STMicroelectronics PD55025STR-E

Overview

PD55025STR-E from STMicroelectronics is a N-channel enhancement-mode lateral MOSFET RF power transistor in PowerSO-10RF (straight lead) package, designed for common-source broadband amplification up to 1 GHz. It delivers 25 W output power at 500 MHz with 14.5 dB gain under 12.5 V supply and 200 mA quiescent drain current, featuring 1.2 °C/W junction-to-case thermal resistance and 40 V drain-source breakdown voltage - optimized for car mobile radio transmitters.

For engineers reviewing the PD55025STR-E datasheet, PD55025STR-E pinout, PD55025STR-E application, or PD55025STR-E equivalent, this device is selected for high-linearity, thermally stable RF power stages in commercial and industrial transceivers operating between 175–1000 MHz with 12–15.5 V supply rails and demanding VSWR tolerance (20:1 load mismatch capability).

Technical Context

This LDMOS transistor operates in common-source configuration with gate-controlled enhancement-mode conduction. Its lateral structure enables high gain (14.5 dB typ. @ 500 MHz) and excellent linearity (50% drain efficiency @ 25 W), supported by low input/output capacitances (CISS = 86 pF, COSS = 76 pF) and high transconductance (GFS = 2.5 mho).

Thermal performance is anchored by the PowerSO-10RF package's 1.2 °C/W RthJC and JEDEC-qualified SMD construction, enabling reliable operation at TJ ≤ 165°C. The device sustains 20:1 VSWR across all phase angles at full 25 W output, confirming robustness in mismatched antenna environments typical of mobile radio front-ends.

Key Specifications

Pinout & Package

The PD55025STR-E uses the PowerSO-10RF straight-lead plastic package - ST's first JEDEC-approved high-power SMD RF package, optimized for thermal conduction and RF performance with exposed drain paddle for PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF300BN and PD57015STR-E, PD55025STR-E offers optimal balance of 25 W output, 14.5 dB gain, and SMD manufacturability in 12.5 V mobile radio designs - neither over-specified nor under-binned for its target use case.

Availability

PD55025STR-E is available at Aetrix Electronics and suitable for car mobile radio transmitters, UHF land mobile radio base stations, and ISM band industrial amplifiers requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for PD55025STR-E 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, microcontroller, power, and RF components for industrial, automotive, and consumer markets.

PD55025STR-E belongs to ST's LdmoST plastic family of RF power transistors - engineered specifically for high-gain, broadband commercial and industrial amplifiers operating up to 1 GHz with superior thermal and linearity performance.

FAQ

What is the recommended gate bias voltage range for PD55025STR-E?

The gate-source threshold voltage VGS(Q) is specified at 2.0–5.0 V when ID = 100 mA and VDS = 28 V. For stable 200 mA quiescent operation at 12.5 V supply, a typical gate bias of 3.5–4.2 V is used, verified via the VGS vs. ID curve in Figure 4 of the datasheet. Exceeding 5.0 V risks gate oxide stress.

Can PD55025STR-E operate reliably at 1 GHz?

Yes - the device is characterized up to 1000 MHz with confirmed S-parameters (Table 10–13). At 1 GHz and ID = 200 mA, |S21| = 0.23 dB (≈1.7× gain) and drain efficiency remains >25%, supporting broadband driver applications. Full 25 W output is rated at 500 MHz, not 1 GHz.

Is thermal derating required above 70°C case temperature?

Yes - maximum power dissipation drops linearly beyond TC = 70°C per the 1.2 °C/W RthJC rating. At TC = 100°C, allowable PDISS = 79 W × (1 − (100−70)/165) ≈ 57 W. Layout must ensure low thermal resistance from drain paddle to PCB copper area to maintain safe junction temperature.

Does PD55025STR-E require external gate protection diodes?

While the device has ±20 V VGS rating, application note AN1294 recommends series gate resistors (10–47 Ω) and parallel 18 V Zener clamps to suppress RF-induced transients. This is critical in mobile radio environments with antenna switching noise and ESD events - the internal gate oxide is not inherently rugged enough for unclamped operation.