STMicroelectronics PD85025C

Overview

PD85025C from STMicroelectronics is a common-source N-channel enhancement-mode lateral DMOS RF power transistor in the LDMOST family, rated for 40 V drain-source voltage, 7 A continuous drain current, and delivering 25 W output power at 945 MHz with 16 dB gain under 13.6 V supply. It is designed for broadband commercial and industrial RF amplification up to 1 GHz, including cellular base station driver stages.

For engineers reviewing the PD85025C datasheet, PD85025C pinout, PD85025C application, or PD85025C equivalent, key selection criteria include its 1.4 °C/W junction-to-case thermal resistance, BeO-free M243 hermetic package, ESD protection (HBM Class 2, MM Class M3), and linearity performance validated at P3dB = 25–30 W with 60–73% drain efficiency.

Technical Context

The PD85025C operates in common-source configuration with gate-controlled lateral conduction, optimized for high-gain RF amplification up to 1 GHz. Its static characteristics include V(BR)DSS = 40 V, IDSS ≤ 1 µA, and CISS = 49 pF at 12.5 V - enabling stable biasing and broadband matching.

Dynamically, it delivers P3dB = 25–30 W at 945 MHz with 15–17.5 dB power gain and 60–73% drain efficiency under 13.6 V/300 mA quiescent conditions. Its impedance data (ZIN = 1.01 + j2.03 Ω, ZDL = 1.75 + j2.20 Ω at 945 MHz) supports 50 Ω system integration with minimal external matching.

Key Specifications

Pinout & Package

The PD85025C is housed in an epoxy-sealed, BeO-free, flanged M243 hermetic package (2-lead, non-hermetic variant not applicable), compliant with ECOPACK® environmental standards and JEDEC JESD97 marking for lead-free interconnect.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MRF6VP2450HR6 and PD57018-E, the PD85025C offers balanced 25 W output, proven 945 MHz linearity, and M243 package compatibility - making it optimal for cost-sensitive, thermally managed 900 MHz driver stages where BeO-free compliance is mandatory.

Availability

PD85025C is available at Aetrix Electronics and suitable for cellular base station drivers, industrial RF heating generators, land mobile radio repeaters, and GSM/EDGE infrastructure requiring stable component supply and long-term manufacturability.

Supply support for PD85025C 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 communications markets.

The PD85025C belongs to ST's LDMOST RF power transistor product line, engineered specifically for high-efficiency, high-linearity, and thermally robust amplification in 800–1000 MHz commercial wireless infrastructure.

FAQ

What is the recommended gate bias voltage for linear operation at 945 MHz?

The PD85025C achieves optimal linearity and efficiency at IDQ = 300 mA with VGS(Q) ≈ 5.5 V (typical, per Figure 9). This bias point yields 16 dB gain and 73% drain efficiency at P3dB. Gate voltage must be stabilized using low-thermal-drift resistors and bypassed with RF chokes and decoupling capacitors to prevent oscillation.

Can PD85025C operate at 28 V supply for higher output power?

No - the absolute maximum V(BR)DSS is 40 V, but the device is characterized and qualified only at 13.6 V and 17 V (for VSWR testing). Operation above 17 V violates the specified safe operating area and risks premature failure due to avalanche stress and thermal runaway; ST does not guarantee performance or reliability beyond 17 V.

Is the M243 package compatible with standard TO-247 heatsinks?

No - the M243 (.230 × .360 inch 2-lead flanged package) has distinct mechanical dimensions (E = 20.07–20.57 mm, F = 8.89–9.40 mm) and mounting hole pattern versus TO-247. Direct mechanical interchange is not possible; custom heatsink fixtures or adapter plates are required for thermal interface integrity.

Does PD85025C require external ESD protection on the gate?

While the device integrates on-chip ESD protection rated Class 2 HBM and Class M3 MM, external gate protection (e.g., 100 Ω series resistor + 12 V TVS diode to source) is strongly recommended in production assemblies to prevent damage during board handling, tuning, or transient coupling - especially in high-volume RF test environments.