This part is a kind of semiconductor called SJ4558.

Function of this product has Low-noise dual operational amplifier circuit suitable.

Manufacturers : SJ

Image and pinout :

Some of the text within the PDF file :

1. SJ4558 VNI = 2.5uV BW = 3MHz DIP8 /SOP8 2. 1 SJ4558 2 URL:http://www.szsanjing.com -- TEL: 0755-29663136 FAX: 0755-29663137 -- page:1/6 3. 1 Tamb=25 SJ4558 2 Tamb=25 Vcc=15 Vee=-15V URL:http://www.szsanjing.com -- TEL: 0755-29663136 FAX: 0755-29663137 -- page:2/6 SJ4558 URL:http://www.szsanjing.com -- TEL: 0755-29663136 FAX: 0755-29663137 -- page:4/6 SJ4558 URL:http://www.szsanjing.com -- TEL: 0755-29663136 FAX: 0755-29663137 -- page:5/6 7. 1 DIP8 SJ4558 2 SOPP8 URL:http://www.szsanjing.com -- TEL: 0755-29663136 FAX: 0755-29663137 -- page:6/6 [ ... ]

SJ4558 PDF Datasheet Download