STMicroelectronics LET9060STR

Overview

LET9060STR from STMicroelectronics is a common-source N-channel enhancement-mode lateral MOSFET designed for RF power amplification up to 1 GHz. It delivers 60 W output power with 17.2 dB gain at 960 MHz under 28 V supply and 300 mA quiescent drain current, featuring 1.0 °C/W junction-to-case thermal resistance and PowerSO-10RF straight-lead package for high-reliability SMD assembly in base station transmitters.

For engineers reviewing the LET9060STR datasheet, LET9060STR pinout, LET9060STR application, or LET9060STR equivalent, key selection criteria include its 80 V drain-source breakdown voltage, 60%–70% drain efficiency at 960 MHz, 77 pF input capacitance, load mismatch tolerance up to 20:1 VSWR, and JEDEC-approved PowerSO-10RF mechanical compatibility.

Technical Context

The LET9060STR operates in common-source configuration with fixed 28 V drain bias and 300 mA IDQ, optimized for broadband linear amplification in the 800–1000 MHz band. Its LDMOS architecture provides stable gain flatness and low intermodulation distortion across varying load impedances.

Thermal performance is enabled by direct die attachment to the exposed copper slug in the PowerSO-10RF package, supporting continuous 95 W power dissipation at TC = 70 °C. The device's 1.2 pF reverse transfer capacitance (CRSS) and 39 pF output capacitance (COSS) support wideband matching network design.

Key Specifications

Pinout & Package

LET9060STR uses the PowerSO-10RF straight-lead plastic package: 10-terminal SMD outline with exposed copper thermal pad, JEDEC-compliant footprint, and gull-wing–compatible lead geometry optimized for RF grounding and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF6VP2600HR5 and PD85008, LET9060STR uniquely balances 60 W output, SMD manufacturability, and 1.0 °C/W thermal resistance in a JEDEC-standard footprint-making it optimal for mid-power macrocell and ruggedized mobile infrastructure where reliability and assembly yield are critical.

Availability

LET9060STR is available at Aetrix Electronics and suitable for macrocell base station transmitters, public safety radio amplifiers, ISM band industrial heaters, and avionics communication test equipment requiring stable component supply across extended product lifecycles.

Supply support for LET9060STR 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, Switzerland, designing and manufacturing analog, MEMS, power, and microcontroller products for industrial, automotive, and communications markets.

LET9060STR belongs to ST's LdmoST plastic family of RF power transistors, engineered specifically for high-efficiency, high-linearity, and thermally robust amplification in commercial and industrial wireless infrastructure.

FAQ

What is the recommended gate bias network for LET9060STR in Class AB operation?

A stable Class AB bias requires a dual-resistor divider from +28 V to ground, feeding through a 100 Ω gate-stopper resistor into the gate terminal. A 100 nF RF bypass capacitor must shunt the gate bias node to the source plane. Gate voltage must be set between 2.0 V and 5.0 V (typical VGS(Q) = 3.5 V) to achieve 300 mA IDQ at VDS = 28 V, verified with DC source measurement before RF drive application.

Can LET9060STR operate safely at 32 V drain supply?

No. Although V(BR)DSS is rated at 80 V, the device is characterized and qualified only at 28 V per datasheet conditions. Operating above 28 V violates ST's specified test conditions and voids reliability guarantees. Exceeding 28 V increases risk of thermal runaway due to positive temperature coefficient of transconductance and may cause premature failure even below absolute maximum ratings.

Is the PowerSO-10RF straight-lead package compatible with standard reflow profiles?

Yes. PowerSO-10RF straight-lead meets JEDEC J-STD-020C MSL 3 requirements and is qualified for Pb-free reflow with peak temperatures up to 260 °C. Recommended profile includes ramp rate ≤3 °C/s, soak at 150–200 °C for 60–120 s, and time above liquidus (217 °C) of 60–90 s. Thermal pad must be fully soldered using ≥75% coverage and stencil-applied solder paste.

Does LET9060STR require external ESD protection on the gate pin?

No. LET9060STR integrates on-die gate protection diodes rated to HBM Class 2 (2 kV) and MM Class M3 per Table 6. External TVS devices are unnecessary for standard handling and PCB-level ESD events. However, gate traces must remain short (<5 mm) and avoid routing near noisy digital signals to prevent coupling-induced gate oxide stress during operation.