NXP Semiconductors BLF988S,112

Overview

BLF988S,112 from NXP Semiconductors is a 600 W LDMOS RF power transistor designed for broadband transmitter applications in the 500–1000 MHz range. It delivers 20 dB power gain and 58% drain efficiency at 860 MHz in pulsed class-AB operation, with rugged VSWR ≥ 40:1 tolerance, making it suitable for high-reliability broadcast and industrial RF amplifiers.

For engineers reviewing the BLF988S,112 datasheet, BLF988S,112 pinout, BLF988S,112 application, or BLF988S,112 equivalent, key selection criteria include its 0.15 K/W junction-to-case thermal resistance, dual-gate/dual-drain configuration for balanced push-pull designs, 110 V drain-source breakdown voltage, and earless flanged ceramic SOT539B package optimized for high-power RF thermal management.

Technical Context

The BLF988S,112 is a laterally diffused metal-oxide semiconductor (LDMOS) device configured as a balanced dual-gate, dual-drain RF power transistor. Its internal input matching enables stable broadband gain across 500–1000 MHz without external tuning networks.

It operates in common-source class-AB mode with 50 V drain bias and 1.3 A quiescent drain current. The device supports both narrowband (e.g., 860 MHz single-tone) and two-tone RF test conditions, delivering 600 W peak output power and −32 dBc third-order intermodulation distortion under specified test circuit conditions.

Key Specifications

Pinout & Package

BLF988S,112 uses the earless flanged balanced ceramic SOT539B package, featuring a thermally optimized metal flange for direct heatsink attachment and four isolated leads (two drains, two gates, one shared source).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BLF988S,112, the BLF988,112 offers identical RF performance in a mechanically distinct flanged package, while the MRF9001NBR1 trades ruggedness and proven UHF stability for higher-frequency capability and raw power density-requiring redesign of bias, matching, and thermal subsystems.

Availability

BLF988S,112 is available at Aetrix Electronics and suitable for FM/TV broadcast transmitters, land mobile radio base stations, and industrial RF heating systems requiring stable component supply, long-lifecycle support, and traceable sourcing for high-reliability deployments.

Supply support for BLF988S,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 company headquartered in Eindhoven, Netherlands, specializing in high-performance analog, RF, and power management solutions for industrial, automotive, and communications markets.

The BLF988S,112 belongs to NXP's LDMOS RF power transistor product line, engineered specifically for high-efficiency, high-ruggedness UHF transmitter applications where thermal stability and load mismatch tolerance are critical design requirements.

FAQ

What is the maximum continuous drain current for BLF988S,112?

The BLF988S,112 has a typical quiescent drain current (I_Dq) of 1.3 A per section under 50 V drain bias and 25 °C case temperature. Its absolute maximum continuous drain current is not explicitly specified, but the device is rated for 600 W peak output power in pulsed class-AB operation with 20% duty cycle and 100 µs pulse width-indicating robust short-duration current handling well above steady-state limits. Always refer to the recommended operating conditions in the official BLF988S,112 datasheet for safe biasing.

Does BLF988S,112 require external input matching networks?

No, the BLF988S,112 features internal input matching optimized for high gain and broadband operation from 500 MHz to 1000 MHz. This eliminates the need for external input matching components in most standard amplifier configurations, simplifying PCB layout and improving repeatability. However, output matching remains application-specific and must be designed per the target load impedance and harmonic suppression requirements outlined in the BLF988S,112 application notes.

What is the thermal resistance from junction to case for BLF988S,112?

The BLF988S,112 has a typical thermal resistance from junction to case (R_th(j-c)) of 0.15 K/W, measured under RF conditions at T_case = 80 °C and P_L(AV) = 250 W. This value is confirmed in Table 5 of the official BLF988S,112 datasheet and reflects the device's optimized ceramic-flange construction for efficient heat transfer to the heatsink. Proper mechanical mounting with thermal interface material is essential to achieve this rating in practice.

Can BLF988S,112 be used in push-pull amplifier configurations?

Yes, the BLF988S,112 is explicitly designed for push-pull operation, with separate gate and drain terminals (Pins 1–4) and a common source (Pin 5). Its balanced dual-gate/dual-drain architecture enables true complementary drive and symmetrical power combining. Impedance data in Table 9 of the BLF988S,112 datasheet provides simulated Z_i and Z_L values for push-pull configurations at 50 V and 600 W, confirming its suitability for high-efficiency, low-distortion RF amplifier topologies.

Is BLF988S,112 RoHS compliant?

Yes, the BLF988S,112 is compliant with Directive 2002/95/EC on the Restriction of Hazardous Substances (RoHS), as stated in Section 1.2 "Features and benefits" of the official BLF988S,112 objective data sheet. This confirms that the device contains lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls (PBB), and polybrominated diphenyl ethers (PBDE) below the maximum concentration values defined by the directive, supporting environmentally responsible manufacturing and end-of-life handling.