RF transistor for low-noise, high-gain front-ends
The BFP840FESDH6327XTSA1: NPN RF bipolar transistor in a PG-TSFP-4-1 package. Transition frequency of 85GHz and typical gain of 35dB.
Package and mounting for RF layout
The PG-TSFP-4-1 package is a 4-lead flat-lead SMD with a small footprint — the leads are coplanar with the body, which minimizes parasitic inductance and supports repeatable RF performance up to several tens of gigahertz. Surface-mount assembly is standard; the flat leads require a solder paste stencil aperture sized to the pad geometry in the Infineon application note. The device is rated for a junction temperature of 150°C, so thermal management is straightforward at the 75mW maximum power dissipation.