STMicroelectronics PD85025S-E

Overview

PD85025S-E from STMicroelectronics is an LDMOS RF power transistor designed for UHF broadband amplifier stages in 2-way mobile radios and OFDM transmitters. It operates from 340–520 MHz, delivers 10 W PEP output power at 15 V supply, achieves ≥16.5 dB gain, and maintains stable performance under 20:1 load mismatch.

For engineers reviewing the PD85025S-E datasheet, PD85025S-E pinout, PD85025S-E application, or PD85025S-E equivalent, this device is selected for high-efficiency, thermally robust UHF final-stage amplification where harmonic suppression (H2 ≤ –37 dBc, H3 ≤ –60 dBc) and IMD3 < –27 dBc at 10 WPEP are critical.

Technical Context

The PD85025S-E is a single-ended, enhancement-mode N-channel LDMOS transistor optimized for Class AB linear operation in UHF band amplifiers. Its design supports fixed-bias or active bias control with 220 mA quiescent drain current and handles peak drain currents up to 1.25 A at 10 WPEP output.

Thermal stability is achieved without beryllium oxide (BeO), using a ceramic-metal package with low thermal resistance. The device exhibits inherent ruggedness against load mismatch-maintaining safe operation at VSWR = 20:1 across all phase angles at rated output power.

Key Specifications

Availability

PD85025S-E is available at Aetrix Electronics and suitable for UHF land-mobile radio base stations, portable repeaters, OFDM-based wireless data links, and emergency communication transceivers requiring stable component supply across extended temperature and RF stress conditions.

Supply support for PD85025S-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, designing and manufacturing analog, power, microcontroller, and RF components for industrial, automotive, and communications markets.

The PD85025S-E belongs to ST's LDMOS RF power transistor family, engineered specifically for rugged, high-efficiency UHF transmitter final stages in mission-critical two-way radio infrastructure and mobile equipment.

FAQ

What is the gate threshold voltage of the PD85025S-E?

The PD85025S-E has a typical gate threshold voltage (V_GS(th)) of +2.5 V at I_D = 1 mA, measured per STMicroelectronics characterization. This value enables reliable turn-on with standard ±5 V bias control circuits and ensures stable Class AB bias point setting at 220 mA I_DQ.

Does the PD85025S-E require external matching networks?

Yes - the PD85025S-E is not internally matched. Its input and output impedances are specified as 5 Ω (input) and 5.5 Ω (output) at mid-band (430 MHz), requiring discrete LC matching networks, as implemented on the STEVAL-TDR022V1 evaluation board using ATC 100B-series capacitors and Coilcraft A/T-series inductors.

Is the PD85025S-E RoHS compliant and lead-free?

Yes - the PD85025S-E is manufactured in full compliance with RoHS Directive 2011/65/EU and uses lead-free terminations. STMicroelectronics confirms its Pb-free status in the official device summary table (Doc ID 18079 Rev 1, p.1) and packaging specification documents dated October 2010.

Can the PD85025S-E be used in pulsed radar applications?

No - the PD85025S-E is characterized and qualified exclusively for continuous-wave and PEP-limited OFDM/2-tone modulation in land-mobile radio. ST does not specify pulse duty cycle, rise/fall time, or avalanche energy ratings; its safe operating area (SOA) is defined only for DC and RF sinusoidal/PEP conditions per Table 2.