Infineon Technologies BFP405E6740HTSA1

Overview

BFP405E6740HTSA1 from Infineon Technologies is a low-noise silicon bipolar RF transistor in SOT343 package, designed for oscillator and amplifier stages up to 12 GHz. It delivers NFmin = 1.25 dB at 1.8 GHz, Gms = 23 dB at 1.8 GHz, fT = 25 GHz (typ), and operates at IC = 5 mA, VCE = 2 V in 50 Ω systems-used in GPS L1-band front-end LNAs and low-power RF synthesizers.

For engineers reviewing the BFP405E6740HTSA1 datasheet, BFP405E6740HTSA1 pinout, BFP405E6740HTSA1 application, or BFP405E6740HTSA1 equivalent, key selection criteria include noise figure optimization at sub-2 GHz frequencies, thermal resistance RthJS = 530 K/W, SOT343 lead visibility for solder inspection, AEC-Q101 qualification, and SPICE GP model availability for high-frequency simulation.

Technical Context

This NPN bipolar transistor uses epitaxial base technology optimized for low-noise RF amplification and stable oscillation. Its fT of 25 GHz (typ) and Ccb = 0.05 pF (typ) support operation through S-band, while ZSopt impedance varies with frequency (e.g., 50 + j25 Ω at 1.8 GHz for minimum noise).

The device exhibits strong current gain linearity: hFE = 95 (typ) at IC = 5 mA, VCE = 4 V, and maintains IP3 = 15 dBm at 1.8 GHz under matched 50 Ω terminations-enabling use in low-distortion receive paths without external bias stabilization networks.

Key Specifications

Pinout & Package

SOT343 package with visible leads, RoHS-compliant and halogen-free. Four-terminal surface-mount package with exposed emitter pad for thermal conduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BFP405E6740HTSA1, BFP640FESD offers superior high-frequency gain and noise performance but demands stricter layout control; MRF581 trades ft and NFmin for higher voltage tolerance and proven field reliability in harsh RF environments.

Availability

BFP405E6740HTSA1 is available at Aetrix Electronics and suitable for GPS receivers, ISM-band oscillators, UWB pulse amplifiers, and automotive radar IF stages requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for BFP405E6740HTSA1 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 is a German semiconductor manufacturer specializing in power management, RF, and automotive electronics, with global manufacturing and quality certification to IATF 16949.

The BFP405 belongs to Infineon's BFP family of silicon bipolar RF transistors, engineered specifically for low-noise, high-frequency analog signal conditioning in cost-sensitive consumer and automotive wireless systems.

FAQ

What is the recommended bias condition for minimum noise figure?

For NFmin = 1.25 dB at 1.8 GHz, bias at IC = 2 mA and VCE = 2 V with source impedance ZS = ZSopt = 50 + j25 Ω. The datasheet provides full ZSopt vs. frequency curves; actual PCB layout parasitics must be de-embedded before final matching network synthesis.

Does BFP405E6740HTSA1 require external ESD protection?

Yes-it is classified as ESD-sensitive (HBM Class 1B, < 250 V). Standard handling per ANSI/ESDA S20.20 is mandatory; no internal protection diodes are integrated. Input/output traces must avoid unshielded connectors or long stubs in final assembly.

Can this transistor be used in Class-C oscillator configurations?

Yes-its high fT and low Ccb enable stable fundamental oscillation up to 12 GHz in Colpitts and Clapp topologies. At VCE = 3 V and IC = 5 mA, measured phase noise is −105 dBc/Hz at 100 kHz offset from 2.45 GHz carrier, confirming suitability for timing-critical RF clocks.

Is the SPICE GP model validated for large-signal behavior?

The provided SPICE GP model is extracted and verified for DC, S-parameter, noise, and small-signal intermodulation (IP3) up to 6 GHz. Large-signal compression (P-1dB) and harmonic generation are not modeled; measurement validation is required for power amplifier applications above 5 mW output.