STMicroelectronics LET9180

Overview

LET9180 from STMicroelectronics is a 180 W, 32 V common-source n-channel enhancement-mode LDMOS RF power transistor for broadband industrial and commercial applications up to 2 GHz. It delivers 175–180 W output power with 18–20 dB gain and 60–69% drain efficiency at 860 MHz under 32 V supply, in push-pull configuration, targeting UHF broadcast amplifiers and wireless infrastructure final stages.

For engineers reviewing the LET9180 datasheet, LET9180 pinout, LET9180 application, or LET9180 equivalent, key selection criteria include its 80 V V(BR)DSS rating, 0.55 °C/W junction-to-case thermal resistance, BeO-free M246 package, and verified load mismatch tolerance up to 65:1 VSWR at full output - critical for ruggedized RF power amplifier design.

Technical Context

The LET9180 operates as a lateral double-diffused MOSFET in common-source configuration, optimized for wideband RF power amplification from DC to 2 GHz. Its static characteristics include VGS(th) of 2.0–5.0 V, RDS(ON) ≤ 1.2 Ω at VGS = 10 V, and gate input capacitance (CISS) of 70 pF at 32 V.

Dynamically, it sustains 180 W POUT at 860 MHz with 19 dB typical power gain and 65% typical drain efficiency under 32 V/500 mA quiescent bias. Thermal design is enabled by low RthJC (0.55 °C/W) and maximum junction temperature of 200 °C, supporting high-reliability continuous-wave operation.

Key Specifications

Pinout & Package

The LET9180 is housed in the M246 hermetically sealed, flanged, wide-body ceramic/metal package (22.86 mm × 29.08 mm × 5.59 mm), BeO-free, with integrated source tab for low-inductance grounding and thermal path optimization.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF power transistor applications.

Compared with PD57018-E and MRF101AN, the LET9180 offers broader bandwidth (DC–2 GHz), higher load mismatch resilience, and optimized thermal performance for UHF broadcast and industrial heating - making it uniquely suitable where frequency agility and ruggedness dominate over narrowband linearity or miniaturization.

Availability

LET9180 is available at Aetrix Electronics and suitable for UHF broadcast transmitters, wireless infrastructure base stations, industrial RF heating systems, and avionics communication amplifiers requiring stable component supply and long-term production continuity.

Supply support for LET9180 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing analog, MCU, power, and RF components for industrial, automotive, and consumer markets.

The LET9180 belongs to ST's LDMOS RF power transistor product line, engineered specifically for high-efficiency, high-reliability broadband amplification in commercial broadcast and industrial RF energy applications.

FAQ

What is the recommended gate bias voltage for LET9180 in Class AB operation?

The LET9180 specifies VGS(Q) = 2.0–5.0 V at ID = 100 mA and VDS = 28 V. For Class AB final-stage operation at 500 mA quiescent drain current, ST recommends a gate bias of +3.8 V ±0.2 V using a stabilized, low-noise voltage source with ≥100 nF local decoupling to suppress oscillation.

Can LET9180 operate safely at 36 V drain supply?

Yes - although rated for 32 V typical operation, the LET9180's 80 V V(BR)DSS rating and SOA curves in the datasheet confirm safe operation at 36 V with appropriate derating of output power and thermal management. At 36 V, POUT is limited to ≤160 W to maintain junction temperature below 200 °C under worst-case ambient conditions.

Is the M246 package RoHS-compliant and ECOPACK® certified?

Yes - the LET9180's M246 package meets RoHS Directive 2011/65/EU and is classified as ECOPACK®2, ST's highest environmental compliance grade. It contains no lead in solderable terminations, no halogenated flame retardants, and uses BeO-free ceramic substrate per ST's public ECOPACK® documentation.

Does LET9180 require external gate protection diodes?

No - the LET9180 integrates gate protection structures sufficient for standard RF PA handling and ESD events up to ±1 kV HBM. External gate Zener clamps are unnecessary unless operating in exceptionally high-RF-noise environments (e.g., near radar transmitters), where localized transient suppression may be added per ST AN4302 guidelines.