This part is a kind of semiconductor called SOT23.

Function of this product has LOW VOLTAGE 4ohm SPDT SWITCH.

Manufacturers : ST Microelectronics

Image and pinout :

Some of the text within the PDF file :

® STG719 LOW VOLTAGE 4Ω SPDT SWITCH s s s s HIGH SPEED: tPD = 0.3 ns (TYP.) at VCC = 5V tPD = 0.4 ns (TYP.) at VCC = 3.0V LOW POWER DISSIPATION: ICC = 1 µA (MAX.) at TA = 85 oC LOW ”ON” RESISTANCE: RON = 4Ω (MAX. Ta=25oC) AT VCC = 5V RON = 6Ω (TYP.) AT VCC = 3.0V WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 1.8V to 5.5V SINGLE SUPPLY SOT23-6L ORDER CODES PACKAGE SOT23-6L T UBE T& R STG719FTR DESCRIPTION The STG719 is an high speed SPDT CMOS SWITCH frabricated in silicon gate C2MOS technology. It is designed to operate from 1.8V to 5.5V, making this device ideal for portable applications. It offers 4Ω ON-Resistance Max at 5V 25oC. Additional key features are fast switching speed (t ON=7ns, tOFF=4.5ns) and Low Power Consumption (<0.01µW Typ.). ESD immunity is higher than [ ... ]

SOT23 PDF Datasheet Download