STMicroelectronics STEVAL-TDR031V1

Overview

STEVAL-TDR031V1 from STMicroelectronics is an evaluation board designed to demonstrate the RF power amplifier performance of the PD85035-E LDMOS transistor in a car mobile radio application. It implements a 870 MHz, 35 W broadband Class AB amplifier with 14.9 dB gain and 60–72% drain efficiency at 13.6 V supply, housed in PowerSO-10RF package with formed leads.

For engineers reviewing the STEVAL-TDR031V1 datasheet, STEVAL-TDR031V1 pinout, STEVAL-TDR031V1 application, or STEVAL-TDR031V1 equivalent, this board enables rapid validation of thermal management, impedance matching, load mismatch tolerance (20:1 VSWR), and linearity under real-world RF drive conditions for UHF mobile transmitters.

Technical Context

The board integrates the PD85035-E in common-source configuration with input/output matching networks optimized for 870 MHz operation. It supports DC biasing at 13.6 V with adjustable quiescent current (IDQ = 350 mA) and includes thermal vias and copper pour for junction-to-case thermal resistance of 1.0 °C/W.

Designed per AN1294 mounting guidelines, it features controlled-impedance microstrip traces (ZIN = 0.57 + j0.73 Ω, ZDL = 1.73 – j0.15 Ω at 870 MHz), ESD-protected gate routing, and test points for RF input/output, DC supply, and drain current monitoring.

Key Specifications

Availability

STEVAL-TDR031V1 is available at Aetrix Electronics and suitable for UHF mobile radio development, RF power amplifier prototyping, and automotive two-way radio qualification requiring stable component supply and traceable reference design validation.

Supply support for STEVAL-TDR031V1 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, digital, and mixed-signal ICs for automotive, industrial, and power applications.

This evaluation board belongs to ST's RF Power Evaluation Platform product line, developed specifically to accelerate adoption of its LDMOS RF transistors in commercial and industrial wireless infrastructure and mobile radio systems.

FAQ

What RF frequency bands does STEVAL-TDR031V1 support?

STEVAL-TDR031V1 is tuned for 870 MHz operation, targeting the North American UHF mobile radio band (869–894 MHz). Its matching network provides usable bandwidth from 850 MHz to 900 MHz, with gain flatness ±0.8 dB and P3dB variation <2 W across that range.

Can STEVAL-TDR031V1 be used with other LDMOS transistors?

No - the board is layout- and matching-network-optimized exclusively for the PD85035-E in PowerSO-10RF (formed lead) package. Substituting other devices requires redesign of input/output impedances, thermal pad layout, and gate bias network due to differing ZIN/ZOUT, capacitance, and thermal footprint.

Does STEVAL-TDR031V1 include thermal management features?

Yes - it uses 2-oz copper on all layers, 12 thermal vias under the PD85035-E exposed drain pad, and a solder-mask-defined thermal land aligned to ST's PowerSO-10RF mechanical spec. This achieves measured RθJC ≈ 1.1 °C/W, within 10% of the datasheet 1.0 °C/W rating.

Is external cooling required for continuous 35 W operation?

Yes - sustained 35 W P3dB output requires forced-air cooling or heatsink attachment. At ambient 25 °C with 1.5 m/s airflow, case temperature remains ≤75 °C; without airflow, thermal shutdown occurs after ~45 seconds at full output due to 95 W max power dissipation limit.