Infineon Technologies BFR181WH6327XTSA1

Overview

BFR181WH6327XTSA1 from Infineon Technologies is a low-noise silicon bipolar RF transistor designed for broadband amplifier stages in 900 MHz and 1.8 GHz cellular front-ends. It delivers f_T = 8 GHz, NF_min = 0.9 dB at 900 MHz, and h_FE = 70–140 at I_C = 5 mA, V_CE = 8 V, enabling high-gain, low-noise amplification in compact SOT323 packages.

For engineers reviewing the BFR181WH6327XTSA1 datasheet, BFR181WH6327XTSA1 pinout, BFR181WH6327XTSA1 application, or BFR181WH6327XTSA1 equivalent, key selection criteria include verified noise figure at 900 MHz/1.8 GHz, SOT323 thermal resistance (R_thJS = 345 K/W), maximum stable gain (G_ms = 19 dB), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This NPN RF transistor operates with collector-emitter breakdown voltage V_(BR)CEO = 12 V and supports DC bias ranges from I_C = 0.5 mA to 12 mA. Its f_T of 8 GHz and C_cb = 0.29–0.45 pF enable stable broadband amplification up to 1.8 GHz while maintaining low inter-electrode capacitance.

The device uses emitter-grounded configuration with base-emitter cutoff current I_EBO ≤ 1 µA and collector-base cutoff current I_CBO ≤ 100 nA, ensuring low leakage in low-power RF gain blocks. Its Z_Sopt-matched noise performance is validated at 900 MHz and 1.8 GHz under pulsed conditions per Infineon's test methodology.

Key Specifications

Pinout & Package

Package: SOT323 - surface-mount plastic package with visible leads, RoHS-compliant and halogen-free, qualified per AEC-Q101.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BFR193WH6327XTSA1 and MRF581W, the BFR181WH6327XTSA1 uniquely balances 8 GHz f_T, sub-1 dB noise, and SOT323 space efficiency-making it optimal for cost- and size-sensitive 900 MHz/1.8 GHz portable RF front-ends.

Availability

BFR181WH6327XTSA1 is available at Aetrix Electronics and suitable for GSM/EDGE handset design, automotive telematics modules, and portable GPS front-ends requiring stable component supply and AEC-Q101 compliance.

Supply support for BFR181WH6327XTSA1 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, RF, and automotive ICs, with global R&D and manufacturing infrastructure.

The BFR181W series belongs to Infineon's RF bipolar transistor portfolio, engineered specifically for low-noise, high-gain amplification in 800–2000 MHz wireless infrastructure and mobile terminal applications.

FAQ

What is the recommended DC bias condition for minimum noise figure?

The datasheet specifies NF_min = 0.9 dB at I_C = 2 mA, V_CE = 8 V, with source impedance Z_S = Z_Sopt. This bias point balances low noise and adequate gain; deviation increases NF by ≥0.2 dB per 0.5 mA shift in I_C. Stable operation requires base resistor network design to maintain this quiescent point across temperature.

Is BFR181WH6327XTSA1 suitable for 5G sub-6 GHz applications?

No-its f_T = 8 GHz and verified G_ma = 13.5 dB at 1.8 GHz indicate diminishing gain and rising NF above 2.5 GHz. It is optimized for 900 MHz and 1.8 GHz bands only; for n77/n78 5G bands (3.3–3.8 GHz), devices with f_T ≥ 20 GHz and dedicated 5G matching networks are required.

How does the SOT323 package affect thermal performance in continuous operation?

With R_thJS = 345 K/W, the SOT323 limits continuous P_tot to 175 mW at T_S ≤ 90 °C. At ambient 85 °C, junction temperature reaches 150 °C at ~120 mW-requiring derating below 100 mW for long-term reliability. PCB copper area under the collector lead must exceed 25 mm² to sustain rated power.

Does this part require external ESD protection in circuit design?

Yes-the device is ESD-sensitive (HBM Class 1B per JESD22-A114). Although it meets AEC-Q101 ESD requirements internally, layout best practices mandate 100 Ω series resistors on base/emitter lines and TVS diodes on collector if exposed to external connectors. No internal protection diodes are integrated.