This part is a kind of semiconductor called D1666.

Function of this product has 2SD1666.

Manufacturers : SavantIC

Image and pinout :

Some of the text within the PDF file :

SavantIC Semiconductor Silicon NPN Power Transistors DESCRIPTION ·With TO-220F package www.dat·aCshoemet4pule.cmoment to type 2SB1133 ·High reliability ·Wide area of safe operation APPLICATIONS ·For low-frequency and general-purpose amplifier applications PINNING PIN 1 2 3 DESCRIPTION Base Collector Emitter Product Specification 2SD1666 Fig.1 simplified outline (TO-220F) and symbol Absolute maximum ratings (Ta=25 ) SYMBOL PARAMETER VCBO Collector-base voltage VCEO Collector-emitter voltage VEBO Emitter-base voltage IC Collector current ICM Collector current-peak PC Collector dissipation Tj Junction temperature Tstg Storage temperature CONDITIONS Open emitter Open base Open collector Ta=25 TC=25 MAX 60 60 6 3 8 2 25 150 -40~150 UNIT V V V A A W SavantIC Semiconduc [ ... ]

D1666 PDF Datasheet Download