Microchip Technology UM7310SM

Overview

UM7310SM from Microsemi is a surface-mount PIN diode optimized for RF switching and linear attenuator applications up to 1 GHz. It features 1000 V reverse voltage rating, 0.7 pF maximum capacitance at 100 V/1 MHz, 3.0 Ω maximum series resistance at 100 mA/100 MHz, 150 kΩ minimum parallel resistance, and 4.0 μs minimum carrier lifetime - enabling low-distortion signal control in HF–UHF instrumentation and communications systems.

For engineers reviewing the UM7310SM datasheet, UM7310SM pinout, UM7310SM application, or UM7310SM equivalent, key selection criteria include its 1000 V blocking capability, ultra-low 0.7 pF capacitance, thermally matched SM package with end-cap thermal rating (15 W @ 25°C), and suitability for high-linearity RF attenuators requiring distortion < –60 dBc.

Technical Context

This PIN diode operates as a voltage-controlled RF resistor: forward bias reduces series resistance (down to ~3 Ω), while reverse bias yields high impedance (>150 kΩ) and minimal capacitance (0.7 pF). Its 250 μm intrinsic region width and 4.0 μs carrier lifetime ensure transit-time-limited operation below 5 MHz - critical for maintaining linearity in analog RF gain control.

The UM7310SM uses a non-cavity, isolated stud-compatible surface-mount package (Style 'SM') with end-cap thermal termination. Thermal impedance is 18 °C/W under specified mounting conditions, supporting stable 15 W DC power dissipation at 25°C end-cap temperature - distinct from stud- or lead-mounted variants like UM7310C or UM7310D.

Key Specifications

Pinout & Package

UM7310SM uses Microsemi Style 'SM' surface-mount package: isolated, non-cavity, end-cap thermal termination. Dimensions match A-size footprint per datasheet Page 5. Two-terminal device with anode and cathode leads aligned for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PIN diode switching and attenuation applications.

Compared with UM7310SM, UMX7310SM delivers identical RF and thermal behavior with lead-free terminations, while UM7306SM trades 40% lower voltage rating for cost efficiency in medium-power applications - neither is pin-compatible with legacy through-hole UM7310C/D variants.

Availability

UM7310SM is available at Aetrix Electronics and suitable for HF transmitter attenuators, UHF radar switches, automated test equipment signal routing, and EMI immunity calibrators requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for UM7310SM 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 RF, analog, and radiation-hardened components for defense, aerospace, and industrial markets.

The UM7300 series was designed specifically for high-linearity, high-voltage RF switching and programmable attenuation in HF–UHF systems - emphasizing low distortion, thermal stability, and surface-mount manufacturability.

FAQ

What is the maximum RF frequency range supported by the UM7310SM?

The UM7310SM is characterized for operation from HF (300 kHz) up to 1 GHz, with verified linearity and low distortion performance across this band. Its 0.7 pF capacitance and 4.0 μs carrier lifetime ensure usable RF resistance control and minimal IMD generation below 5 MHz transit-time limit - making UM7310SM appropriate for broadband attenuators and switches in HF–UHF systems.

Does the UM7310SM require external heat sinking in standard PCB layouts?

UM7310SM does not require external heat sinks when operated within its 15 W power dissipation limit at 25°C end-cap temperature, provided the PCB uses ≥1 oz copper with ≥1 cm² thermal pad connected to the cathode end-cap. Its 18 °C/W thermal impedance assumes direct copper pour contact - adding a small heatsink further extends safe operating area for pulsed RF loads.

Is the UM7310SM pin-compatible with other UM7300 series packages like UM7310C or UM7310D?

No, UM7310SM is not pin-compatible with UM7310C (stud-mount) or UM7310D (isolated stud-mount). The UM7310SM uses a two-terminal surface-mount footprint (Style 'SM', A-size), while UM7310C/D use threaded metal packages with different mechanical interfaces and thermal paths. Board redesign is required when substituting UM7310SM for through-hole UM7310C/D variants.

What is the typical forward voltage drop of the UM7310SM at 100 mA DC bias?

Per the UM4300/UM7300 family's typical VF vs. IF curve on Page 2, the UM7310SM exhibits approximately 0.95 V forward voltage drop at 100 mA DC bias and 25°C. This value remains stable across temperature due to thermally matched construction, supporting accurate bias current control in precision attenuator circuits using the UM7310SM.

Can the UM7310SM be used in avalanche mode for transient protection?

No, the UM7310SM is not rated or characterized for avalanche operation. It is designed strictly as a linear RF switch/attenuator diode with 1000 V reverse breakdown specification under DC or RF peak conditions - not repetitive avalanche energy handling. For transient suppression, dedicated TVS diodes such as Microchip's MMBZ52xx series should be used instead of UM7310SM.