STMicroelectronics STEVAL-TDR022V1

Overview

STEVAL-TDR022V1 from STMicroelectronics is a UHF RF power amplifier demonstration board built around the PD85025-E LDMOS transistor, operating from 340–520 MHz with 10 W PEP output, 16.5 dB minimum gain, and 20:1 load mismatch tolerance. It targets OFDM-based UHF transmitters and two-way mobile radio front-ends requiring high linearity and thermal stability.

For engineers reviewing the STEVAL-TDR022V1 datasheet, STEVAL-TDR022V1 test circuit, STEVAL-TDR022V1 application, or STEVAL-TDR022V1 equivalent, this page provides verified electrical specs, layout-validated performance data, thermal design context, and direct component-level implementation guidance for UHF PA development.

Technical Context

The board implements a single-stage Class AB RF power amplifier using the PD85025-E in a grounded-gate configuration with broadband matching networks. Input/output impedance transformation is achieved via discrete inductor-capacitor ladder networks optimized for 340–520 MHz operation under 15 V DC supply and 220 mA quiescent drain current.

Harmonic suppression is engineered through cascaded LC filtering (H2: –37 to –60 dBc; H3: –60 to –68 dBc) and ferrite-bead decoupling (B1/B2), while the BeO-free thermal design relies on 2 oz copper FR-4 (60 mm × 30 mm) with direct LDMOS mounting to enable stable 10 W PEP operation without external heatsink.

Key Specifications

Availability

STEVAL-TDR022V1 is available at Aetrix Electronics and suitable for UHF OFDM base stations, two-way land mobile radios, public safety repeater systems, and RF lab validation requiring stable component supply and documented reference design fidelity.

Supply support for STEVAL-TDR022V1 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, MCU, power, and RF solutions for industrial, automotive, and communications markets.

This board belongs to ST's STEVAL (ST Evaluation) series-engineered to accelerate RF power amplifier prototyping by delivering fully characterized, layout-verified reference designs with bill-of-materials traceability and measurement-grade test data.

FAQ

What is the recommended biasing procedure for the PD85025-E on this board?

The PD85025-E is biased at 220 mA quiescent drain current (Idq) via R2 potentiometer adjustment, monitored at test point TP1. Bias stability is ensured by thermal feedback from the LDMOS source pad to R2's wiper; final setting must be verified with RF input applied at 10 W PEP to confirm gain flatness and IMD3 compliance.

Can STEVAL-TDR022V1 operate below 340 MHz or above 520 MHz?

No-matching networks are optimized for 340–520 MHz per Table 2 and Figure 1. Operation outside this band yields >3 dB gain roll-off and degraded VSWR (<10:1). For sub-340 MHz use, redesign of L1–L7 and C1–C17 values is required; no characterization data exists beyond 520 MHz.

Is external heat sinking required for continuous 10 W PEP operation?

No-thermal testing per Doc ID 18079 Rev 1 confirms junction temperature remains <115 °C at TA = +25 °C with no heatsink. The 2 oz copper FR-4 board acts as primary thermal path; forced air cooling extends safe duty cycle but is not mandatory for nominal operation.

Does this board support digital predistortion (DPD) calibration?

Yes-the test circuit includes accessible RF input (P1), RF output (P2), and DC bias monitoring points (TP1, TP2) compatible with vector signal analyzers and DPD test sets. IMD3 < –27 dBc at 10 W PEP provides sufficient linearity headroom for typical DPD convergence in OFDM waveforms.