NXP Semiconductors BLF888BS,112

Overview

BLF888BS,112 from NXP Semiconductors is a 650 W UHF LDMOS RF power transistor designed for broadcast and industrial transmitter applications in the 470–860 MHz band. It delivers 120 W average output power at 858 MHz under DVB-T (8k OFDM) conditions, with 21 dB power gain, 33 % drain efficiency, and −31 dBc intermodulation distortion shoulder. Its ruggedness supports high-reliability digital modulation schemes including DVB-T.

For engineers reviewing the BLF888BS,112 datasheet, BLF888BS,112 pinout, BLF888BS,112 application, or BLF888BS,112 equivalent, this page provides verified thermal resistance (0.15 K/W), broadband impedance data (Zi/ZL across 300–1000 MHz), PAR handling (8.2 dB at 0.01 % CCDF), and flanged ceramic SOT539B package details - all critical for UHF PA design, thermal management, and matching network synthesis.

Technical Context

The BLF888BS,112 is a balanced dual-gate/dual-drain LDMOS transistor optimized for class-AB operation in common-source configurations. It features internal input matching for broadband gain stability and operates at V_DS = 50 V with I_Dq = 1.3 A quiescent current, supporting both narrowband (860 MHz 2-tone) and broadband DVB-T waveforms.

Its push-pull architecture enables high-power linear amplification with measured IMDshldr of −31 dBc and PAR of 8.2 dB in DVB-T mode. Thermal performance is defined by R_th(j-c) = 0.15 K/W under RF load, enabling robust operation up to T_j = 200 °C with case temperature maintained at 80 °C.

Key Specifications

Pinout & Package

SOT539B is an earless flanged balanced ceramic package with 4 leads and metal flange thermally/electrically connected to source (Pin 5). The flange requires mechanical mounting and electrical grounding for optimal RF performance and thermal conduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UHF LDMOS power amplifier applications.

Compared with BLF888BS,112, the BLF888B,112 offers identical RF and thermal performance in a mechanically compatible but non-interchangeable flanged package, while the MRF8S21100HR5 serves a different frequency band and power class entirely - making BLF888BS,112 uniquely suited for 470–860 MHz broadcast-grade amplification.

Availability

BLF888BS,112 is available at Aetrix Electronics and suitable for UHF broadcast transmitters, DVB-T infrastructure, industrial RF heating systems, and public safety wireless repeaters requiring stable component supply and long-term production continuity.

Supply support for BLF888BS,112 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

NXP Semiconductors is a global semiconductor leader specializing in high-performance RF power solutions for broadcast, industrial, and communications infrastructure.

The BLF888BS,112 belongs to NXP's UHF LDMOS transistor product line, engineered specifically for high-efficiency, high-linearity amplification in digital terrestrial television and industrial RF systems operating between 470 MHz and 860 MHz.

FAQ

What is the maximum junction temperature rating for BLF888BS,112?

The BLF888BS,112 has a maximum junction temperature (T_j) rating of 200 °C, as specified in Table 4 of the NXP datasheet. This high thermal limit supports reliable operation in high-power UHF transmitter applications where sustained RF loading generates significant heat. Proper heatsinking using the flanged SOT539B package is required to maintain safe junction temperatures during continuous operation.

Does BLF888BS,112 require external input matching components?

No, BLF888BS,112 incorporates internal input matching optimized for broadband operation from 470 MHz to 860 MHz. As stated in Section 1.2, it is "designed for broadband operation" with "internal input matching for high gain and optimum broadband operation." This eliminates the need for external matching networks at the gate inputs, simplifying PCB layout and improving consistency across frequency bands.

What is the typical drain efficiency of BLF888BS,112 in DVB-T mode?

The BLF888BS,112 achieves a typical drain efficiency (η_D) of 33 % at 858 MHz under DVB-T (8k OFDM) conditions with 120 W average output power and V_DS = 50 V, as confirmed in Table 7 of the datasheet. This efficiency level balances linearity and thermal output, enabling practical thermal management in broadcast transmitter final stages.

Is BLF888BS,112 RoHS compliant?

Yes, BLF888BS,112 is compliant with the Restriction of Hazardous Substances (RoHS) Directive 2002/95/EC, as explicitly stated in Section 1.2 ("Features and benefits") of the NXP datasheet. This compliance ensures suitability for environmentally regulated broadcast infrastructure and industrial equipment deployed in EU and other RoHS-aligned markets.

How does the thermal resistance of BLF888BS,112 compare to similar UHF power transistors?

BLF888BS,112 has a typical junction-to-case thermal resistance (R_th(j-c)) of 0.15 K/W, measured under RF conditions at T_case = 80 °C and P_L(AV) = 125 W (Table 5). This value is among the lowest in its class, enabling superior heat transfer to the heatsink compared to alternatives like the MRF8S21100HR5 (R_th(j-c) ≈ 0.35 K/W), directly supporting higher average power capability and longer lifetime.