This part is a kind of semiconductor called BF904A.
Function of this product has N-channel dual gate MOS-FETs.
Manufacturers : NXP
Image and pinout :

Some of the text within the PDF file :
DISCRETE SEMICONDUCTORS DATA SHEET BF904A; BF904AR; BF904AWR N-channel dual gate MOS-FETs Product specification Supersedes data of 1999 Feb 01 1999 May 14 Philips Semiconductors Product specification N-channel dual gate MOS-FETs FEATURES • Specially designed for use at 5 V supply voltage • Short channel transistor with high transfer admittance to input capacitance ratio • Low noise gain controlled amplifier up to 1 GHz • Superior cross-modulation performance during AGC. APPLICATIONS • VHF and UHF applications with 3 to 7 V supply voltage such as television tuners and professional communications equipment. DESCRIPTION Enhancement type field-effect transistors. The transistors consist of an amplifier MOS-FET with source and substrate interconnected and an internal bias circu [ ... ]
BF904A PDF Datasheet Download
