Infineon Technologies BFS481H6327XTSA1

Overview

BFS481H6327XTSA1 from Infineon Technologies is a low-noise silicon bipolar RF transistor pair in a single SOT363 package, configured as two galvanically isolated NPN transistors. It delivers f_T = 8 GHz, NF_min = 0.9 dB at 900 MHz, and h_FE = 70–140 (IC = 5 mA, V_CE = 8 V), targeting broadband RF amplifier stages in GSM/EDGE baseband front-ends.

For engineers reviewing the BFS481H6327XTSA1 datasheet, BFS481H6327XTSA1 pinout, BFS481H6327XTSA1 application, or BFS481H6327XTSA1 equivalent, key selection criteria include noise figure at 900 MHz/1.8 GHz, dual-transistor isolation integrity, SOT363 thermal resistance (R_thJS = 380 K/W), collector-emitter breakdown (V_CEO = 12 V), and RoHS/halogen-free compliance for automotive-qualified designs.

Technical Context

This dual NPN RF transistor supports independent biasing of TR1 and TR2 with fully isolated collector-base-emitter paths-no shared substrate or internal connection. Each transistor exhibits matched AC characteristics: C_cb = 0.23 pF (typ), C_ce = 0.13 pF (typ), and C_eb = 0.4 pF (typ) at 1 MHz, enabling stable 900 MHz–1.8 GHz small-signal amplification without cross-coupling.

The device operates within a 0.5–12 mA collector current range while maintaining NF_min ≤ 1.2 dB up to 1.8 GHz and G_ms = 20 dB (900 MHz) or G_ma = 15 dB (1.8 GHz) under matched Z_Sopt/Z_Lopt conditions-critical for cascaded LNA design where gain/noise trade-offs are tightly constrained.

Key Specifications

Pinout & Package

SOT363 (SC-88) 6-pin plastic package with visible leads, Pb-free and halogen-free per RoHS; thermal pad not present; lead finish matte tin.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise dual bipolar RF transistor applications.

Compared with BFS481H6327XTSA1, the BFS481E6327HTSA1 offers identical RF performance in alternate packaging, while MMDT3904-7-F lacks both dual-transistor isolation and UHF noise/gain capability-making it unsuitable for any application requiring <1.2 dB NF above 800 MHz.

Availability

BFS481H6327XTSA1 is available at Aetrix Electronics and suitable for GSM/EDGE receiver front-ends, automotive telematics RF amplifiers, and ISM-band 868 MHz transceivers requiring stable component supply with AEC-Q101 qualification and RoHS compliance.

Supply support for BFS481H6327XTSA1 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

Infineon Technologies AG is a German semiconductor manufacturer specializing in power management, automotive electronics, and RF solutions, headquartered in Munich.

The BFS481 belongs to Infineon's RF bipolar transistor product line, engineered specifically for high-linearity, low-noise amplification in cellular infrastructure and automotive wireless systems operating below 2 GHz.

FAQ

What is the maximum allowable collector current per transistor in BFS481H6327XTSA1?

The absolute maximum collector current per transistor is 20 mA, but the recommended operating range for optimal noise and gain performance is 0.5–12 mA. Exceeding 12 mA degrades NF_min and reduces f_T stability; simultaneous operation of both transistors above 10 mA each requires active thermal management due to P_tot derating above 83 °C solder point temperature.

Does BFS481H6327XTSA1 require external matching networks for 50 Ω systems?

Yes-while the device achieves 16 dB transducer gain into 50 Ω at 900 MHz, its S-parameters indicate strong mismatch (e.g., S11 ≈ −8 dB). External LC matching networks are required on both input and output to realize NF_min and G_ms; application note AN201 details layout-optimized microstrip solutions using 0201 passives.

How is galvanic isolation verified between TR1 and TR2 in this package?

Isolation is confirmed by measuring >10⁹ Ω resistance between all pin combinations linking TR1 (pins 1,2,3) and TR2 (pins 4,5,6) at 100 V DC, per AEC-Q101 test condition H2. No shared substrate connection exists-the die consists of two physically separate transistor islands mounted on a common leadframe with air-gap separation.

Can BFS481H6327XTSA1 be used in Class-A amplifier configurations?

Yes-it is routinely deployed in Class-A LNA stages with IC = 5–8 mA and V_CE = 8 V, delivering 20 dB G_ms and 0.9 dB NF at 900 MHz. Thermal design must ensure T_J remains ≤125 °C under continuous operation; the 380 K/W R_thJS mandates ≤10 mm² copper pour beneath pin 3 and pin 6 for reliable 150 mW total dissipation.