

Technical Context

The UM7514SM implements a fully passivated silicon PIN structure with precisely controlled 100 µm I-region width, enabling stable reverse characteristics and low leakage across temperature. Its metallurgically bonded, thermally matched construction ensures reliable power dissipation up to 7.5 W at 25 °C end-cap temperature.

Designed for RF switch/attenuator circuits, it delivers low-loss operation at 100 MHz (typical Rs = 0.9 Ω) and maintains harmonic distortion suppression of ≥80 dBc (R2a/a, R3a/a) under 30 W forward-biased RF conditions - critical for MRI gradient coil drivers and T/R module isolation.

Key Specifications

Pinout & Package

UM7514SM uses a hermetically sealed, fused-in-glass surface-mount package (Style "SM") with two terminals: anode and cathode. The package is RoHS-compliant and compatible with automated placement equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UMX7514B, UM7514SM offers identical electrical performance but lacks formal RoHS certification; versus QPD1005, UM7514SM enables compact SMT integration and lower thermal impedance, though with 100 V less voltage headroom.

Availability

UM7514SM is available at Aetrix Electronics and suitable for MRI gradient drivers, CAT scan RF attenuators, and military radar T/R modules requiring stable component supply, long-lifecycle assurance, and traceable sourcing for Class III medical and defense programs.

Supply support for UM7514SM 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 imaging and radar systems, emphasizing hermeticity, voltage robustness, and thermal resilience.

FAQ

What is the maximum reverse voltage rating for UM7514SM?

The UM7514SM has a specified reverse voltage rating of 1400 V at 0.5 µA leakage current. This rating is validated per MIL-STD-750 test methods and applies under steady-state DC or low-duty-cycle RF conditions. Operation above this voltage risks irreversible junction breakdown. Derating is recommended for pulsed RF applications with high dv/dt transients.

Does UM7514SM meet RoHS requirements?

UM7514SM is not RoHS-compliant in its standard configuration. Microsemi offers the functionally identical UMX7514B variant with lead-free terminations and full RoHS documentation. For medical or consumer deployments requiring RoHS certification, UMX7514B must be selected instead of UM7514SM.

What is the thermal resistance of UM7514SM?

UM7514SM has a thermal resistance of 20 °C/W from end-cap to ambient (measured with 25 °C end-cap temperature). This value assumes proper PCB copper pour and solder joint integrity. At 7.5 W dissipation, the end-cap temperature rise is 150 °C above ambient - consistent with its +175 °C max operating limit.

Can UM7514SM be used in automatic SMT assembly lines?

Yes, UM7514SM is explicitly designed for compatibility with automated insertion equipment. Its Style "SM" footprint, defined on Microsemi Page 8, supports standard pick-and-place nozzles and reflow profiles. The fused-in-glass body resists mechanical stress during handling, and the terminals accept standard SnPb or lead-free solder pastes.

How does UM7514SM achieve low harmonic distortion?

UM7514SM achieves ≥80 dBc forward-bias harmonic distortion (R2a/a, R3a/a) at 100 MHz/30 W via precise 100 µm I-region width control and high carrier lifetime (2.5–3.5 µs), which minimize nonlinear charge modulation. Its fully passivated chip surface also suppresses surface-state-induced intermodulation in high-dynamic-range MRI and radar waveforms.