This part is a kind of semiconductor called STA471A.

Function of this product has NPN Darlington With built-in avalanche diode.

Manufacturers : Sanken

Image and pinout :

Some of the text within the PDF file :

STA471A Absolute maximum ratings Symbol VCBO VCEO VEBO IC ICP IB PT Tj Tstg Ratings 60±10 60±10 6 2 4 (PW≤1ms, Du≤25%) 0.5 4 (Ta=25°C) 20 (Tc=25°C) 150 –40 to +150 NPN Darlington With built-in avalanche diode (Ta=25°C) External dimensions D ••• STA400 (Ta=25°C) Electrical characteristics Symbol ICBO IEBO VCEO hFE VCE(sat) VBE(sat) VFEC ton tstg tf fT Cob 50 2000 60 5000 1.1 1.8 1.3 0.5 4.0 1.0 50 25 Specification min typ max 10 5 70 10000 1.5 2.2 1.8 V V V Unit Unit V V V A A A W °C °C Conditions VCB=50V VEB=6V IC=10mA VCE=4V, IC=1A IC=1A, IB=2mA IFEC=1A VCC 30V, IC=1A, IB1=–IB2=2mA VCE=12V, IE=–0.1A VCB=10V, f=1MHz µA mA V µs µs µs MHz pF 3 2 1 R1 R2 5 4 6 7 8 9 10 R1: 3.5kΩ typ R2: 200Ω typ Characteristic curves IC-VCE Characteristics (Typi [ ... ]

STA471A PDF Datasheet Download