This part is a kind of semiconductor called BFE505.
Function of this product has NPN wideband differential transistor.
Manufacturers : NXP
Image and pinout :
Some of the text within the PDF file :
DISCRETE SEMICONDUCTORS DATA SHEET BFE505 NPN wideband differential transistor Product specification Supersedes data of 1995 Sep 04 File under Discrete Semiconductors, SC14 1996 Oct 08 Philips Semiconductors Product specification NPN wideband differential transistor FEATURES • Small size • High power gain at low bias current and voltage • Temperature matched • Balanced configuration • hFE matched • Continues to operate at VCE < 1 V. APPLICATIONS • Single balanced mixers • Balanced amplifiers • Balanced oscillators. DESCRIPTION Emitter coupled dual NPN silicon RF transistor in a surface mount, 5-pin SOT353 (S-mini) package. The transistor is primarily intended for applications in the RF front end as a balanced mixer, a differential amplifier in analog and digital ce [ ... ]