This part is a kind of semiconductor called ST-DV709.

Function of this product has Transformer.

Manufacturers : Sumlink

Image and pinout :

Some of the text within the PDF file :

www.DataSheet.co.kr TRANSFORMERS FOR DIGITAL AUDIO DATA TRANSMISSION FEATURES For Use with Cirrus Logic’s CS8401, CS8402, CS8403 & CS8404 ICs Operating transmission rates: 1 to 7 Mbps Controlled rise time: 25 nsec MAX High isolation voltage: 2 kV MIN Electrical Specifications @ 25°C Operating Temperature 0°C to 70°C Part Number Turns Ratio Primary Inductance (mH ±20%) LL (µH) MAX Rise Time (nsec) MAX ET (V-µsec) MAX Isolation (Vrms) MIN Bandwidth (100 KHz- 55 MHz) TYP Return Loss (100 KHz- 10 MHz) MIN ST-DV709 1:1 (±5%) 2.5 0.50 25 20 2000 3 dB 20 dB Mechanicals .500 MAX 12,70 2 1 .250 MAX 6,35 .350 8,89 .130 3,30 .200 5,08 .400 10,16 Sumlink ST-DV709 4 3 (DATE CODE) Leads are 24 AWG-solderable Dimensions: Inches mm Unless otherwise specified all toler [ ... ]

ST-DV709 PDF Datasheet Download