Infineon Technologies BFR840L3RHESDE6327XTSA1

Overview

BFR840L3RHESDE6327XTSA1 from Infineon is a SiGe:C NPN RF heterojunction bipolar transistor (HBT) with integrated ESD protection, designed for 5–6 GHz WLAN front-end amplification. It delivers NFmin = 0.65 dB at 5.5 GHz, fT = 75 GHz, Gms = 22 dB at 5.5 GHz, OIP3 = 18 dBm, and operates at V_CC = 1.8 V with 5 mA bias - ideal for low-voltage 5G Wi-Fi receiver LNA stages.

For engineers reviewing the BFR840L3RHESDE6327XTSA1 datasheet, BFR840L3RHESDE6327XTSA1 pinout, BFR840L3RHESDE6327XTSA1 application, or BFR840L3RHESDE6327XTSA1 equivalent, key selection criteria include minimum noise figure at 5.5 GHz, HBM ESD hardness (1.5 kV), TSLP-3-9 package compatibility, and DC bias constraints for 1.2/1.8 V operation.

Technical Context

This discrete RF HBT uses silicon-germanium carbon (SiGe:C) epitaxial base technology to achieve high f_T (75 GHz) and ultra-low noise performance. Its heterojunction structure enables superior electron transport and reduced base resistance versus standard Si BJTs.

The device integrates on-chip ESD protection across all pins (1.5 kV HBM), eliminating need for external TVS in compact 5 GHz RF layouts. Biasing supports dual-mode operation: low-voltage (1.2/1.8 V) for portable devices and higher supply (2.85–3.6 V) with collector resistor tuning.

Key Specifications

Pinout & Package

Supplied in TSLP-3-9 (Thin Small Leadless Package, 3-pin, 0.9 mm pitch), this leadless surface-mount device features a compact 1.1 × 0.7 × 0.37 mm footprint optimized for 5 GHz matching networks and minimal parasitic inductance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RF HBT LNA applications.

Compared with BFP740FESD and NE85633, the BFR840L3RHESDE6327XTSA1 offers the highest f_T and lowest NF_min in its class, with integrated ESD enabling smaller, more reliable 5 GHz RF layouts - making it optimal for next-generation Wi-Fi 6E/7 front ends where noise and space are critical.

Availability

BFR840L3RHESDE6327XTSA1 is available at Aetrix Electronics and suitable for WLAN 5 GHz LNA designs, satellite radio tuners, GNSS front ends, and WiMAX transceivers requiring stable component supply, consistent parametric performance, and industrial-grade reliability.

Supply support for BFR840L3RHESDE6327XTSA1 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, automotive, and security ICs, with global manufacturing and R&D infrastructure.

The BFR840L3RHESDE6327XTSA1 belongs to Infineon's high-frequency SiGe:C HBT portfolio, engineered specifically for ultra-low-noise, high-linearity RF front ends in wireless infrastructure and consumer connectivity applications.

FAQ

What is the recommended DC bias for optimal noise figure at 5.5 GHz?

For minimum noise figure (NF_min = 0.65 dB), operate at V_CE = 1.8 V and I_C = 5 mA with base bias adjusted to achieve that current. The datasheet specifies this condition explicitly in Table 12; deviation increases NF by ≥0.1 dB per 0.5 mA change in I_C.

Can BFR840L3RHESDE6327XTSA1 be used at 1.2 V supply?

Yes - the device is qualified for 1.2 V operation per the "Ideal for low voltage applications" feature list. At 1.2 V, G_ms drops to ~19 dB and NF_min rises to ~0.85 dB at 5.5 GHz, but remains functional for portable Wi-Fi clients where power efficiency outweighs peak sensitivity.

Does the TSLP-3-9 package require special PCB layout considerations?

Yes - the 0.9 mm pitch and 0.37 mm height demand strict adherence to Infineon's layout guidelines: emitter pad must connect to solid ground plane via ≥3 thermal vias, collector trace must minimize stub length to avoid resonance near 5.5 GHz, and base matching network should use EM-simulated microstrip.

Is external ESD protection needed despite the integrated solution?

No - the 1.5 kV HBM rating applies to all pins per JESD22-A114, and the internal protection is validated for industrial handling. External diodes add capacitance that degrades 5 GHz noise match and are unnecessary unless system-level ESD testing exceeds HBM 1.5 kV (e.g., IEC 61000-4-2 contact discharge).